From garethbranwyn at comcast.net Wed Dec 5 22:11:05 2007 From: garethbranwyn at comcast.net (Gareth Branwyn) Date: Wed Dec 5 22:11:10 2007 Subject: [dorkbotdc-blabber] "Review" of Last Week's Dorkbot DC Message-ID: Chris, of EchoDitto Labs, did a really nice write-up about the November Dorkbot DC: Dorkbot Roundup http://labs.echoditto.com/node/53 One correction to the piece (and something I should have made clear), I did not take the photos. Most of them were by Scott Beale of Laughing Squid, a few by Make's very own Brian Jepson, and a couple by Jillian Northrup of Because We Can. - Gareth -------------- next part -------------- An HTML attachment was scrubbed... URL: http://music.columbia.edu/pipermail/dorkbotdc-blabber/attachments/20071205/4d8c3ae7/attachment.html From jon at joss.com Thu Dec 6 00:16:01 2007 From: jon at joss.com (Jon Singer) Date: Thu Dec 6 00:16:19 2007 Subject: [dorkbotdc-blabber] Handmade (non-electronic) music from Indonesia -- Message-ID: <7DBEB793-A5FB-4FBF-B8F9-851FBC1D6C7F@joss.com> Hi, gang. I've been asked to post a heads-up about some music I'm involved in. Balinese gamelan was crucially important to Colin McPhee, and worked its way into a certain sector of modern music through him. Various other composers have also been influenced by Balinese, Javanese, and/or other Indonesian musical traditions. ------------------- This Thursday evening (December 6), there will be a Balinese gamelan event that will be open to the public, at the University of Maryland in College Park. This is less formal than a performance; the Balinese gamelan group at the University and Gamelan Mitra Kusuma are effectively having a rehearsal for each other. I believe that the event will take place at the Clarice Smith Performing Arts Center, and I think it begins at 7 pm. (Unfortunately, the event is so informal that it doesn't seem to be listed on the Center's calendar, but the office may know about it. You can try calling them at 301 405 2787.) ------------------ Friday evening, December 14th, there will be a Balinese gamelan performance by Gamelan Mitra Kusuma at the Indonesian Embassy, 2020 Massachusetts Ave., in DC. This is in the Dupont Circle area, just a couple blocks from the Metro. The performance is free and open to the public, but if you'd like to attend you need to RSVP to the Embassy to let them know. http://www.embassyofindonesia.org 202 775 5200 (I just hope they have someone on the front desk who is aware of this event, as I am not finding anything about it on their Website.) ------------------- Gamelan Mitra Kusuma info, if anyone wants it: http://www.dcgamelan.com ----------------------------------------------------- Cheers -- jon From dorkbotdc at dorkbot.org Thu Dec 6 01:16:46 2007 From: dorkbotdc at dorkbot.org (Dorkbot DC) Date: Thu Dec 6 01:17:04 2007 Subject: [dorkbotdc-blabber] Dorkbot DC + Make DC workshop: show of hands Message-ID: <475793CE.8050600@dorkbot.org> Howdy dorks, We need a show of hands to see how many of you are interested in attending the 16 January 2008, 7-9pm, joint Dorkbot DC + Make: DC (always FREE, except for materials) workshop meeting at the Marian Koshland Science Museum of the National Academy of Sciences (@ 5th & E Sts, NW DC). We'll be building the LED cube: http://tinyurl.com/yoddhh We're trying to get volume discounts on materialss for the workshop and it would help to see how much *serious* interest there is out there. What say you? Thanks, Alberto From mattbillings at gmail.com Thu Dec 6 08:45:59 2007 From: mattbillings at gmail.com (M@) Date: Thu Dec 6 08:46:03 2007 Subject: [dorkbotdc-blabber] Dorkbot DC + Make DC workshop: show of hands In-Reply-To: <475793CE.8050600@dorkbot.org> References: <475793CE.8050600@dorkbot.org> Message-ID: <6fbef75d0712060545y158049c8p6bd650347adafe49@mail.gmail.com> I'm in. m@ On Dec 6, 2007 1:16 AM, Dorkbot DC wrote: > Howdy dorks, > > We need a show of hands to see how many of you are interested in > attending the 16 January 2008, 7-9pm, joint Dorkbot DC + Make: DC > (always FREE, except for materials) workshop meeting at the Marian > Koshland Science Museum of the National Academy of Sciences (@ 5th & E > Sts, NW DC). We'll be building the LED cube: > > http://tinyurl.com/yoddhh > > We're trying to get volume discounts on materialss for the workshop and > it would help to see how much *serious* interest there is out there. > > What say you? > > Thanks, > > Alberto > > > > ........................................................................ > .......dorkbot dc: people doing strange things with electricity......... > ................... http://dorkbot.org/dorkbotdc ....................... > ........................................................................ > -- -------- "Actually I make more money selling magazines than I ever did at Initrode!" From mattbillings at gmail.com Thu Dec 6 08:45:59 2007 From: mattbillings at gmail.com (M@) Date: Thu Dec 6 08:46:06 2007 Subject: [dorkbotdc-blabber] Dorkbot DC + Make DC workshop: show of hands In-Reply-To: <475793CE.8050600@dorkbot.org> References: <475793CE.8050600@dorkbot.org> Message-ID: <6fbef75d0712060545y158049c8p6bd650347adafe49@mail.gmail.com> I'm in. m@ On Dec 6, 2007 1:16 AM, Dorkbot DC wrote: > Howdy dorks, > > We need a show of hands to see how many of you are interested in > attending the 16 January 2008, 7-9pm, joint Dorkbot DC + Make: DC > (always FREE, except for materials) workshop meeting at the Marian > Koshland Science Museum of the National Academy of Sciences (@ 5th & E > Sts, NW DC). We'll be building the LED cube: > > http://tinyurl.com/yoddhh > > We're trying to get volume discounts on materialss for the workshop and > it would help to see how much *serious* interest there is out there. > > What say you? > > Thanks, > > Alberto > > > > ........................................................................ > .......dorkbot dc: people doing strange things with electricity......... > ................... http://dorkbot.org/dorkbotdc ....................... > ........................................................................ > -- -------- "Actually I make more money selling magazines than I ever did at Initrode!" From Paul.McCord at USPTO.GOV Thu Dec 6 08:49:45 2007 From: Paul.McCord at USPTO.GOV (McCord, Paul) Date: Thu Dec 6 08:50:00 2007 Subject: [dorkbotdc-blabber] Dorkbot DC + Make DC workshop: show of hands In-Reply-To: <475793CE.8050600@dorkbot.org> Message-ID: <84A6ED7C13614644BD99C29FCB3329E8045B2D93@EXCHANGE2.uspto.gov> Making it to make event. Will help build, will not build personally. Any chance that Alberto will present on the Remembrancer software in the New Year? Paul -----Original Message----- From: dorkbotdc-blabber-bounces@music.columbia.edu [mailto:dorkbotdc-blabber-bounces@music.columbia.edu] On Behalf Of Dorkbot DC Sent: Thursday, December 06, 2007 1:17 AM To: A discussion list for dorkbot-dc Subject: [dorkbotdc-blabber] Dorkbot DC + Make DC workshop: show of hands Howdy dorks, We need a show of hands to see how many of you are interested in attending the 16 January 2008, 7-9pm, joint Dorkbot DC + Make: DC (always FREE, except for materials) workshop meeting at the Marian Koshland Science Museum of the National Academy of Sciences (@ 5th & E Sts, NW DC). We'll be building the LED cube: http://tinyurl.com/yoddhh We're trying to get volume discounts on materialss for the workshop and it would help to see how much *serious* interest there is out there. What say you? Thanks, Alberto ........................................................................ .......dorkbot dc: people doing strange things with electricity......... ................... http://dorkbot.org/dorkbotdc ....................... ........................................................................ From alberto.gaitan at gmail.com Thu Dec 6 09:53:47 2007 From: alberto.gaitan at gmail.com (=?ISO-8859-1?Q?Alberto_Gait=E1n?=) Date: Thu Dec 6 09:53:52 2007 Subject: [dorkbotdc-blabber] Dorkbot DC + Make DC workshop: show of hands In-Reply-To: <84A6ED7C13614644BD99C29FCB3329E8045B2D93@EXCHANGE2.uspto.gov> References: <84A6ED7C13614644BD99C29FCB3329E8045B2D93@EXCHANGE2.uspto.gov> Message-ID: <47580CFB.6030203@gmail.com> I'm down for February, Paul. ...barring blizzards, in which case it'll be March. Thanks for bearing with me! Alberto On 12/6/07 8:49 AM, Paul McCord wrote: > Making it to make event. Will help build, will not build personally. Any > chance that Alberto will present on the Remembrancer software in the New > Year? > Paul > From Paul.McCord at USPTO.GOV Thu Dec 6 10:05:25 2007 From: Paul.McCord at USPTO.GOV (McCord, Paul) Date: Thu Dec 6 10:05:41 2007 Subject: [dorkbotdc-blabber] Dorkbot DC + Make DC workshop: show of hands In-Reply-To: <47580CFB.6030203@gmail.com> Message-ID: <84A6ED7C13614644BD99C29FCB3329E8045B2D96@EXCHANGE2.uspto.gov> Any recommended reading on pipes between now and then. Ultimately I'd like to use pipes to generate algorithmic music through MAX-->MIDI. Thanks Paul -----Original Message----- From: dorkbotdc-blabber-bounces@music.columbia.edu [mailto:dorkbotdc-blabber-bounces@music.columbia.edu] On Behalf Of Alberto Gait?n Sent: Thursday, December 06, 2007 9:54 AM To: A discussion list for dorkbot-dc Subject: Re: [dorkbotdc-blabber] Dorkbot DC + Make DC workshop: show of hands I'm down for February, Paul. ...barring blizzards, in which case it'll be March. Thanks for bearing with me! Alberto On 12/6/07 8:49 AM, Paul McCord wrote: > Making it to make event. Will help build, will not build personally. Any > chance that Alberto will present on the Remembrancer software in the New > Year? > Paul > ........................................................................ .......dorkbot dc: people doing strange things with electricity......... ................... http://dorkbot.org/dorkbotdc ....................... ........................................................................ From alberto.gaitan at gmail.com Thu Dec 6 10:26:12 2007 From: alberto.gaitan at gmail.com (=?ISO-8859-1?Q?Alberto_Gait=E1n?=) Date: Thu Dec 6 10:27:03 2007 Subject: [dorkbotdc-blabber] Dorkbot DC + Make DC workshop: show of hands In-Reply-To: <84A6ED7C13614644BD99C29FCB3329E8045B2D96@EXCHANGE2.uspto.gov> References: <84A6ED7C13614644BD99C29FCB3329E8045B2D96@EXCHANGE2.uspto.gov> Message-ID: <47581494.3020509@gmail.com> I'd just read the forums and the online documentation. Because it's still in Beta, Pipes hasn't been written about too much. I found everything I needed to know in the forums and Help pages. Another helpful activity is to look at others' pipes. Otherwise, I'd read about XML and RSS so you understand the structure of the feeds. That'll help your expectations and dream up possibilities. A On 12/6/07 10:05 AM, McCord, Paul wrote: > Any recommended reading on pipes between now and then. Ultimately I'd like to use pipes to generate algorithmic music through MAX-->MIDI. > Thanks > Paul > > -----Original Message----- > From: dorkbotdc-blabber-bounces@music.columbia.edu [mailto:dorkbotdc-blabber-bounces@music.columbia.edu] On Behalf Of Alberto Gait?n > Sent: Thursday, December 06, 2007 9:54 AM > To: A discussion list for dorkbot-dc > Subject: Re: [dorkbotdc-blabber] Dorkbot DC + Make DC workshop: show of hands > > I'm down for February, Paul. ...barring blizzards, in which case it'll > be March. Thanks for bearing with me! > > Alberto > > On 12/6/07 8:49 AM, Paul McCord wrote: >> Making it to make event. Will help build, will not build personally. Any >> chance that Alberto will present on the Remembrancer software in the New >> Year? >> Paul >> > ........................................................................ > .......dorkbot dc: people doing strange things with electricity......... > ................... http://dorkbot.org/dorkbotdc ....................... > ........................................................................ > > > ........................................................................ > .......dorkbot dc: people doing strange things with electricity......... > ................... http://dorkbot.org/dorkbotdc ....................... > ........................................................................ > From ederlyn.lacson at gmail.com Thu Dec 6 10:31:36 2007 From: ederlyn.lacson at gmail.com (E. Lacson) Date: Thu Dec 6 10:31:39 2007 Subject: [dorkbotdc-blabber] Dorkbot DC + Make DC workshop: show of hands In-Reply-To: <475793CE.8050600@dorkbot.org> References: <475793CE.8050600@dorkbot.org> Message-ID: I'm in for the January MAKE! -Ederlyn On Dec 6, 2007 1:16 AM, Dorkbot DC wrote: > Howdy dorks, > > We need a show of hands to see how many of you are interested in > attending the 16 January 2008, 7-9pm, joint Dorkbot DC + Make: DC > (always FREE, except for materials) workshop meeting at the Marian > Koshland Science Museum of the National Academy of Sciences (@ 5th & E > Sts, NW DC). We'll be building the LED cube: > > http://tinyurl.com/yoddhh > > We're trying to get volume discounts on materialss for the workshop and > it would help to see how much *serious* interest there is out there. > > What say you? > > Thanks, > > Alberto > > > > ........................................................................ > .......dorkbot dc: people doing strange things with electricity......... > ................... http://dorkbot.org/dorkbotdc ....................... > ........................................................................ > -- +++ Ederlyn Lacson ederlyn.lacson@gmail.com -------------- next part -------------- An HTML attachment was scrubbed... URL: http://music.columbia.edu/pipermail/dorkbotdc-blabber/attachments/20071206/52c6740b/attachment.html From rmadams at epotential.com Thu Dec 6 11:49:43 2007 From: rmadams at epotential.com (R. Mark Adams, Ph.D.) Date: Thu Dec 6 11:49:51 2007 Subject: [dorkbotdc-blabber] Dorkbot DC + Make DC workshop: show of hands In-Reply-To: <475793CE.8050600@dorkbot.org> References: <475793CE.8050600@dorkbot.org> Message-ID: <47806.156.80.162.88.1196959783.squirrel@mail4.webfaction.com> Count me in, along with my two kids for the meeting. Can you count us for two kits? Thanks! -Mark Dorkbot DC wrote: > Howdy dorks, > > We need a show of hands to see how many of you are interested in > attending the 16 January 2008, 7-9pm, joint Dorkbot DC + Make: DC > (always FREE, except for materials) workshop meeting at the Marian > Koshland Science Museum of the National Academy of Sciences (@ 5th & E > Sts, NW DC). We'll be building the LED cube: > > http://tinyurl.com/yoddhh > > We're trying to get volume discounts on materialss for the workshop and > it would help to see how much *serious* interest there is out there. > > What say you? > > Thanks, > > Alberto > > > > ........................................................................ > .......dorkbot dc: people doing strange things with electricity......... > ................... http://dorkbot.org/dorkbotdc ....................... > ........................................................................ > > -- | | "Information is light. | | R. Mark Adams, Ph.D. | Information in itself, | | Computational Biologist | about anything, is light." | | rmadams@epotential.com | - Tom Stoppard | From ehs at pobox.com Thu Dec 6 12:37:24 2007 From: ehs at pobox.com (Ed Summers) Date: Thu Dec 6 12:37:27 2007 Subject: [dorkbotdc-blabber] Dorkbot DC + Make DC workshop: show of hands In-Reply-To: <47806.156.80.162.88.1196959783.squirrel@mail4.webfaction.com> References: <475793CE.8050600@dorkbot.org> <47806.156.80.162.88.1196959783.squirrel@mail4.webfaction.com> Message-ID: +1 ed summers From mark at steamermedia.com Thu Dec 6 12:47:55 2007 From: mark at steamermedia.com (Mark N. Boszko) Date: Thu Dec 6 12:48:02 2007 Subject: [dorkbotdc-blabber] Dorkbot DC + Make DC workshop: show of hands In-Reply-To: <475793CE.8050600@dorkbot.org> References: <475793CE.8050600@dorkbot.org> Message-ID: <8FBCA5F5-C454-4F16-9BD6-9E29F20DDA2F@steamermedia.com> Definitely serious. May bring my kids. I have two soldering irons, so could bring to share, if needed, though I'm not sure how good the tip is for fine work. On Dec 6, 2007, at 1:16 AM, Dorkbot DC wrote: > Howdy dorks, > > We need a show of hands to see how many of you are interested in > attending the 16 January 2008, 7-9pm, joint Dorkbot DC + Make: DC > (always FREE, except for materials) workshop meeting at the Marian > Koshland Science Museum of the National Academy of Sciences (@ 5th & > E Sts, NW DC). We'll be building the LED cube: > > http://tinyurl.com/yoddhh > > We're trying to get volume discounts on materialss for the workshop > and it would help to see how much *serious* interest there is out > there. > > What say you? > > Thanks, > > Alberto > > > > ........................................................................ > .......dorkbot dc: people doing strange things with > electricity......... > ................... http://dorkbot.org/ > dorkbotdc ....................... > ........................................................................ From mark at steamermedia.com Thu Dec 6 12:47:55 2007 From: mark at steamermedia.com (Mark N. Boszko) Date: Thu Dec 6 12:48:02 2007 Subject: [dorkbotdc-blabber] Dorkbot DC + Make DC workshop: show of hands In-Reply-To: <475793CE.8050600@dorkbot.org> References: <475793CE.8050600@dorkbot.org> Message-ID: <8FBCA5F5-C454-4F16-9BD6-9E29F20DDA2F@steamermedia.com> Definitely serious. May bring my kids. I have two soldering irons, so could bring to share, if needed, though I'm not sure how good the tip is for fine work. On Dec 6, 2007, at 1:16 AM, Dorkbot DC wrote: > Howdy dorks, > > We need a show of hands to see how many of you are interested in > attending the 16 January 2008, 7-9pm, joint Dorkbot DC + Make: DC > (always FREE, except for materials) workshop meeting at the Marian > Koshland Science Museum of the National Academy of Sciences (@ 5th & > E Sts, NW DC). We'll be building the LED cube: > > http://tinyurl.com/yoddhh > > We're trying to get volume discounts on materialss for the workshop > and it would help to see how much *serious* interest there is out > there. > > What say you? > > Thanks, > > Alberto > > > > ........................................................................ > .......dorkbot dc: people doing strange things with > electricity......... > ................... http://dorkbot.org/ > dorkbotdc ....................... > ........................................................................ From dorkbotdc at dorkbot.org Thu Dec 6 13:07:16 2007 From: dorkbotdc at dorkbot.org (Dorkbot DC) Date: Thu Dec 6 13:07:22 2007 Subject: [dorkbotdc-blabber] Dorkbot DC + Make DC workshop: show of hands In-Reply-To: <8FBCA5F5-C454-4F16-9BD6-9E29F20DDA2F@steamermedia.com> References: <475793CE.8050600@dorkbot.org> <8FBCA5F5-C454-4F16-9BD6-9E29F20DDA2F@steamermedia.com> Message-ID: <47583A54.6000705@dorkbot.org> Thanks, Mark. How many kits is that, then? One? Alberto On 12/6/07 12:47 PM, Mark N. Boszko wrote: > Definitely serious. May bring my kids. I have two soldering irons, so > could bring to share, if needed, though I'm not sure how good the tip is > for fine work. > > On Dec 6, 2007, at 1:16 AM, Dorkbot DC wrote: > >> Howdy dorks, >> >> We need a show of hands to see how many of you are interested in >> attending the 16 January 2008, 7-9pm, joint Dorkbot DC + Make: DC >> (always FREE, except for materials) workshop meeting at the Marian >> Koshland Science Museum of the National Academy of Sciences (@ 5th & E >> Sts, NW DC). We'll be building the LED cube: >> >> http://tinyurl.com/yoddhh >> >> We're trying to get volume discounts on materialss for the workshop >> and it would help to see how much *serious* interest there is out there. >> >> What say you? >> >> Thanks, >> >> Alberto >> >> >> >> ........................................................................ >> .......dorkbot dc: people doing strange things with electricity......... >> ................... http://dorkbot.org/dorkbotdc ....................... >> ........................................................................ > > ........................................................................ > .......dorkbot dc: people doing strange things with electricity......... > ................... http://dorkbot.org/dorkbotdc ....................... > ........................................................................ > From mark at steamermedia.com Thu Dec 6 13:08:52 2007 From: mark at steamermedia.com (Mark N. Boszko) Date: Thu Dec 6 13:09:15 2007 Subject: [dorkbotdc-blabber] Dorkbot DC + Make DC workshop: show of hands In-Reply-To: <47583A54.6000705@dorkbot.org> References: <475793CE.8050600@dorkbot.org> <8FBCA5F5-C454-4F16-9BD6-9E29F20DDA2F@steamermedia.com> <47583A54.6000705@dorkbot.org> Message-ID: Yes, just one, thanks. MB On Dec 6, 2007, at 1:07 PM, Dorkbot DC wrote: > Thanks, Mark. How many kits is that, then? One? > > Alberto > > On 12/6/07 12:47 PM, Mark N. Boszko wrote: >> Definitely serious. May bring my kids. I have two soldering irons, >> so could bring to share, if needed, though I'm not sure how good >> the tip is for fine work. >> On Dec 6, 2007, at 1:16 AM, Dorkbot DC wrote: >>> Howdy dorks, >>> >>> We need a show of hands to see how many of you are interested in >>> attending the 16 January 2008, 7-9pm, joint Dorkbot DC + Make: DC >>> (always FREE, except for materials) workshop meeting at the Marian >>> Koshland Science Museum of the National Academy of Sciences (@ 5th >>> & E Sts, NW DC). We'll be building the LED cube: >>> >>> http://tinyurl.com/yoddhh >>> >>> We're trying to get volume discounts on materialss for the >>> workshop and it would help to see how much *serious* interest >>> there is out there. >>> >>> What say you? >>> >>> Thanks, >>> >>> Alberto >>> >>> >>> >>> ........................................................................ >>> .......dorkbot dc: people doing strange things with >>> electricity......... >>> ................... http://dorkbot.org/ >>> dorkbotdc ....................... >>> ........................................................................ >> ........................................................................ >> .......dorkbot dc: people doing strange things with >> electricity......... >> ................... http://dorkbot.org/ >> dorkbotdc ....................... >> ........................................................................ > ........................................................................ > .......dorkbot dc: people doing strange things with > electricity......... > ................... http://dorkbot.org/ > dorkbotdc ....................... > ........................................................................ From tim at slagle.org Thu Dec 6 14:32:37 2007 From: tim at slagle.org (Tim Slagle) Date: Thu Dec 6 14:32:41 2007 Subject: [dorkbotdc-blabber] Re: LED Cube Workshop In-Reply-To: Message-ID: <300404.3913.qm@web30615.mail.mud.yahoo.com> Sign me up for a kit, but I would probably want it before the meeting so I can put it together in advance. If other people want to do this it will complicate the logistics of a volume order I'm afraid. Also, the circuit that drives the cube is a hack, and probably wouldn't work too well to drive multiple cubes without additional parts. The cube is driven as three multiplexed planes of 3x3=9 LEDs. The LEDs in a plane are driven directly from the AVR uC pins, which is okay, since they can drive about 25mA. But then the planes are addressed by pulling the current from the whole 9 LEDs into a single AVR uC pin, which is a lot more current than the AVR can sink. So, the cubes will already be operating at ~1/27th the brightness of a directly driven LED, and adding more cubes in parallel would only make them dimmer. One change that could be easily done to increase brightness is use two AVR pins in parallel to sink current from the planes. I think there are enough extra I/O pins to do this for the 3x3x3 cube. The firmware would then have to be changed to set two bits instead of one to address the planes, but this should not be a big deal. A better approach would be to drive the planes through a transistor that could sink more current. This would require soldering three ~1Kohm resistors and 2N3904 or 2N2222 NPN transistors to the plane drive I/O pins, and inverting the bit values of the pins in the firmware. I would recommend making the LED cubes on a piece of perf board if possible, so there would be room to wire up the drive transistors on the board and you wouldn't have to solder them directly to the POV kit. But then, I think like an engineer :-) Mark, if you make the LED grid assembly fixtures, space the LEDs at some multiple of 0.1" so they will fit on a perfboard. They need to be less than 1" apart so I'd say make them 0.7" or so. One variation I've been thinking about that would be cool (but require more firmware changes) would be to use bi-color LEDs. As long as the drive voltage is kept around 3V and two-pin reverse-connected LEDs are used, they could just be wired up like the single-color cube. Then in the software, the I/O pins for inactive planes are set to be high-impedance inputs so no current will flow, and the active plane is set high to address one color and low to address the other color. So the matrix would be scanned like six planes of 3x3 with only one color on at a time. The plane bit values for the high-level addressed color would have to be inverted since they are now active low. I will try to buy some bipolar bi-color LEDs for my own use but others may want them as well... --Tim --- adam koeppel wrote: > Yeah, if this works out well, it could be an installation > worthy > piece. I definitely think the working towards a massive > assembly > approach is a good idea, and it will solve the shortage of POV > kit > problem. We should probably do a little design work ahead of > time to > make sure a single POV kit can provide the power we need, > although I > don't imagine it will be a problem. I'd just hate for it not > to work > because of a power shortage. What do you guys think? > > > > On 12/6/07, Alberto Gait?n wrote: > > Yes! I like the idea of divving up the work factory-style! > ...some folks > > building cubes, and others POV thingies. And the idea for a > > mega-LED-cube is genius enough to stop traffic for hours in > Boston! > > > > A > > > > > > > > On 12/6/07 11:33 AM, R. Mark Adams, Ph.D. wrote: > > > I think this sounds great- if we follow the 'sewing > circle' approach, > > > people are certain to feel like they had an enjoyable > time, as well as > > > (potentially) making something interesting. I would > suggest that we buy > > > and build at least a couple of POV kits in advance, so > people who finish > > > their cubes could hook them up and get so see what they > look like working. > > > in fact, if we encourage the group to work together > collectively, we > > > could set it up so that folks are each working on parts > that can all come > > > together in the end to have something working. > mega-LED-cube, anyone? :-) > > > > > > I am happy to volunteer to buy a couple of kits/LEDs to do > some > > > pre-building if people would like. I can also knock off > some wooden jigs > > > to aid in the LED cube construction. (I can use the robot > I showed last > > > time to make them- cool!) > > > > > > I also have some tool kits and soldering irons that > tool-less folks can > > > use at the meeting if they want. > > > > > > Thanks! > > > Mark > > > > > > Gareth Branwyn wrote: > > >> Hey Everybody, > > >> > > >> As I'm sure you all know, we need to step on it to get > the LED Cube > > >> workshop in gear. > > >> > > >> I talked to Dan Woods at the Maker Store and it's not > firm yet, but > > >> it sounds like they'lll sell us the MiniPOV kits for cost > in exchange > > >> for a "Sponsored by MAKE" and a link on their website, in > the > > >> announcements, etc. The problem is that, given the > season, the kits > > >> are in short supply. He said supply should free up after > Xmas, so > > >> hopefully they could have them to us in early January. > > >> > > >> Tim Slagle said that he could get the LEDs themselves. > Katie Bechtold > > >> and Mark Adams have also volunteered to help. (all copied > in here) > > >> > > >> Alberto said that he'll draft the announcement that > Koshland needs to > > >> see, sooner than later. I'll also help in editing that. > > >> > > >> So, we need to figure out ASAP how we're going to run > this thing. > > >> Personally, I'm not that concerned about whether the > cubes are > > >> finished by the end of the workshop or not. To me, these > things are > > >> more like a sewing circle than anything else, a chance to > socialize, > > >> geek out, learn a skill and a few tips from those more > experienced, > > >> etc. But others might have a different take. > > >> > > >> Given the "shortage" of POV kits, we may have trouble > getting a lot, > > >> if say, 25 or more people each wanted a kit. One thing we > could do is > > >> also approach Lady Ada, the maker, and see if she'd give > us a > > >> discount. Even if she didn't, we could buy them full > price from her > > >> (at $17.50 ea) and spread out the cost over all the kits > we offered > > >> to people. > > >> > > >> So, we need to get a show of hands ASAP for how many > people plan to > > >> purchase a kit. And for one thing, we should insist that > you have to > > >> be participating in the workshop to get the kit at the > discounted price. > > >> > > >> Gareth > > >> > > >> > > > > > > > > > From tim at slagle.org Thu Dec 6 16:07:15 2007 From: tim at slagle.org (Tim Slagle) Date: Thu Dec 6 16:07:21 2007 Subject: [dorkbotdc-blabber] Re: LED Cube Workshop - use an Arduino? In-Reply-To: Message-ID: <586674.56759.qm@web30601.mail.mud.yahoo.com> Thanks for the offer, but now that I think of it I have some AVR prototyping boards that could be used instead of the MiniPOV kit for my experimental purposes. This may complicate things even more, but instead of using hacking the MiniPOV kit the LED cube could be driven from an Arduino. Someone would just have to convert the software from WinAVR C to Arduino's Java-style code. Then commercial Arduinos could be bought, or kits could be made. If people bought assembled Arduinos they could focus on making the LED cube at the meeting. And their Arduino could be the basis of future Make:DC projects as well. I would tentatively volunteer to do the software conversion but if there is someone else with more confirmed free time it might be better. The Make: 3D cube C code could also just be burned into the Arduino CPU (blowing away the bootloader etc) as a backup plan. --Tim --- adam koeppel wrote: > Hi Tim, > > I ordered a POV kit earlier to play around with. I figured it > would > not supply enough currents for a massive array. Your > transistor > solution should work fine. If you want to play around with > any of > your ideas prior to the meeting, I will let you know when I > have > assembled the kit. I would be happy to share it as a > "testing" unit > so we don't have to complicate the group order. > > Cheers, > > Adam > > > On 12/6/07, Tim Slagle wrote: > > Sign me up for a kit, but I would probably want it before > the > > meeting so I can put it together in advance. If other > people > > want to do this it will complicate the logistics of a volume > > order I'm afraid. > > > > Also, the circuit that drives the cube is a hack, and > probably > > wouldn't work too well to drive multiple cubes without > > additional parts. The cube is driven as three multiplexed > > planes of 3x3=9 LEDs. The LEDs in a plane are driven > directly > > from the AVR uC pins, which is okay, since they can drive > about > > 25mA. But then the planes are addressed by pulling the > current > > from the whole 9 LEDs into a single AVR uC pin, which is a > lot > > more current than the AVR can sink. So, the cubes will > already > > be operating at ~1/27th the brightness of a directly driven > LED, > > and adding more cubes in parallel would only make them > dimmer. > > > > One change that could be easily done to increase brightness > is > > use two AVR pins in parallel to sink current from the > planes. I > > think there are enough extra I/O pins to do this for the > 3x3x3 > > cube. The firmware would then have to be changed to set two > > bits instead of one to address the planes, but this should > not > > be a big deal. > > > > A better approach would be to drive the planes through a > > transistor that could sink more current. This would require > > soldering three ~1Kohm resistors and 2N3904 or 2N2222 NPN > > transistors to the plane drive I/O pins, and inverting the > bit > > values of the pins in the firmware. > > > > I would recommend making the LED cubes on a piece of perf > board > > if possible, so there would be room to wire up the drive > > transistors on the board and you wouldn't have to solder > them > > directly to the POV kit. But then, I think like an engineer > :-) > > > > Mark, if you make the LED grid assembly fixtures, space the > LEDs > > at some multiple of 0.1" so they will fit on a perfboard. > They > > need to be less than 1" apart so I'd say make them 0.7" or > so. > > > > One variation I've been thinking about that would be cool > (but > > require more firmware changes) would be to use bi-color > LEDs. > > As long as the drive voltage is kept around 3V and two-pin > > reverse-connected LEDs are used, they could just be wired up > > like the single-color cube. Then in the software, the I/O > pins > > for inactive planes are set to be high-impedance inputs so > no > > current will flow, and the active plane is set high to > address > > one color and low to address the other color. So the matrix > > would be scanned like six planes of 3x3 with only one color > on > > at a time. The plane bit values for the high-level > addressed > > color would have to be inverted since they are now active > low. > > > > I will try to buy some bipolar bi-color LEDs for my own use > but > > others may want them as well... > > --Tim > > > > > > > > > > > > --- adam koeppel wrote: > > > > > Yeah, if this works out well, it could be an installation > > > worthy > > > piece. I definitely think the working towards a massive > > > assembly > > > approach is a good idea, and it will solve the shortage of > POV > > > kit > > > problem. We should probably do a little design work ahead > of > > > time to > > > make sure a single POV kit can provide the power we need, > > > although I > > > don't imagine it will be a problem. I'd just hate for it > not > > > to work > > > because of a power shortage. What do you guys think? > > > > > > > > > > > > On 12/6/07, Alberto Gait?n > wrote: > > > > Yes! I like the idea of divving up the work > factory-style! > > > ...some folks > > > > building cubes, and others POV thingies. And the idea > for a > > > > mega-LED-cube is genius enough to stop traffic for hours > in > > > Boston! > > > > > > > > A > > > > > > > > > > > > > > > > On 12/6/07 11:33 AM, R. Mark Adams, Ph.D. wrote: > > > > > I think this sounds great- if we follow the 'sewing > > > circle' approach, > > > > > people are certain to feel like they had an enjoyable > > > time, as well as > > > > > (potentially) making something interesting. I would > > > suggest that we buy > > > > > and build at least a couple of POV kits in advance, so > > > people who finish > > > > > their cubes could hook them up and get so see what > they > > > look like working. > > > > > in fact, if we encourage the group to work together > > > collectively, we > > > > > could set it up so that folks are each working on > parts > > > that can all come > > > > > together in the end to have something working. > > > mega-LED-cube, anyone? :-) > > > > > > > > > > I am happy to volunteer to buy a couple of kits/LEDs > to do > > > some > > > > > pre-building if people would like. I can also knock > off > > > some wooden jigs > > > > > to aid in the LED cube construction. (I can use the > robot > > > I showed last > > > > > time to make them- cool!) > > > > > > > > > > I also have some tool kits and soldering irons that > > > tool-less folks can > > > > > use at the meeting if they want. > > > > > > > > > > Thanks! > > > > > Mark > > > > > > > > > > Gareth Branwyn wrote: > > > > >> Hey Everybody, > > > > >> > > > > >> As I'm sure you all know, we need to step on it to > get > > > the LED Cube > > > > >> workshop in gear. > > > > >> > > > > >> I talked to Dan Woods at the Maker Store and it's not > > > firm yet, but > > > > >> it sounds like they'lll sell us the MiniPOV kits for > cost > > > in exchange > > > > >> for a "Sponsored by MAKE" and a link on their > website, in > > > the > > > > >> announcements, etc. The problem is that, given the > > > season, the kits > > > > >> are in short supply. He said supply should free up > after > > > Xmas, so > > > > >> hopefully they could have them to us in early > January. > > > > >> > > > > >> Tim Slagle said that he could get the LEDs > themselves. > > > Katie Bechtold > > > > >> and Mark Adams have also volunteered to help. (all > copied > > > in here) > > > > >> > > > > >> Alberto said that he'll draft the announcement that > > > Koshland needs to > > > > >> see, sooner than later. I'll also help in editing > that. > > > > >> > > > > >> So, we need to figure out ASAP how we're going to run > > > this thing. > > > > >> Personally, I'm not that concerned about whether the > > > cubes are > > > > >> finished by the end of the workshop or not. To me, > these > > > things are > > > > >> more like a sewing circle than anything else, a > chance to > > > socialize, > > > > >> geek out, learn a skill and a few tips from those > more > > > experienced, > > > > >> etc. But others might have a different take. > > > > >> > > > > >> Given the "shortage" of POV kits, we may have trouble > > > getting a lot, > > > > >> if say, 25 or more people each wanted a kit. One > thing we > > > could do is > > > > >> also approach Lady Ada, the maker, and see if she'd > give > > > us a > > > > >> discount. Even if she didn't, we could buy them full > > > price from her > > > > >> (at $17.50 ea) and spread out the cost over all the > kits > > > we offered > > > > >> to people. > > > > >> > > > > >> So, we need to get a show of hands ASAP for how many > > > people plan to > > > > >> purchase a kit. And for one thing, we should insist > that > > > you have to > > > > >> be participating in the workshop to get the kit at > the > > > discounted price. > > > > >> > > > > >> Gareth > > > > >> > > > > >> > > > > > > > > > > > > > > > > > > > > > > From alberto.gaitan at gmail.com Thu Dec 6 16:35:04 2007 From: alberto.gaitan at gmail.com (=?ISO-8859-1?Q?Alberto_Gait=E1n?=) Date: Thu Dec 6 16:35:57 2007 Subject: [dorkbotdc-blabber] Re: LED Cube Workshop - use an Arduino? In-Reply-To: <586674.56759.qm@web30601.mail.mud.yahoo.com> References: <586674.56759.qm@web30601.mail.mud.yahoo.com> Message-ID: <47586B08.6030800@gmail.com> This is a great idea. Especially because everk self-respecting maker needs an Arduino. I'm pretty sure I don't have the time for this conversion. If none of you do, either, perhaps we can recruit someone else from the greater list? The Arduino uses Processing as its language and it's pretty well documented. Haven't looked at the WinAVR C code and don't know how many lines o'code it has but someone with some chops could make short shrift of it. Can't be too long. Anyone else have the time to do this? Alberto On 12/6/07 4:07 PM, Tim Slagle wrote: > Thanks for the offer, but now that I think of it I have some AVR > prototyping boards that could be used instead of the MiniPOV kit > for my experimental purposes. > > This may complicate things even more, but instead of using > hacking the MiniPOV kit the LED cube could be driven from an > Arduino. Someone would just have to convert the software from > WinAVR C to Arduino's Java-style code. Then commercial Arduinos > could be bought, or kits could be made. If people bought > assembled Arduinos they could focus on making the LED cube at > the meeting. And their Arduino could be the basis of future > Make:DC projects as well. > > I would tentatively volunteer to do the software conversion but > if there is someone else with more confirmed free time it might > be better. The Make: 3D cube C code could also just be burned > into the Arduino CPU (blowing away the bootloader etc) as a > backup plan. > --Tim > > > > --- adam koeppel wrote: > >> Hi Tim, >> >> I ordered a POV kit earlier to play around with. I figured it >> would >> not supply enough currents for a massive array. Your >> transistor >> solution should work fine. If you want to play around with >> any of >> your ideas prior to the meeting, I will let you know when I >> have >> assembled the kit. I would be happy to share it as a >> "testing" unit >> so we don't have to complicate the group order. >> >> Cheers, >> >> Adam >> >> >> On 12/6/07, Tim Slagle wrote: >>> Sign me up for a kit, but I would probably want it before >> the >>> meeting so I can put it together in advance. If other >> people >>> want to do this it will complicate the logistics of a volume >>> order I'm afraid. >>> >>> Also, the circuit that drives the cube is a hack, and >> probably >>> wouldn't work too well to drive multiple cubes without >>> additional parts. The cube is driven as three multiplexed >>> planes of 3x3=9 LEDs. The LEDs in a plane are driven >> directly >>> from the AVR uC pins, which is okay, since they can drive >> about >>> 25mA. But then the planes are addressed by pulling the >> current >>> from the whole 9 LEDs into a single AVR uC pin, which is a >> lot >>> more current than the AVR can sink. So, the cubes will >> already >>> be operating at ~1/27th the brightness of a directly driven >> LED, >>> and adding more cubes in parallel would only make them >> dimmer. >>> One change that could be easily done to increase brightness >> is >>> use two AVR pins in parallel to sink current from the >> planes. I >>> think there are enough extra I/O pins to do this for the >> 3x3x3 >>> cube. The firmware would then have to be changed to set two >>> bits instead of one to address the planes, but this should >> not >>> be a big deal. >>> >>> A better approach would be to drive the planes through a >>> transistor that could sink more current. This would require >>> soldering three ~1Kohm resistors and 2N3904 or 2N2222 NPN >>> transistors to the plane drive I/O pins, and inverting the >> bit >>> values of the pins in the firmware. >>> >>> I would recommend making the LED cubes on a piece of perf >> board >>> if possible, so there would be room to wire up the drive >>> transistors on the board and you wouldn't have to solder >> them >>> directly to the POV kit. But then, I think like an engineer >> :-) >>> Mark, if you make the LED grid assembly fixtures, space the >> LEDs >>> at some multiple of 0.1" so they will fit on a perfboard. >> They >>> need to be less than 1" apart so I'd say make them 0.7" or >> so. >>> One variation I've been thinking about that would be cool >> (but >>> require more firmware changes) would be to use bi-color >> LEDs. >>> As long as the drive voltage is kept around 3V and two-pin >>> reverse-connected LEDs are used, they could just be wired up >>> like the single-color cube. Then in the software, the I/O >> pins >>> for inactive planes are set to be high-impedance inputs so >> no >>> current will flow, and the active plane is set high to >> address >>> one color and low to address the other color. So the matrix >>> would be scanned like six planes of 3x3 with only one color >> on >>> at a time. The plane bit values for the high-level >> addressed >>> color would have to be inverted since they are now active >> low. >>> I will try to buy some bipolar bi-color LEDs for my own use >> but >>> others may want them as well... >>> --Tim >>> >>> >>> >>> >>> >>> --- adam koeppel wrote: >>> >>>> Yeah, if this works out well, it could be an installation >>>> worthy >>>> piece. I definitely think the working towards a massive >>>> assembly >>>> approach is a good idea, and it will solve the shortage of >> POV >>>> kit >>>> problem. We should probably do a little design work ahead >> of >>>> time to >>>> make sure a single POV kit can provide the power we need, >>>> although I >>>> don't imagine it will be a problem. I'd just hate for it >> not >>>> to work >>>> because of a power shortage. What do you guys think? >>>> >>>> >>>> >>>> On 12/6/07, Alberto Gait?n >> wrote: >>>>> Yes! I like the idea of divving up the work >> factory-style! >>>> ...some folks >>>>> building cubes, and others POV thingies. And the idea >> for a >>>>> mega-LED-cube is genius enough to stop traffic for hours >> in >>>> Boston! >>>>> A >>>>> >>>>> >>>>> >>>>> On 12/6/07 11:33 AM, R. Mark Adams, Ph.D. wrote: >>>>>> I think this sounds great- if we follow the 'sewing >>>> circle' approach, >>>>>> people are certain to feel like they had an enjoyable >>>> time, as well as >>>>>> (potentially) making something interesting. I would >>>> suggest that we buy >>>>>> and build at least a couple of POV kits in advance, so >>>> people who finish >>>>>> their cubes could hook them up and get so see what >> they >>>> look like working. >>>>>> in fact, if we encourage the group to work together >>>> collectively, we >>>>>> could set it up so that folks are each working on >> parts >>>> that can all come >>>>>> together in the end to have something working. >>>> mega-LED-cube, anyone? :-) >>>>>> I am happy to volunteer to buy a couple of kits/LEDs >> to do >>>> some >>>>>> pre-building if people would like. I can also knock >> off >>>> some wooden jigs >>>>>> to aid in the LED cube construction. (I can use the >> robot >>>> I showed last >>>>>> time to make them- cool!) >>>>>> >>>>>> I also have some tool kits and soldering irons that >>>> tool-less folks can >>>>>> use at the meeting if they want. >>>>>> >>>>>> Thanks! >>>>>> Mark >>>>>> >>>>>> Gareth Branwyn wrote: >>>>>>> Hey Everybody, >>>>>>> >>>>>>> As I'm sure you all know, we need to step on it to >> get >>>> the LED Cube >>>>>>> workshop in gear. >>>>>>> >>>>>>> I talked to Dan Woods at the Maker Store and it's not >>>> firm yet, but >>>>>>> it sounds like they'lll sell us the MiniPOV kits for >> cost >>>> in exchange >>>>>>> for a "Sponsored by MAKE" and a link on their >> website, in >>>> the >>>>>>> announcements, etc. The problem is that, given the >>>> season, the kits >>>>>>> are in short supply. He said supply should free up >> after >>>> Xmas, so >>>>>>> hopefully they could have them to us in early >> January. >>>>>>> Tim Slagle said that he could get the LEDs >> themselves. >>>> Katie Bechtold >>>>>>> and Mark Adams have also volunteered to help. (all >> copied >>>> in here) >>>>>>> Alberto said that he'll draft the announcement that >>>> Koshland needs to >>>>>>> see, sooner than later. I'll also help in editing >> that. >>>>>>> So, we need to figure out ASAP how we're going to run >>>> this thing. >>>>>>> Personally, I'm not that concerned about whether the >>>> cubes are >>>>>>> finished by the end of the workshop or not. To me, >> these >>>> things are >>>>>>> more like a sewing circle than anything else, a >> chance to >>>> socialize, >>>>>>> geek out, learn a skill and a few tips from those >> more >>>> experienced, >>>>>>> etc. But others might have a different take. >>>>>>> >>>>>>> Given the "shortage" of POV kits, we may have trouble >>>> getting a lot, >>>>>>> if say, 25 or more people each wanted a kit. One >> thing we >>>> could do is >>>>>>> also approach Lady Ada, the maker, and see if she'd >> give >>>> us a >>>>>>> discount. Even if she didn't, we could buy them full >>>> price from her >>>>>>> (at $17.50 ea) and spread out the cost over all the >> kits >>>> we offered >>>>>>> to people. >>>>>>> >>>>>>> So, we need to get a show of hands ASAP for how many >>>> people plan to >>>>>>> purchase a kit. And for one thing, we should insist >> that >>>> you have to >>>>>>> be participating in the workshop to get the kit at >> the >>>> discounted price. >>>>>>> Gareth >>>>>>> >>>>>>> >>>>>> >>> > > From koeppel at gmail.com Thu Dec 6 16:41:35 2007 From: koeppel at gmail.com (adam koeppel) Date: Thu Dec 6 16:42:50 2007 Subject: [dorkbotdc-blabber] Re: LED Cube Workshop - use an Arduino? In-Reply-To: <47586B08.6030800@gmail.com> References: <586674.56759.qm@web30601.mail.mud.yahoo.com> <47586B08.6030800@gmail.com> Message-ID: I probably have time, but maybe not the skill. Also, MAKE store is currently out of Arduinos... Damn holiday season... I love the idea of everyone having an Arduino for this and future projects. On 12/6/07, Alberto Gait?n wrote: > This is a great idea. Especially because everk self-respecting maker > needs an Arduino. I'm pretty sure I don't have the time for this > conversion. If none of you do, either, perhaps we can recruit someone > else from the greater list? > > The Arduino uses Processing as its language and it's pretty well > documented. Haven't looked at the WinAVR C code and don't know how many > lines o'code it has but someone with some chops could make short shrift > of it. Can't be too long. > > Anyone else have the time to do this? > > Alberto > > > > On 12/6/07 4:07 PM, Tim Slagle wrote: > > Thanks for the offer, but now that I think of it I have some AVR > > prototyping boards that could be used instead of the MiniPOV kit > > for my experimental purposes. > > > > This may complicate things even more, but instead of using > > hacking the MiniPOV kit the LED cube could be driven from an > > Arduino. Someone would just have to convert the software from > > WinAVR C to Arduino's Java-style code. Then commercial Arduinos > > could be bought, or kits could be made. If people bought > > assembled Arduinos they could focus on making the LED cube at > > the meeting. And their Arduino could be the basis of future > > Make:DC projects as well. > > > > I would tentatively volunteer to do the software conversion but > > if there is someone else with more confirmed free time it might > > be better. The Make: 3D cube C code could also just be burned > > into the Arduino CPU (blowing away the bootloader etc) as a > > backup plan. > > --Tim > > > > > > > > --- adam koeppel wrote: > > > >> Hi Tim, > >> > >> I ordered a POV kit earlier to play around with. I figured it > >> would > >> not supply enough currents for a massive array. Your > >> transistor > >> solution should work fine. If you want to play around with > >> any of > >> your ideas prior to the meeting, I will let you know when I > >> have > >> assembled the kit. I would be happy to share it as a > >> "testing" unit > >> so we don't have to complicate the group order. > >> > >> Cheers, > >> > >> Adam > >> > >> > >> On 12/6/07, Tim Slagle wrote: > >>> Sign me up for a kit, but I would probably want it before > >> the > >>> meeting so I can put it together in advance. If other > >> people > >>> want to do this it will complicate the logistics of a volume > >>> order I'm afraid. > >>> > >>> Also, the circuit that drives the cube is a hack, and > >> probably > >>> wouldn't work too well to drive multiple cubes without > >>> additional parts. The cube is driven as three multiplexed > >>> planes of 3x3=9 LEDs. The LEDs in a plane are driven > >> directly > >>> from the AVR uC pins, which is okay, since they can drive > >> about > >>> 25mA. But then the planes are addressed by pulling the > >> current > >>> from the whole 9 LEDs into a single AVR uC pin, which is a > >> lot > >>> more current than the AVR can sink. So, the cubes will > >> already > >>> be operating at ~1/27th the brightness of a directly driven > >> LED, > >>> and adding more cubes in parallel would only make them > >> dimmer. > >>> One change that could be easily done to increase brightness > >> is > >>> use two AVR pins in parallel to sink current from the > >> planes. I > >>> think there are enough extra I/O pins to do this for the > >> 3x3x3 > >>> cube. The firmware would then have to be changed to set two > >>> bits instead of one to address the planes, but this should > >> not > >>> be a big deal. > >>> > >>> A better approach would be to drive the planes through a > >>> transistor that could sink more current. This would require > >>> soldering three ~1Kohm resistors and 2N3904 or 2N2222 NPN > >>> transistors to the plane drive I/O pins, and inverting the > >> bit > >>> values of the pins in the firmware. > >>> > >>> I would recommend making the LED cubes on a piece of perf > >> board > >>> if possible, so there would be room to wire up the drive > >>> transistors on the board and you wouldn't have to solder > >> them > >>> directly to the POV kit. But then, I think like an engineer > >> :-) > >>> Mark, if you make the LED grid assembly fixtures, space the > >> LEDs > >>> at some multiple of 0.1" so they will fit on a perfboard. > >> They > >>> need to be less than 1" apart so I'd say make them 0.7" or > >> so. > >>> One variation I've been thinking about that would be cool > >> (but > >>> require more firmware changes) would be to use bi-color > >> LEDs. > >>> As long as the drive voltage is kept around 3V and two-pin > >>> reverse-connected LEDs are used, they could just be wired up > >>> like the single-color cube. Then in the software, the I/O > >> pins > >>> for inactive planes are set to be high-impedance inputs so > >> no > >>> current will flow, and the active plane is set high to > >> address > >>> one color and low to address the other color. So the matrix > >>> would be scanned like six planes of 3x3 with only one color > >> on > >>> at a time. The plane bit values for the high-level > >> addressed > >>> color would have to be inverted since they are now active > >> low. > >>> I will try to buy some bipolar bi-color LEDs for my own use > >> but > >>> others may want them as well... > >>> --Tim > >>> > >>> > >>> > >>> > >>> > >>> --- adam koeppel wrote: > >>> > >>>> Yeah, if this works out well, it could be an installation > >>>> worthy > >>>> piece. I definitely think the working towards a massive > >>>> assembly > >>>> approach is a good idea, and it will solve the shortage of > >> POV > >>>> kit > >>>> problem. We should probably do a little design work ahead > >> of > >>>> time to > >>>> make sure a single POV kit can provide the power we need, > >>>> although I > >>>> don't imagine it will be a problem. I'd just hate for it > >> not > >>>> to work > >>>> because of a power shortage. What do you guys think? > >>>> > >>>> > >>>> > >>>> On 12/6/07, Alberto Gait?n > >> wrote: > >>>>> Yes! I like the idea of divving up the work > >> factory-style! > >>>> ...some folks > >>>>> building cubes, and others POV thingies. And the idea > >> for a > >>>>> mega-LED-cube is genius enough to stop traffic for hours > >> in > >>>> Boston! > >>>>> A > >>>>> > >>>>> > >>>>> > >>>>> On 12/6/07 11:33 AM, R. Mark Adams, Ph.D. wrote: > >>>>>> I think this sounds great- if we follow the 'sewing > >>>> circle' approach, > >>>>>> people are certain to feel like they had an enjoyable > >>>> time, as well as > >>>>>> (potentially) making something interesting. I would > >>>> suggest that we buy > >>>>>> and build at least a couple of POV kits in advance, so > >>>> people who finish > >>>>>> their cubes could hook them up and get so see what > >> they > >>>> look like working. > >>>>>> in fact, if we encourage the group to work together > >>>> collectively, we > >>>>>> could set it up so that folks are each working on > >> parts > >>>> that can all come > >>>>>> together in the end to have something working. > >>>> mega-LED-cube, anyone? :-) > >>>>>> I am happy to volunteer to buy a couple of kits/LEDs > >> to do > >>>> some > >>>>>> pre-building if people would like. I can also knock > >> off > >>>> some wooden jigs > >>>>>> to aid in the LED cube construction. (I can use the > >> robot > >>>> I showed last > >>>>>> time to make them- cool!) > >>>>>> > >>>>>> I also have some tool kits and soldering irons that > >>>> tool-less folks can > >>>>>> use at the meeting if they want. > >>>>>> > >>>>>> Thanks! > >>>>>> Mark > >>>>>> > >>>>>> Gareth Branwyn wrote: > >>>>>>> Hey Everybody, > >>>>>>> > >>>>>>> As I'm sure you all know, we need to step on it to > >> get > >>>> the LED Cube > >>>>>>> workshop in gear. > >>>>>>> > >>>>>>> I talked to Dan Woods at the Maker Store and it's not > >>>> firm yet, but > >>>>>>> it sounds like they'lll sell us the MiniPOV kits for > >> cost > >>>> in exchange > >>>>>>> for a "Sponsored by MAKE" and a link on their > >> website, in > >>>> the > >>>>>>> announcements, etc. The problem is that, given the > >>>> season, the kits > >>>>>>> are in short supply. He said supply should free up > >> after > >>>> Xmas, so > >>>>>>> hopefully they could have them to us in early > >> January. > >>>>>>> Tim Slagle said that he could get the LEDs > >> themselves. > >>>> Katie Bechtold > >>>>>>> and Mark Adams have also volunteered to help. (all > >> copied > >>>> in here) > >>>>>>> Alberto said that he'll draft the announcement that > >>>> Koshland needs to > >>>>>>> see, sooner than later. I'll also help in editing > >> that. > >>>>>>> So, we need to figure out ASAP how we're going to run > >>>> this thing. > >>>>>>> Personally, I'm not that concerned about whether the > >>>> cubes are > >>>>>>> finished by the end of the workshop or not. To me, > >> these > >>>> things are > >>>>>>> more like a sewing circle than anything else, a > >> chance to > >>>> socialize, > >>>>>>> geek out, learn a skill and a few tips from those > >> more > >>>> experienced, > >>>>>>> etc. But others might have a different take. > >>>>>>> > >>>>>>> Given the "shortage" of POV kits, we may have trouble > >>>> getting a lot, > >>>>>>> if say, 25 or more people each wanted a kit. One > >> thing we > >>>> could do is > >>>>>>> also approach Lady Ada, the maker, and see if she'd > >> give > >>>> us a > >>>>>>> discount. Even if she didn't, we could buy them full > >>>> price from her > >>>>>>> (at $17.50 ea) and spread out the cost over all the > >> kits > >>>> we offered > >>>>>>> to people. > >>>>>>> > >>>>>>> So, we need to get a show of hands ASAP for how many > >>>> people plan to > >>>>>>> purchase a kit. And for one thing, we should insist > >> that > >>>> you have to > >>>>>>> be participating in the workshop to get the kit at > >> the > >>>> discounted price. > >>>>>>> Gareth > >>>>>>> > >>>>>>> > >>>>>> > >>> > > > > > From rmadams at epotential.com Thu Dec 6 16:45:25 2007 From: rmadams at epotential.com (R. Mark Adams, Ph.D.) Date: Thu Dec 6 16:45:39 2007 Subject: [dorkbotdc-blabber] Re: LED Cube Workshop In-Reply-To: <300404.3913.qm@web30615.mail.mud.yahoo.com> References: <300404.3913.qm@web30615.mail.mud.yahoo.com> Message-ID: <4909.156.80.125.177.1196977525.squirrel@mail4.webfaction.com> I like the bipolar LED idea! If you want to buy a set to try out, I would be happy to go in on the buy so I can hack around too. I will do the holes at the 0.1 pin-spacing multiple, too. Perhaps we could have the 'cube builders' add the driver transistors at the same time as they build the cube. We would need to amend the plans and test the build in advance. Also- in order to enable the "mega-cube" how about if each cube is wired to shift-register(s) and expose a clock and data line- that way you could either (1) daisy-chain them, or (2) have each cube be driven off of one pin of the microcontroller. I have done something similar for driving LED matrix displays from my embedded computers in the past. THanks! -Mark Tim Slagle wrote: > Sign me up for a kit, but I would probably want it before the > meeting so I can put it together in advance. If other people > want to do this it will complicate the logistics of a volume > order I'm afraid. > > Also, the circuit that drives the cube is a hack, and probably > wouldn't work too well to drive multiple cubes without > additional parts. The cube is driven as three multiplexed > planes of 3x3=9 LEDs. The LEDs in a plane are driven directly > from the AVR uC pins, which is okay, since they can drive about > 25mA. But then the planes are addressed by pulling the current > from the whole 9 LEDs into a single AVR uC pin, which is a lot > more current than the AVR can sink. So, the cubes will already > be operating at ~1/27th the brightness of a directly driven LED, > and adding more cubes in parallel would only make them dimmer. > > One change that could be easily done to increase brightness is > use two AVR pins in parallel to sink current from the planes. I > think there are enough extra I/O pins to do this for the 3x3x3 > cube. The firmware would then have to be changed to set two > bits instead of one to address the planes, but this should not > be a big deal. > > A better approach would be to drive the planes through a > transistor that could sink more current. This would require > soldering three ~1Kohm resistors and 2N3904 or 2N2222 NPN > transistors to the plane drive I/O pins, and inverting the bit > values of the pins in the firmware. > > I would recommend making the LED cubes on a piece of perf board > if possible, so there would be room to wire up the drive > transistors on the board and you wouldn't have to solder them > directly to the POV kit. But then, I think like an engineer :-) > > Mark, if you make the LED grid assembly fixtures, space the LEDs > at some multiple of 0.1" so they will fit on a perfboard. They > need to be less than 1" apart so I'd say make them 0.7" or so. > > One variation I've been thinking about that would be cool (but > require more firmware changes) would be to use bi-color LEDs. > As long as the drive voltage is kept around 3V and two-pin > reverse-connected LEDs are used, they could just be wired up > like the single-color cube. Then in the software, the I/O pins > for inactive planes are set to be high-impedance inputs so no > current will flow, and the active plane is set high to address > one color and low to address the other color. So the matrix > would be scanned like six planes of 3x3 with only one color on > at a time. The plane bit values for the high-level addressed > color would have to be inverted since they are now active low. > > I will try to buy some bipolar bi-color LEDs for my own use but > others may want them as well... > --Tim > > > > > > --- adam koeppel wrote: > >> Yeah, if this works out well, it could be an installation >> worthy >> piece. I definitely think the working towards a massive >> assembly >> approach is a good idea, and it will solve the shortage of POV >> kit >> problem. We should probably do a little design work ahead of >> time to >> make sure a single POV kit can provide the power we need, >> although I >> don't imagine it will be a problem. I'd just hate for it not >> to work >> because of a power shortage. What do you guys think? >> >> >> >> On 12/6/07, Alberto Gait?n wrote: >> > Yes! I like the idea of divving up the work factory-style! >> ...some folks >> > building cubes, and others POV thingies. And the idea for a >> > mega-LED-cube is genius enough to stop traffic for hours in >> Boston! >> > >> > A >> > >> > >> > >> > On 12/6/07 11:33 AM, R. Mark Adams, Ph.D. wrote: >> > > I think this sounds great- if we follow the 'sewing >> circle' approach, >> > > people are certain to feel like they had an enjoyable >> time, as well as >> > > (potentially) making something interesting. I would >> suggest that we buy >> > > and build at least a couple of POV kits in advance, so >> people who finish >> > > their cubes could hook them up and get so see what they >> look like working. >> > > in fact, if we encourage the group to work together >> collectively, we >> > > could set it up so that folks are each working on parts >> that can all come >> > > together in the end to have something working. >> mega-LED-cube, anyone? :-) >> > > >> > > I am happy to volunteer to buy a couple of kits/LEDs to do >> some >> > > pre-building if people would like. I can also knock off >> some wooden jigs >> > > to aid in the LED cube construction. (I can use the robot >> I showed last >> > > time to make them- cool!) >> > > >> > > I also have some tool kits and soldering irons that >> tool-less folks can >> > > use at the meeting if they want. >> > > >> > > Thanks! >> > > Mark >> > > >> > > Gareth Branwyn wrote: >> > >> Hey Everybody, >> > >> >> > >> As I'm sure you all know, we need to step on it to get >> the LED Cube >> > >> workshop in gear. >> > >> >> > >> I talked to Dan Woods at the Maker Store and it's not >> firm yet, but >> > >> it sounds like they'lll sell us the MiniPOV kits for cost >> in exchange >> > >> for a "Sponsored by MAKE" and a link on their website, in >> the >> > >> announcements, etc. The problem is that, given the >> season, the kits >> > >> are in short supply. He said supply should free up after >> Xmas, so >> > >> hopefully they could have them to us in early January. >> > >> >> > >> Tim Slagle said that he could get the LEDs themselves. >> Katie Bechtold >> > >> and Mark Adams have also volunteered to help. (all copied >> in here) >> > >> >> > >> Alberto said that he'll draft the announcement that >> Koshland needs to >> > >> see, sooner than later. I'll also help in editing that. >> > >> >> > >> So, we need to figure out ASAP how we're going to run >> this thing. >> > >> Personally, I'm not that concerned about whether the >> cubes are >> > >> finished by the end of the workshop or not. To me, these >> things are >> > >> more like a sewing circle than anything else, a chance to >> socialize, >> > >> geek out, learn a skill and a few tips from those more >> experienced, >> > >> etc. But others might have a different take. >> > >> >> > >> Given the "shortage" of POV kits, we may have trouble >> getting a lot, >> > >> if say, 25 or more people each wanted a kit. One thing we >> could do is >> > >> also approach Lady Ada, the maker, and see if she'd give >> us a >> > >> discount. Even if she didn't, we could buy them full >> price from her >> > >> (at $17.50 ea) and spread out the cost over all the kits >> we offered >> > >> to people. >> > >> >> > >> So, we need to get a show of hands ASAP for how many >> people plan to >> > >> purchase a kit. And for one thing, we should insist that >> you have to >> > >> be participating in the workshop to get the kit at the >> discounted price. >> > >> >> > >> Gareth >> > >> >> > >> >> > > >> > > >> > >> > > -- | | "Information is light. | | R. Mark Adams, Ph.D. | Information in itself, | | Computational Biologist | about anything, is light." | | rmadams@epotential.com | - Tom Stoppard | From rmadams at epotential.com Thu Dec 6 16:53:06 2007 From: rmadams at epotential.com (R. Mark Adams, Ph.D.) Date: Thu Dec 6 16:53:19 2007 Subject: [dorkbotdc-blabber] Re: LED Cube Workshop - use an Arduino? In-Reply-To: <586674.56759.qm@web30601.mail.mud.yahoo.com> References: <586674.56759.qm@web30601.mail.mud.yahoo.com> Message-ID: <1099.156.80.125.177.1196977986.squirrel@mail4.webfaction.com> Fantastic idea! Plus, the barebones Arduino kit costs about the same as the POV kit, and is way more generally useful, IMHO. I will take a look at the WinAVR code and see what I can come up with. besides, if we wanted to do the "mega-cube" it would be way easier to do it with the code in Processing... -Mark Tim Slagle wrote: > Thanks for the offer, but now that I think of it I have some AVR > prototyping boards that could be used instead of the MiniPOV kit > for my experimental purposes. > > This may complicate things even more, but instead of using > hacking the MiniPOV kit the LED cube could be driven from an > Arduino. Someone would just have to convert the software from > WinAVR C to Arduino's Java-style code. Then commercial Arduinos > could be bought, or kits could be made. If people bought > assembled Arduinos they could focus on making the LED cube at > the meeting. And their Arduino could be the basis of future > Make:DC projects as well. > > I would tentatively volunteer to do the software conversion but > if there is someone else with more confirmed free time it might > be better. The Make: 3D cube C code could also just be burned > into the Arduino CPU (blowing away the bootloader etc) as a > backup plan. > --Tim > > > > --- adam koeppel wrote: > >> Hi Tim, >> >> I ordered a POV kit earlier to play around with. I figured it >> would >> not supply enough currents for a massive array. Your >> transistor >> solution should work fine. If you want to play around with >> any of >> your ideas prior to the meeting, I will let you know when I >> have >> assembled the kit. I would be happy to share it as a >> "testing" unit >> so we don't have to complicate the group order. >> >> Cheers, >> >> Adam >> >> >> On 12/6/07, Tim Slagle wrote: >> > Sign me up for a kit, but I would probably want it before >> the >> > meeting so I can put it together in advance. If other >> people >> > want to do this it will complicate the logistics of a volume >> > order I'm afraid. >> > >> > Also, the circuit that drives the cube is a hack, and >> probably >> > wouldn't work too well to drive multiple cubes without >> > additional parts. The cube is driven as three multiplexed >> > planes of 3x3=9 LEDs. The LEDs in a plane are driven >> directly >> > from the AVR uC pins, which is okay, since they can drive >> about >> > 25mA. But then the planes are addressed by pulling the >> current >> > from the whole 9 LEDs into a single AVR uC pin, which is a >> lot >> > more current than the AVR can sink. So, the cubes will >> already >> > be operating at ~1/27th the brightness of a directly driven >> LED, >> > and adding more cubes in parallel would only make them >> dimmer. >> > >> > One change that could be easily done to increase brightness >> is >> > use two AVR pins in parallel to sink current from the >> planes. I >> > think there are enough extra I/O pins to do this for the >> 3x3x3 >> > cube. The firmware would then have to be changed to set two >> > bits instead of one to address the planes, but this should >> not >> > be a big deal. >> > >> > A better approach would be to drive the planes through a >> > transistor that could sink more current. This would require >> > soldering three ~1Kohm resistors and 2N3904 or 2N2222 NPN >> > transistors to the plane drive I/O pins, and inverting the >> bit >> > values of the pins in the firmware. >> > >> > I would recommend making the LED cubes on a piece of perf >> board >> > if possible, so there would be room to wire up the drive >> > transistors on the board and you wouldn't have to solder >> them >> > directly to the POV kit. But then, I think like an engineer >> :-) >> > >> > Mark, if you make the LED grid assembly fixtures, space the >> LEDs >> > at some multiple of 0.1" so they will fit on a perfboard. >> They >> > need to be less than 1" apart so I'd say make them 0.7" or >> so. >> > >> > One variation I've been thinking about that would be cool >> (but >> > require more firmware changes) would be to use bi-color >> LEDs. >> > As long as the drive voltage is kept around 3V and two-pin >> > reverse-connected LEDs are used, they could just be wired up >> > like the single-color cube. Then in the software, the I/O >> pins >> > for inactive planes are set to be high-impedance inputs so >> no >> > current will flow, and the active plane is set high to >> address >> > one color and low to address the other color. So the matrix >> > would be scanned like six planes of 3x3 with only one color >> on >> > at a time. The plane bit values for the high-level >> addressed >> > color would have to be inverted since they are now active >> low. >> > >> > I will try to buy some bipolar bi-color LEDs for my own use >> but >> > others may want them as well... >> > --Tim >> > >> > >> > >> > >> > >> > --- adam koeppel wrote: >> > >> > > Yeah, if this works out well, it could be an installation >> > > worthy >> > > piece. I definitely think the working towards a massive >> > > assembly >> > > approach is a good idea, and it will solve the shortage of >> POV >> > > kit >> > > problem. We should probably do a little design work ahead >> of >> > > time to >> > > make sure a single POV kit can provide the power we need, >> > > although I >> > > don't imagine it will be a problem. I'd just hate for it >> not >> > > to work >> > > because of a power shortage. What do you guys think? >> > > >> > > >> > > >> > > On 12/6/07, Alberto Gait?n >> wrote: >> > > > Yes! I like the idea of divving up the work >> factory-style! >> > > ...some folks >> > > > building cubes, and others POV thingies. And the idea >> for a >> > > > mega-LED-cube is genius enough to stop traffic for hours >> in >> > > Boston! >> > > > >> > > > A >> > > > >> > > > >> > > > >> > > > On 12/6/07 11:33 AM, R. Mark Adams, Ph.D. wrote: >> > > > > I think this sounds great- if we follow the 'sewing >> > > circle' approach, >> > > > > people are certain to feel like they had an enjoyable >> > > time, as well as >> > > > > (potentially) making something interesting. I would >> > > suggest that we buy >> > > > > and build at least a couple of POV kits in advance, so >> > > people who finish >> > > > > their cubes could hook them up and get so see what >> they >> > > look like working. >> > > > > in fact, if we encourage the group to work together >> > > collectively, we >> > > > > could set it up so that folks are each working on >> parts >> > > that can all come >> > > > > together in the end to have something working. >> > > mega-LED-cube, anyone? :-) >> > > > > >> > > > > I am happy to volunteer to buy a couple of kits/LEDs >> to do >> > > some >> > > > > pre-building if people would like. I can also knock >> off >> > > some wooden jigs >> > > > > to aid in the LED cube construction. (I can use the >> robot >> > > I showed last >> > > > > time to make them- cool!) >> > > > > >> > > > > I also have some tool kits and soldering irons that >> > > tool-less folks can >> > > > > use at the meeting if they want. >> > > > > >> > > > > Thanks! >> > > > > Mark >> > > > > >> > > > > Gareth Branwyn wrote: >> > > > >> Hey Everybody, >> > > > >> >> > > > >> As I'm sure you all know, we need to step on it to >> get >> > > the LED Cube >> > > > >> workshop in gear. >> > > > >> >> > > > >> I talked to Dan Woods at the Maker Store and it's not >> > > firm yet, but >> > > > >> it sounds like they'lll sell us the MiniPOV kits for >> cost >> > > in exchange >> > > > >> for a "Sponsored by MAKE" and a link on their >> website, in >> > > the >> > > > >> announcements, etc. The problem is that, given the >> > > season, the kits >> > > > >> are in short supply. He said supply should free up >> after >> > > Xmas, so >> > > > >> hopefully they could have them to us in early >> January. >> > > > >> >> > > > >> Tim Slagle said that he could get the LEDs >> themselves. >> > > Katie Bechtold >> > > > >> and Mark Adams have also volunteered to help. (all >> copied >> > > in here) >> > > > >> >> > > > >> Alberto said that he'll draft the announcement that >> > > Koshland needs to >> > > > >> see, sooner than later. I'll also help in editing >> that. >> > > > >> >> > > > >> So, we need to figure out ASAP how we're going to run >> > > this thing. >> > > > >> Personally, I'm not that concerned about whether the >> > > cubes are >> > > > >> finished by the end of the workshop or not. To me, >> these >> > > things are >> > > > >> more like a sewing circle than anything else, a >> chance to >> > > socialize, >> > > > >> geek out, learn a skill and a few tips from those >> more >> > > experienced, >> > > > >> etc. But others might have a different take. >> > > > >> >> > > > >> Given the "shortage" of POV kits, we may have trouble >> > > getting a lot, >> > > > >> if say, 25 or more people each wanted a kit. One >> thing we >> > > could do is >> > > > >> also approach Lady Ada, the maker, and see if she'd >> give >> > > us a >> > > > >> discount. Even if she didn't, we could buy them full >> > > price from her >> > > > >> (at $17.50 ea) and spread out the cost over all the >> kits >> > > we offered >> > > > >> to people. >> > > > >> >> > > > >> So, we need to get a show of hands ASAP for how many >> > > people plan to >> > > > >> purchase a kit. And for one thing, we should insist >> that >> > > you have to >> > > > >> be participating in the workshop to get the kit at >> the >> > > discounted price. >> > > > >> >> > > > >> Gareth >> > > > >> >> > > > >> >> > > > > >> > > > > >> > > > >> > > >> > >> > >> > > -- | | "Information is light. | | R. Mark Adams, Ph.D. | Information in itself, | | Computational Biologist | about anything, is light." | | rmadams@epotential.com | - Tom Stoppard | From joseph.darragh at gmail.com Thu Dec 6 16:59:06 2007 From: joseph.darragh at gmail.com (Joseph Darragh) Date: Thu Dec 6 16:59:11 2007 Subject: [dorkbotdc-blabber] Re: LED Cube Workshop - use an Arduino? (joey darragh) Message-ID: <62259e770712061359o3cf61569m2cf59bfec9674788@mail.gmail.com> Adam- the MAKE store may be out of Arduinos but Adafruit has plenty of them (290 to be exact). Get 'em while the gettin's good! http://www.adafruit.com/index.php?main_page=product_info&cPath=17&products_id=50 -Joey -------------- next part -------------- An HTML attachment was scrubbed... URL: http://music.columbia.edu/pipermail/dorkbotdc-blabber/attachments/20071206/dd83edd9/attachment.html From jaronson at verizon.net Thu Dec 6 17:01:37 2007 From: jaronson at verizon.net (Jesse Aronson) Date: Thu Dec 6 17:02:02 2007 Subject: [dorkbotdc-blabber] re: Dorkbot DC + Make DC workshop: show of hands (M@) In-Reply-To: <20071206145352.C764C4E4158D@music.columbia.edu> References: <20071206145352.C764C4E4158D@music.columbia.edu> Message-ID: <47587141.5010105@verizon.net> I've been a lurker on the list for a while. For the new year I think I'll jump in & come on down. Put me down for a kit. Jesse > 5. Re: Dorkbot DC + Make DC workshop: show of hands (M@) > From tim at slagle.org Thu Dec 6 17:03:29 2007 From: tim at slagle.org (Tim Slagle) Date: Thu Dec 6 17:03:33 2007 Subject: [dorkbotdc-blabber] Re: LED Cube Workshop - use an Arduino? In-Reply-To: Message-ID: <762301.75297.qm@web30601.mail.mud.yahoo.com> I know you would want to use Make: stuff when possible but there are hundreds of Arduinos in stock at AdaFruit: http://www.adafruit.com/index.php?main_page=index&cPath=17 SparcFun also has them: http://www.sparkfun.com/commerce/product_info.php?products_id=666 I think the AdaFruit BoArduino would be the thing to use however, then the transistor drive circuits and LED column connections can just be plugged in to the protoboard without soldering: http://www.adafruit.com/index.php?main_page=product_info&cPath=19&products_id=72 Lots of those in stock also, but they are sold as kits and would need to be soldered up. No harder than building a MiniPOV kit and more useful in the future... --Tim --- adam koeppel wrote: > I probably have time, but maybe not the skill. Also, MAKE > store is > currently out of Arduinos... Damn holiday season... I love > the idea > of everyone having an Arduino for this and future projects. > > On 12/6/07, Alberto Gait?n wrote: > > This is a great idea. Especially because everk > self-respecting maker > > needs an Arduino. I'm pretty sure I don't have the time for > this > > conversion. If none of you do, either, perhaps we can > recruit someone > > else from the greater list? > > > > The Arduino uses Processing as its language and it's pretty > well > > documented. Haven't looked at the WinAVR C code and don't > know how many > > lines o'code it has but someone with some chops could make > short shrift > > of it. Can't be too long. > > > > Anyone else have the time to do this? > > > > Alberto > > > > > > > > On 12/6/07 4:07 PM, Tim Slagle wrote: > > > Thanks for the offer, but now that I think of it I have > some AVR > > > prototyping boards that could be used instead of the > MiniPOV kit > > > for my experimental purposes. > > > > > > This may complicate things even more, but instead of using > > > hacking the MiniPOV kit the LED cube could be driven from > an > > > Arduino. Someone would just have to convert the software > from > > > WinAVR C to Arduino's Java-style code. Then commercial > Arduinos > > > could be bought, or kits could be made. If people > bought > > > assembled Arduinos they could focus on making the LED cube > at > > > the meeting. And their Arduino could be the basis of > future > > > Make:DC projects as well. > > > > > > I would tentatively volunteer to do the software > conversion but > > > if there is someone else with more confirmed free time it > might > > > be better. The Make: 3D cube C code could also just be > burned > > > into the Arduino CPU (blowing away the bootloader etc) as > a > > > backup plan. > > > --Tim > > > > > > > > > > > > --- adam koeppel wrote: > > > > > >> Hi Tim, > > >> > > >> I ordered a POV kit earlier to play around with. I > figured it > > >> would > > >> not supply enough currents for a massive array. Your > > >> transistor > > >> solution should work fine. If you want to play around > with > > >> any of > > >> your ideas prior to the meeting, I will let you know when > I > > >> have > > >> assembled the kit. I would be happy to share it as a > > >> "testing" unit > > >> so we don't have to complicate the group order. > > >> > > >> Cheers, > > >> > > >> Adam > > >> > > >> > > >> On 12/6/07, Tim Slagle wrote: > > >>> Sign me up for a kit, but I would probably want it > before > > >> the > > >>> meeting so I can put it together in advance. If other > > >> people > > >>> want to do this it will complicate the logistics of a > volume > > >>> order I'm afraid. > > >>> > > >>> Also, the circuit that drives the cube is a hack, and > > >> probably > > >>> wouldn't work too well to drive multiple cubes without > > >>> additional parts. The cube is driven as three > multiplexed > > >>> planes of 3x3=9 LEDs. The LEDs in a plane are driven > > >> directly > > >>> from the AVR uC pins, which is okay, since they can > drive > > >> about > > >>> 25mA. But then the planes are addressed by pulling the > > >> current > > >>> from the whole 9 LEDs into a single AVR uC pin, which is > a > > >> lot > > >>> more current than the AVR can sink. So, the cubes will > > >> already > > >>> be operating at ~1/27th the brightness of a directly > driven > > >> LED, > > >>> and adding more cubes in parallel would only make them > > >> dimmer. > > >>> One change that could be easily done to increase > brightness > > >> is > > >>> use two AVR pins in parallel to sink current from the > > >> planes. I > > >>> think there are enough extra I/O pins to do this for the > > >> 3x3x3 > > >>> cube. The firmware would then have to be changed to set > two > > >>> bits instead of one to address the planes, but this > should > > >> not > > >>> be a big deal. > > >>> > > >>> A better approach would be to drive the planes through a > > >>> transistor that could sink more current. This would > require > > >>> soldering three ~1Kohm resistors and 2N3904 or 2N2222 > NPN > > >>> transistors to the plane drive I/O pins, and inverting > the > > >> bit > > >>> values of the pins in the firmware. > > >>> > > >>> I would recommend making the LED cubes on a piece of > perf > > >> board > > >>> if possible, so there would be room to wire up the drive > > >>> transistors on the board and you wouldn't have to solder > > >> them > > >>> directly to the POV kit. But then, I think like an > engineer > > >> :-) > > >>> Mark, if you make the LED grid assembly fixtures, space > the > > >> LEDs > > >>> at some multiple of 0.1" so they will fit on a > perfboard. > > >> They > > >>> need to be less than 1" apart so I'd say make them 0.7" > or > > >> so. > > >>> One variation I've been thinking about that would be > cool > > >> (but > > >>> require more firmware changes) would be to use bi-color > > >> LEDs. > > >>> As long as the drive voltage is kept around 3V and > two-pin > > >>> reverse-connected LEDs are used, they could just be > wired up > > >>> like the single-color cube. Then in the software, the > I/O > > >> pins > > >>> for inactive planes are set to be high-impedance inputs > so > > >> no > > >>> current will flow, and the active plane is set high to > > >> address > > >>> one color and low to address the other color. So the > matrix > > >>> would be scanned like six planes of 3x3 with only one > color > > >> on > > >>> at a time. The plane bit values for the high-level > > >> addressed > > >>> color would have to be inverted since they are now > active > > >> low. > > >>> I will try to buy some bipolar bi-color LEDs for my own > use > > >> but > > >>> others may want them as well... > > >>> --Tim > > >>> > > >>> > > >>> > > >>> > > >>> > > >>> --- adam koeppel wrote: > > >>> > > >>>> Yeah, if this works out well, it could be an > installation > > >>>> worthy > > >>>> piece. I definitely think the working towards a > massive > > >>>> assembly > > >>>> approach is a good idea, and it will solve the shortage > of > > >> POV > > >>>> kit > > >>>> problem. We should probably do a little design work > ahead > > >> of > > >>>> time to > > >>>> make sure a single POV kit can provide the power we > need, > > >>>> although I > > >>>> don't imagine it will be a problem. I'd just hate for > it > > >> not > > >>>> to work > > >>>> because of a power shortage. What do you guys think? > > >>>> > > >>>> > > >>>> > > >>>> On 12/6/07, Alberto Gait?n > > >> wrote: > > >>>>> Yes! I like the idea of divving up the work > > >> factory-style! > > >>>> ...some folks > > >>>>> building cubes, and others POV thingies. And the idea > > >> for a > > >>>>> mega-LED-cube is genius enough to stop traffic for > hours > > >> in > > >>>> Boston! > > >>>>> A > > >>>>> > > >>>>> > > >>>>> > > >>>>> On 12/6/07 11:33 AM, R. Mark Adams, Ph.D. wrote: > > >>>>>> I think this sounds great- if we follow the 'sewing > > >>>> circle' approach, > > >>>>>> people are certain to feel like they had an enjoyable > > >>>> time, as well as > > >>>>>> (potentially) making something interesting. I would > > >>>> suggest that we buy > > >>>>>> and build at least a couple of POV kits in advance, > so > > >>>> people who finish > > >>>>>> their cubes could hook them up and get so see what > > >> they > > >>>> look like working. > > >>>>>> in fact, if we encourage the group to work together > > >>>> collectively, we > > >>>>>> could set it up so that folks are each working on > > >> parts > > >>>> that can all come > > >>>>>> together in the end to have something working. > > >>>> mega-LED-cube, anyone? :-) > > >>>>>> I am happy to volunteer to buy a couple of kits/LEDs > > >> to do > > >>>> some > > >>>>>> pre-building if people would like. I can also knock > > >> off > > >>>> some wooden jigs > > >>>>>> to aid in the LED cube construction. (I can use the > > >> robot > > >>>> I showed last > > >>>>>> time to make them- cool!) > > >>>>>> > > >>>>>> I also have some tool kits and soldering irons that > > >>>> tool-less folks can > > >>>>>> use at the meeting if they want. > > >>>>>> > > >>>>>> Thanks! > > >>>>>> Mark > > >>>>>> > > >>>>>> Gareth Branwyn wrote: > > >>>>>>> Hey Everybody, > > >>>>>>> > > >>>>>>> As I'm sure you all know, we need to step on it to > > >> get > > >>>> the LED Cube > > >>>>>>> workshop in gear. > > >>>>>>> > > >>>>>>> I talked to Dan Woods at the Maker Store and it's > not > > >>>> firm yet, but > > >>>>>>> it sounds like they'lll sell us the MiniPOV kits for > > >> cost > > >>>> in exchange > > >>>>>>> for a "Sponsored by MAKE" and a link on their > > >> website, in > > >>>> the > > >>>>>>> announcements, etc. The problem is that, given the > > >>>> season, the kits > > >>>>>>> are in short supply. He said supply should free up > > >> after > > >>>> Xmas, so > > >>>>>>> hopefully they could have them to us in early > > >> January. > > >>>>>>> Tim Slagle said that he could get the LEDs > > >> themselves. > > >>>> Katie Bechtold > > >>>>>>> and Mark Adams have also volunteered to help. (all > > >> copied > > >>>> in here) > > >>>>>>> Alberto said that he'll draft the announcement that > > >>>> Koshland needs to > > >>>>>>> see, sooner than later. I'll also help in editing > > >> that. > > >>>>>>> So, we need to figure out ASAP how we're going to > run > > >>>> this thing. > > >>>>>>> Personally, I'm not that concerned about whether the > > >>>> cubes are > > >>>>>>> finished by the end of the workshop or not. To me, > > >> these > > >>>> things are > > >>>>>>> more like a sewing circle than anything else, a > > >> chance to > > >>>> socialize, > > >>>>>>> geek out, learn a skill and a few tips from those > > >> more > > >>>> experienced, > > >>>>>>> etc. But others might have a different take. > > >>>>>>> > > >>>>>>> Given the "shortage" of POV kits, we may have > trouble > > >>>> getting a lot, > > >>>>>>> if say, 25 or more people each wanted a kit. One > > >> thing we > > >>>> could do is > > >>>>>>> also approach Lady Ada, the maker, and see if she'd > > >> give > > >>>> us a > > >>>>>>> discount. Even if she didn't, we could buy them full > > >>>> price from her > > >>>>>>> (at $17.50 ea) and spread out the cost over all the > > >> kits > > >>>> we offered > > >>>>>>> to people. > > >>>>>>> > > >>>>>>> So, we need to get a show of hands ASAP for how many > > >>>> people plan to > > >>>>>>> purchase a kit. And for one thing, we should insist > > >> that > > >>>> you have to > > >>>>>>> be participating in the workshop to get the kit at > > >> the > > >>>> discounted price. > > >>>>>>> Gareth > > >>>>>>> > > >>>>>>> > > >>>>>> > > >>> > > > > > > > > > From cryptovariable at gmail.com Thu Dec 6 20:19:16 2007 From: cryptovariable at gmail.com (Jacob Smith) Date: Thu Dec 6 20:19:24 2007 Subject: [dorkbotdc-blabber] Dorkbot DC + Make DC workshop: show of hands In-Reply-To: <475793CE.8050600@dorkbot.org> References: <475793CE.8050600@dorkbot.org> Message-ID: <1196990356.14582.4.camel@jacob-laptop> Hi! If this is something you think my somewhat-clumsy 13 year old daughter can do, put me down for 2 kits. jake On Thu, 2007-12-06 at 01:16 -0500, Dorkbot DC wrote: > Howdy dorks, > > We need a show of hands to see how many of you are interested in > attending the 16 January 2008, 7-9pm, joint Dorkbot DC + Make: DC > (always FREE, except for materials) workshop meeting at the Marian > Koshland Science Museum of the National Academy of Sciences (@ 5th & E > Sts, NW DC). We'll be building the LED cube: > > http://tinyurl.com/yoddhh > > We're trying to get volume discounts on materialss for the workshop and > it would help to see how much *serious* interest there is out there. > > What say you? > > Thanks, > > Alberto > > > > ........................................................................ > .......dorkbot dc: people doing strange things with electricity......... > ................... http://dorkbot.org/dorkbotdc ....................... > ........................................................................ From alberto.gaitan at gmail.com Thu Dec 6 21:11:37 2007 From: alberto.gaitan at gmail.com (=?ISO-8859-1?Q?Alberto_Gait=E1n?=) Date: Thu Dec 6 21:11:48 2007 Subject: [dorkbotdc-blabber] Dorkbot DC + Make DC workshop: show of hands In-Reply-To: <1196990356.14582.4.camel@jacob-laptop> References: <475793CE.8050600@dorkbot.org> <1196990356.14582.4.camel@jacob-laptop> Message-ID: <4758ABD9.5090703@gmail.com> Sorry, Jake, but we can't make that decision. It's your call. Let me know. Thanks, Alberto On 12/6/07 8:19 PM, Jacob Smith wrote: > Hi! > If this is something you think my somewhat-clumsy 13 year old daughter > can do, put me down for 2 kits. > > jake > > On Thu, 2007-12-06 at 01:16 -0500, Dorkbot DC wrote: >> Howdy dorks, >> >> We need a show of hands to see how many of you are interested in >> attending the 16 January 2008, 7-9pm, joint Dorkbot DC + Make: DC >> (always FREE, except for materials) workshop meeting at the Marian >> Koshland Science Museum of the National Academy of Sciences (@ 5th & E >> Sts, NW DC). We'll be building the LED cube: >> >> http://tinyurl.com/yoddhh >> >> We're trying to get volume discounts on materialss for the workshop and >> it would help to see how much *serious* interest there is out there. >> >> What say you? >> >> Thanks, >> >> Alberto >> >> >> >> ........................................................................ >> .......dorkbot dc: people doing strange things with electricity......... >> ................... http://dorkbot.org/dorkbotdc ....................... >> ........................................................................ > > ........................................................................ > .......dorkbot dc: people doing strange things with electricity......... > ................... http://dorkbot.org/dorkbotdc ....................... > ........................................................................ > From rmadams at epotential.com Thu Dec 6 23:06:18 2007 From: rmadams at epotential.com (R. Mark Adams, Ph.D.) Date: Thu Dec 6 23:07:10 2007 Subject: [dorkbotdc-blabber] Dorkbot DC + Make DC workshop: show of hands In-Reply-To: <4758ABD9.5090703@gmail.com> References: <475793CE.8050600@dorkbot.org> <1196990356.14582.4.camel@jacob-laptop> <4758ABD9.5090703@gmail.com> Message-ID: <1775.69.138.174.76.1197000378.squirrel@mail4.webfaction.com> As a data point, my daughters (age 7 and 10) really enjoyed working on the solar-roller Dorkbot project. We made one for all of us, and although they did a lot of the construction, I helped them with the soldering, since it was pretty tiny. The funny part was that my 7-year-old did somewhat better at it than my 10-year-old. Everyone had a great time, though. Bottom line- my suggestion is to get one and work on it together- that way nobody gets frustrated... :-) -Mark Alberto Gait?n wrote: > Sorry, Jake, but we can't make that decision. It's your call. Let me know. > > Thanks, > > Alberto > > > > On 12/6/07 8:19 PM, Jacob Smith wrote: >> Hi! >> If this is something you think my somewhat-clumsy 13 year old daughter >> can do, put me down for 2 kits. >> >> jake >> >> On Thu, 2007-12-06 at 01:16 -0500, Dorkbot DC wrote: >>> Howdy dorks, >>> >>> We need a show of hands to see how many of you are interested in >>> attending the 16 January 2008, 7-9pm, joint Dorkbot DC + Make: DC >>> (always FREE, except for materials) workshop meeting at the Marian >>> Koshland Science Museum of the National Academy of Sciences (@ 5th & E >>> Sts, NW DC). We'll be building the LED cube: >>> >>> http://tinyurl.com/yoddhh >>> >>> We're trying to get volume discounts on materialss for the workshop and >>> it would help to see how much *serious* interest there is out there. >>> >>> What say you? >>> >>> Thanks, >>> >>> Alberto >>> >>> >>> >>> ........................................................................ >>> .......dorkbot dc: people doing strange things with >>> electricity......... >>> ................... http://dorkbot.org/dorkbotdc >>> ....................... >>> ........................................................................ >> >> ........................................................................ >> .......dorkbot dc: people doing strange things with electricity......... >> ................... http://dorkbot.org/dorkbotdc ....................... >> ........................................................................ >> > ........................................................................ > .......dorkbot dc: people doing strange things with electricity......... > ................... http://dorkbot.org/dorkbotdc ....................... > ........................................................................ > > -- | | "Information is light. | | R. Mark Adams, Ph.D. | Information in itself, | | Computational Biologist | about anything, is light." | | rmadams@epotential.com | - Tom Stoppard | From roywright at comcast.net Thu Dec 6 23:19:15 2007 From: roywright at comcast.net (Roy Wright) Date: Thu Dec 6 23:16:29 2007 Subject: FW: [dorkbotdc-blabber] re: Dorkbot DC + Make DC workshop: show of hands (M@) Message-ID: <000b01c83888$56e8bc60$04ba3520$@net> Put me down for two kits; one of which is for my 9 year grandson. Roy Wright Alexandria, VA -----Original Message----- From: dorkbotdc-blabber-bounces@music.columbia.edu [mailto:dorkbotdc-blabber-bounces@music.columbia.edu] On Behalf Of Jesse Aronson Sent: Thursday, December 06, 2007 5:02 PM To: dorkbotdc-blabber@music.columbia.edu Subject: [dorkbotdc-blabber] re: Dorkbot DC + Make DC workshop: show of hands (M@) I've been a lurker on the list for a while. For the new year I think I'll jump in & come on down. Put me down for a kit. Jesse > 5. Re: Dorkbot DC + Make DC workshop: show of hands (M@) > ........................................................................ .......dorkbot dc: people doing strange things with electricity......... ................... http://dorkbot.org/dorkbotdc ....................... ........................................................................ From me at psmay.com Thu Dec 6 23:37:52 2007 From: me at psmay.com (Peter S. May) Date: Thu Dec 6 23:37:57 2007 Subject: [dorkbotdc-blabber] Dorkbot DC + Make DC workshop: show of hands In-Reply-To: <475793CE.8050600@dorkbot.org> References: <475793CE.8050600@dorkbot.org> Message-ID: <4758CE20.7010701@psmay.com> Dorkbot DC wrote: > We need a show of hands to see how many of you are interested in > attending the 16 January 2008, 7-9pm, joint Dorkbot DC + Make: DC > (always FREE, except for materials) workshop meeting at the Marian > Koshland Science Museum of the National Academy of Sciences (@ 5th & E > Sts, NW DC). We'll be building the LED cube: Despite the fact that I have my own LEDs, my own pile of cheap SSOP PIC16F54s, and a PICkit 2, and have even recently made my own POV toy with said items, and am on top of that expecting a Boarduino for Ecksmas, put me down for one iff you're one short of the discount. :-) I can also have a couple of irons on hand, though both are of the ghetto variety (one is a RadioShack 15W and the other a $5 30W firestarter from Harbor Freight). If anyone's considering taking the Arduino route suggested by Mr. Slagle, I'll also volunteer my PowerBook's USB port (probably with an external hub as insurance from any soldering errors...). Word PSM From dbrunton at yahoo.com Fri Dec 7 12:12:16 2007 From: dbrunton at yahoo.com (David Brunton) Date: Fri Dec 7 12:12:25 2007 Subject: [dorkbotdc-blabber] re: Dorkbot DC + Make DC workshop: show of hands (M@) Message-ID: <639002.69522.qm@web52301.mail.re2.yahoo.com> I'll take one. ----- Original Message ---- From: Jesse Aronson To: dorkbotdc-blabber@music.columbia.edu Sent: Thursday, December 6, 2007 5:01:37 PM Subject: [dorkbotdc-blabber] re: Dorkbot DC + Make DC workshop: show of hands (M@) I've been a lurker on the list for a while. For the new year I think I'll jump in & come on down. Put me down for a kit. Jesse > 5. Re: Dorkbot DC + Make DC workshop: show of hands (M@) > ........................................................................ .......dorkbot dc: people doing strange things with electricity......... ................... http://dorkbot.org/dorkbotdc ....................... ........................................................................ ____________________________________________________________________________________ Looking for last minute shopping deals? Find them fast with Yahoo! Search. http://tools.search.yahoo.com/newsearch/category.php?category=shopping From rmadams at epotential.com Sat Dec 8 20:22:53 2007 From: rmadams at epotential.com (R. Mark Adams, Ph.D.) Date: Sat Dec 8 20:23:15 2007 Subject: [dorkbotdc-blabber] Re: LED Cube Workshop - use an Arduino? In-Reply-To: <762301.75297.qm@web30601.mail.mud.yahoo.com> References: <762301.75297.qm@web30601.mail.mud.yahoo.com> Message-ID: <475B436D.9030807@epotential.com> -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Okay- I think I have a way to get the Arduino to run the LEDs without needing anything fancy (read shift registers, etc.) Now I need a way to test it, and I do not have enough LEDs. Someone (Tim?) had mentioned that they buy LEDs on ebay and have good luck doing so- any suggestions as to a vendor, delivery time and price? I figured it might be the best way to get some quickly to we can test out our ideas! :-) Thanks- Mark Tim Slagle wrote: > I know you would want to use Make: stuff when possible but there > are hundreds of Arduinos in stock at AdaFruit: > http://www.adafruit.com/index.php?main_page=index&cPath=17 > SparcFun also has them: > http://www.sparkfun.com/commerce/product_info.php?products_id=666 > > I think the AdaFruit BoArduino would be the thing to use > however, then the transistor drive circuits and LED column > connections can just be plugged in to the protoboard without > soldering: > http://www.adafruit.com/index.php?main_page=product_info&cPath=19&products_id=72 > Lots of those in stock also, but they are sold as kits and would > need to be soldered up. No harder than building a MiniPOV kit > and more useful in the future... > --Tim > > > --- adam koeppel wrote: > > >>I probably have time, but maybe not the skill. Also, MAKE >>store is >>currently out of Arduinos... Damn holiday season... I love >>the idea >>of everyone having an Arduino for this and future projects. >> >>On 12/6/07, Alberto Gait?n wrote: >> >>>This is a great idea. Especially because everk >> >>self-respecting maker >> >>>needs an Arduino. I'm pretty sure I don't have the time for >> >>this >> >>>conversion. If none of you do, either, perhaps we can >> >>recruit someone >> >>>else from the greater list? >>> >>>The Arduino uses Processing as its language and it's pretty >> >>well >> >>>documented. Haven't looked at the WinAVR C code and don't >> >>know how many >> >>>lines o'code it has but someone with some chops could make >> >>short shrift >> >>>of it. Can't be too long. >>> >>>Anyone else have the time to do this? >>> >>>Alberto >>> >>> >>> >>>On 12/6/07 4:07 PM, Tim Slagle wrote: >>> >>>>Thanks for the offer, but now that I think of it I have >> >>some AVR >> >>>>prototyping boards that could be used instead of the >> >>MiniPOV kit >> >>>>for my experimental purposes. >>>> >>>>This may complicate things even more, but instead of using >>>>hacking the MiniPOV kit the LED cube could be driven from >> >>an >> >>>>Arduino. Someone would just have to convert the software >> >>from >> >>>>WinAVR C to Arduino's Java-style code. Then commercial >> >>Arduinos >> >>>>could be bought, or kits could be made. If people >> >>bought >> >>>>assembled Arduinos they could focus on making the LED cube >> >>at >> >>>>the meeting. And their Arduino could be the basis of >> >>future >> >>>>Make:DC projects as well. >>>> >>>>I would tentatively volunteer to do the software >> >>conversion but >> >>>>if there is someone else with more confirmed free time it >> >>might >> >>>>be better. The Make: 3D cube C code could also just be >> >>burned >> >>>>into the Arduino CPU (blowing away the bootloader etc) as >> >>a >> >>>>backup plan. >>>>--Tim >>>> >>>> >>>> >>>>--- adam koeppel wrote: >>>> >>>> >>>>>Hi Tim, >>>>> >>>>>I ordered a POV kit earlier to play around with. I >> >>figured it >> >>>>>would >>>>>not supply enough currents for a massive array. Your >>>>>transistor >>>>>solution should work fine. If you want to play around >> >>with >> >>>>>any of >>>>>your ideas prior to the meeting, I will let you know when >> >>I >> >>>>>have >>>>>assembled the kit. I would be happy to share it as a >>>>>"testing" unit >>>>>so we don't have to complicate the group order. >>>>> >>>>>Cheers, >>>>> >>>>>Adam >>>>> >>>>> >>>>>On 12/6/07, Tim Slagle wrote: >>>>> >>>>>>Sign me up for a kit, but I would probably want it >> >>before >> >>>>>the >>>>> >>>>>>meeting so I can put it together in advance. If other >>>>> >>>>>people >>>>> >>>>>>want to do this it will complicate the logistics of a >> >>volume >> >>>>>>order I'm afraid. >>>>>> >>>>>>Also, the circuit that drives the cube is a hack, and >>>>> >>>>>probably >>>>> >>>>>>wouldn't work too well to drive multiple cubes without >>>>>>additional parts. The cube is driven as three >> >>multiplexed >> >>>>>>planes of 3x3=9 LEDs. The LEDs in a plane are driven >>>>> >>>>>directly >>>>> >>>>>>from the AVR uC pins, which is okay, since they can >> >>drive >> >>>>>about >>>>> >>>>>>25mA. But then the planes are addressed by pulling the >>>>> >>>>>current >>>>> >>>>>>from the whole 9 LEDs into a single AVR uC pin, which is >> >>a >> >>>>>lot >>>>> >>>>>>more current than the AVR can sink. So, the cubes will >>>>> >>>>>already >>>>> >>>>>>be operating at ~1/27th the brightness of a directly >> >>driven >> >>>>>LED, >>>>> >>>>>>and adding more cubes in parallel would only make them >>>>> >>>>>dimmer. >>>>> >>>>>>One change that could be easily done to increase >> >>brightness >> >>>>>is >>>>> >>>>>>use two AVR pins in parallel to sink current from the >>>>> >>>>>planes. I >>>>> >>>>>>think there are enough extra I/O pins to do this for the >>>>> >>>>>3x3x3 >>>>> >>>>>>cube. The firmware would then have to be changed to set >> >>two >> >>>>>>bits instead of one to address the planes, but this >> >>should >> >>>>>not >>>>> >>>>>>be a big deal. >>>>>> >>>>>>A better approach would be to drive the planes through a >>>>>>transistor that could sink more current. This would >> >>require >> >>>>>>soldering three ~1Kohm resistors and 2N3904 or 2N2222 >> >>NPN >> >>>>>>transistors to the plane drive I/O pins, and inverting >> >>the >> >>>>>bit >>>>> >>>>>>values of the pins in the firmware. >>>>>> >>>>>>I would recommend making the LED cubes on a piece of >> >>perf >> >>>>>board >>>>> >>>>>>if possible, so there would be room to wire up the drive >>>>>>transistors on the board and you wouldn't have to solder >>>>> >>>>>them >>>>> >>>>>>directly to the POV kit. But then, I think like an >> >>engineer >> >>>>>:-) >>>>> >>>>>>Mark, if you make the LED grid assembly fixtures, space >> >>the >> >>>>>LEDs >>>>> >>>>>>at some multiple of 0.1" so they will fit on a >> >>perfboard. >> >>>>>They >>>>> >>>>>>need to be less than 1" apart so I'd say make them 0.7" >> >>or >> >>>>>so. >>>>> >>>>>>One variation I've been thinking about that would be >> >>cool >> >>>>>(but >>>>> >>>>>>require more firmware changes) would be to use bi-color >>>>> >>>>>LEDs. >>>>> >>>>>>As long as the drive voltage is kept around 3V and >> >>two-pin >> >>>>>>reverse-connected LEDs are used, they could just be >> >>wired up >> >>>>>>like the single-color cube. Then in the software, the >> >>I/O >> >>>>>pins >>>>> >>>>>>for inactive planes are set to be high-impedance inputs >> >>so >> >>>>>no >>>>> >>>>>>current will flow, and the active plane is set high to >>>>> >>>>>address >>>>> >>>>>>one color and low to address the other color. So the >> >>matrix >> >>>>>>would be scanned like six planes of 3x3 with only one >> >>color >> >>>>>on >>>>> >>>>>>at a time. The plane bit values for the high-level >>>>> >>>>>addressed >>>>> >>>>>>color would have to be inverted since they are now >> >>active >> >>>>>low. >>>>> >>>>>>I will try to buy some bipolar bi-color LEDs for my own >> >>use >> >>>>>but >>>>> >>>>>>others may want them as well... >>>>>>--Tim >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> >>>>>>--- adam koeppel wrote: >>>>>> >>>>>> >>>>>>>Yeah, if this works out well, it could be an >> >>installation >> >>>>>>>worthy >>>>>>>piece. I definitely think the working towards a >> >>massive >> >>>>>>>assembly >>>>>>>approach is a good idea, and it will solve the shortage >> >>of >> >>>>>POV >>>>> >>>>>>>kit >>>>>>>problem. We should probably do a little design work >> >>ahead >> >>>>>of >>>>> >>>>>>>time to >>>>>>>make sure a single POV kit can provide the power we >> >>need, >> >>>>>>>although I >>>>>>>don't imagine it will be a problem. I'd just hate for >> >>it >> >>>>>not >>>>> >>>>>>>to work >>>>>>>because of a power shortage. What do you guys think? >>>>>>> >>>>>>> >>>>>>> >>>>>>>On 12/6/07, Alberto Gait?n >>>>> >>>>>wrote: >>>>> >>>>>>>>Yes! I like the idea of divving up the work >>>>> >>>>>factory-style! >>>>> >>>>>>>...some folks >>>>>>> >>>>>>>>building cubes, and others POV thingies. And the idea >>>>> >>>>>for a >>>>> >>>>>>>>mega-LED-cube is genius enough to stop traffic for >> >>hours >> >>>>>in >>>>> >>>>>>>Boston! >>>>>>> >>>>>>>>A >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>>On 12/6/07 11:33 AM, R. Mark Adams, Ph.D. wrote: >>>>>>>> >>>>>>>>>I think this sounds great- if we follow the 'sewing >>>>>>> >>>>>>>circle' approach, >>>>>>> >>>>>>>>>people are certain to feel like they had an enjoyable >>>>>>> >>>>>>>time, as well as >>>>>>> >>>>>>>>>(potentially) making something interesting. I would >>>>>>> >>>>>>>suggest that we buy >>>>>>> >>>>>>>>>and build at least a couple of POV kits in advance, >> >>so >> >>>>>>>people who finish >>>>>>> >>>>>>>>>their cubes could hook them up and get so see what >>>>> >>>>>they >>>>> >>>>>>>look like working. >>>>>>> >>>>>>>>> in fact, if we encourage the group to work together >>>>>>> >>>>>>>collectively, we >>>>>>> >>>>>>>>>could set it up so that folks are each working on >>>>> >>>>>parts >>>>> >>>>>>>that can all come >>>>>>> >>>>>>>>>together in the end to have something working. >>>>>>> >>>>>>>mega-LED-cube, anyone? :-) >>>>>>> >>>>>>>>>I am happy to volunteer to buy a couple of kits/LEDs >>>>> >>>>>to do >>>>> >>>>>>>some >>>>>>> >>>>>>>>>pre-building if people would like. I can also knock >>>>> >>>>>off >>>>> >>>>>>>some wooden jigs >>>>>>> >>>>>>>>>to aid in the LED cube construction. (I can use the >>>>> >>>>>robot >>>>> >>>>>>>I showed last >>>>>>> >>>>>>>>>time to make them- cool!) >>>>>>>>> >>>>>>>>>I also have some tool kits and soldering irons that >>>>>>> >>>>>>>tool-less folks can >>>>>>> >>>>>>>>>use at the meeting if they want. >>>>>>>>> >>>>>>>>>Thanks! >>>>>>>>>Mark >>>>>>>>> >>>>>>>>>Gareth Branwyn wrote: >>>>>>>>> >>>>>>>>>>Hey Everybody, >>>>>>>>>> >>>>>>>>>>As I'm sure you all know, we need to step on it to >>>>> >>>>>get >>>>> >>>>>>>the LED Cube >>>>>>> >>>>>>>>>>workshop in gear. >>>>>>>>>> >>>>>>>>>>I talked to Dan Woods at the Maker Store and it's >> >>not >> >>>>>>>firm yet, but >>>>>>> >>>>>>>>>>it sounds like they'lll sell us the MiniPOV kits for >>>>> >>>>>cost >>>>> >>>>>>>in exchange >>>>>>> >>>>>>>>>>for a "Sponsored by MAKE" and a link on their >>>>> >>>>>website, in >>>>> >>>>>>>the >>>>>>> >>>>>>>>>>announcements, etc. The problem is that, given the >>>>>>> >>>>>>>season, the kits >>>>>>> >>>>>>>>>>are in short supply. He said supply should free up >>>>> >>>>>after >>>>> >>>>>>>Xmas, so >>>>>>> >>>>>>>>>>hopefully they could have them to us in early >>>>> >>>>>January. >>>>> >>>>>>>>>>Tim Slagle said that he could get the LEDs >>>>> >>>>>themselves. >>>>> >>>>>>>Katie Bechtold >>>>>>> >>>>>>>>>>and Mark Adams have also volunteered to help. (all >>>>> >>>>>copied >>>>> >>>>>>>in here) >>>>>>> >>>>>>>>>>Alberto said that he'll draft the announcement that >>>>>>> >>>>>>>Koshland needs to >>>>>>> >>>>>>>>>>see, sooner than later. I'll also help in editing >>>>> >>>>>that. >>>>> >>>>>>>>>>So, we need to figure out ASAP how we're going to >> >>run >> >>>>>>>this thing. >>>>>>> >>>>>>>>>>Personally, I'm not that concerned about whether the >>>>>>> >>>>>>>cubes are >>>>>>> >>>>>>>>>>finished by the end of the workshop or not. To me, >>>>> >>>>>these >>>>> >>>>>>>things are >>>>>>> >>>>>>>>>>more like a sewing circle than anything else, a >>>>> >>>>>chance to >>>>> >>>>>>>socialize, >>>>>>> >>>>>>>>>>geek out, learn a skill and a few tips from those >>>>> >>>>>more >>>>> >>>>>>>experienced, >>>>>>> >>>>>>>>>>etc. But others might have a different take. >>>>>>>>>> >>>>>>>>>>Given the "shortage" of POV kits, we may have >> >>trouble >> >>>>>>>getting a lot, >>>>>>> >>>>>>>>>>if say, 25 or more people each wanted a kit. One >>>>> >>>>>thing we >>>>> >>>>>>>could do is >>>>>>> >>>>>>>>>>also approach Lady Ada, the maker, and see if she'd >>>>> >>>>>give >>>>> >>>>>>>us a >>>>>>> >>>>>>>>>>discount. Even if she didn't, we could buy them full >>>>>>> >>>>>>>price from her >>>>>>> >>>>>>>>>>(at $17.50 ea) and spread out the cost over all the >>>>> >>>>>kits >>>>> >>>>>>>we offered >>>>>>> >>>>>>>>>>to people. >>>>>>>>>> >>>>>>>>>>So, we need to get a show of hands ASAP for how many >>>>>>> >>>>>>>people plan to >>>>>>> >>>>>>>>>>purchase a kit. And for one thing, we should insist >>>>> >>>>>that >>>>> >>>>>>>you have to >>>>>>> >>>>>>>>>>be participating in the workshop to get the kit at >>>>> >>>>>the >>>>> >>>>>>>discounted price. >>>>>>> >>>>>>>>>>Gareth >>>>>>>>>> >>>>>>>>>> >>>>>>>>> >>>> > > - -- | | "Information is light. | | R. Mark Adams, Ph.D. | Information in itself, | | Computational Biologist | about anything, is light." | | rmadams@epotential.com | - Tom Stoppard | -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.1 (Darwin) Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org iD8DBQFHW0Ns5rQGeNhqYzcRAkG2AJ9n/eokxhA3+S6KoMrdYT1wI56NMwCfc5+X 0O9MFxbmDtbSc3mEFHus1kQ= =XK3+ -----END PGP SIGNATURE----- From me at psmay.com Sat Dec 8 23:00:26 2007 From: me at psmay.com (Peter S. May) Date: Sat Dec 8 23:05:16 2007 Subject: [dorkbotdc-blabber] Re: LED Cube Workshop - use an Arduino? In-Reply-To: <475B436D.9030807@epotential.com> References: <762301.75297.qm@web30601.mail.mud.yahoo.com> <475B436D.9030807@epotential.com> Message-ID: <475B685A.3070801@psmay.com> R. Mark Adams, Ph.D. wrote: > Okay- I think I have a way to get the Arduino to run the LEDs without > needing anything fancy (read shift registers, etc.) Now I need a way to > test it, and I do not have enough LEDs. Someone (Tim?) had mentioned > that they buy LEDs on ebay and have good luck doing so- any suggestions > as to a vendor, delivery time and price? I figured it might be the best > way to get some quickly to we can test out our ideas! :-) > > Thanks- > Mark I've so far had decent luck buying LEDs and certain other electronics items (CR2032 coin cells, for example) from the various China/Hong Kong (gray market?) sellers. It just happens that both LED orders I've placed came from giorgio11185, aka "Asia Engineer". No complaints so far, other than the 17-20 days it takes to ship since it's not domestic, and at least in my experience 12 cents shipped (lot of 100) is a good price for a high-brightness white LED. Some come with free resistors; see the auction description if you want to ask for resistors adjusted for 5V (the default is often 12V). Your mileage may vary, but for me it's been unproblematic and worth the wait. (As with any LED, take note of both spot brightness (mcd) and viewing angle (degrees) when picking one out.) Incidentally, what is this way you have to drive the LEDs "without needing anything fancy"? Is it different than the multiplexing method used by Bre and Mitch? Getting pedantic for the benefit of the unaware, so please skip with my apologies if this doesn't include you. :-) Somebody who's done the Make version of this project, please tell me if the following description is correct--I took a look at the PDF for the Make mod of MiniPOV for the 3x3x3 cube, and it wasn't trivial to decode. But from what I can tell they took the 8 LED outputs already on the kit, added one more by sticking a resistor onto one of the other I/O pins, and then implemented the multiplexing by using three more of the I/Os as a ground select. The result looks a bit like the following ASCIImatic: . (X,Y,TOP) . XY ---/\/\--+->|-------------------- /TOP . | (X,Y,MID) . +----->|---------------- /MID . | (X,Y,BOT) . +--------->|------------ /BOT Where XY is _each_ of . NW N0 NE . 0W 00 0E . SW S0 SE It's wired up such that all LEDs of a given Z share a cathode and all LEDs of a given XY share an anode. That adds up to 12 I/O pins (9 to select XY and 3 to select the Z layer) and 27 LEDs (one per X per Y per Z). A given LED on the cube will be lit if and only if its anode (XY pin) is high and its cathode (Z pin) is low. The firmware draws the pattern one Z layer at a time by, for example, setting all Z pins high to clear, setting the XY pins to the desired pattern, and then setting the desired Z pin low. By cycling through the layers faster than the viewer's flicker threshold, it appears that all layers are being drawn at the same time. So, assuming the above is true, as long as the Arduino has 12 available outputs it can pull the same trick. More garbage on this topic in the PS. Was this what you had in mind? If not, what? Word PSM Post Scriptum: This is me getting (even more) carried away... There's even a means of addressing 3x3x3 = 27 LEDs (or as many as 30) using only 6 pins, as long as each one is tri-state-able. But this method can typically only address one LED at a time (as opposed to one layer) and it majorly complicates the firmware. (See also "Charlieplexing".) An unrelated project I have going on is a little heavy duty for any sort of multiplexing and instead uses a small fleet of 74HC595 shift registers. For an immense number of LEDs (over 60 in my case) it's a bit more straightforward and can use as few as 3 pins for an arbitrarily large number of LEDs--as long as you buy one 74HC595 for every 8 LEDs. From tim at slagle.org Sat Dec 8 23:11:29 2007 From: tim at slagle.org (Tim Slagle) Date: Sat Dec 8 23:11:36 2007 Subject: [dorkbotdc-blabber] Re: LED Cube Workshop - use an Arduino? In-Reply-To: <475B436D.9030807@epotential.com> Message-ID: <134140.59100.qm@web30603.mail.mud.yahoo.com> Arduinos have 14 digital I/Os so that should be just enough for the 3x3x3 cube plus the serial port for program load and debugging: http://www.arduino.cc/en/Hacking/PinMapping168 I am no Arduino expert, but I checked out the LED cube C source code from: http://cachefly.oreilly.com/make/LEDcube.zip and then hit the Arduino software reference pages: http://www.arduino.cc/en/Reference/Extended It looks like Arduino supports reading the cube patterns from program memory (rather than variables in RAM) like the C program does. And it lets you write the entire 8-bit port with one statement as well as the standard way of doing each bit individually (which is much slower). So porting the Make code to Arduino should be straightforward enough. Arduino code is C/C++-based rather than Java like I said before - I was thinking of Processing, from which Arduino got the editor environment but not the syntax it seems. --Tim --- "R. Mark Adams, Ph.D." wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > Okay- I think I have a way to get the Arduino to run the LEDs > without > needing anything fancy (read shift registers, etc.) Now I > need a way to > test it, and I do not have enough LEDs. Someone (Tim?) had > mentioned > that they buy LEDs on ebay and have good luck doing so- any > suggestions > as to a vendor, delivery time and price? I figured it might > be the best > way to get some quickly to we can test out our ideas! :-) > > Thanks- > Mark > > Tim Slagle wrote: > > I know you would want to use Make: stuff when possible but > there > > are hundreds of Arduinos in stock at AdaFruit: > > http://www.adafruit.com/index.php?main_page=index&cPath=17 > > SparcFun also has them: > > > http://www.sparkfun.com/commerce/product_info.php?products_id=666 > > > > I think the AdaFruit BoArduino would be the thing to use > > however, then the transistor drive circuits and LED column > > connections can just be plugged in to the protoboard without > > soldering: > > > http://www.adafruit.com/index.php?main_page=product_info&cPath=19&products_id=72 > > Lots of those in stock also, but they are sold as kits and > would > > need to be soldered up. No harder than building a MiniPOV > kit > > and more useful in the future... > > --Tim > > > > > > --- adam koeppel wrote: > > > > > >>I probably have time, but maybe not the skill. Also, MAKE > >>store is > >>currently out of Arduinos... Damn holiday season... I love > >>the idea > >>of everyone having an Arduino for this and future projects. > >> > >>On 12/6/07, Alberto Gait?n wrote: > >> > >>>This is a great idea. Especially because everk > >> > >>self-respecting maker > >> > >>>needs an Arduino. I'm pretty sure I don't have the time for > >> > >>this > >> > >>>conversion. If none of you do, either, perhaps we can > >> > >>recruit someone > >> > >>>else from the greater list? > >>> > >>>The Arduino uses Processing as its language and it's pretty > >> > >>well > >> > >>>documented. Haven't looked at the WinAVR C code and don't > >> > >>know how many > >> > >>>lines o'code it has but someone with some chops could make > >> > >>short shrift > >> > >>>of it. Can't be too long. > >>> > >>>Anyone else have the time to do this? > >>> > >>>Alberto > >>> > >>> > >>> > >>>On 12/6/07 4:07 PM, Tim Slagle wrote: > >>> > >>>>Thanks for the offer, but now that I think of it I have > >> > >>some AVR > >> > >>>>prototyping boards that could be used instead of the > >> > >>MiniPOV kit > >> > >>>>for my experimental purposes. > >>>> > >>>>This may complicate things even more, but instead of using > >>>>hacking the MiniPOV kit the LED cube could be driven from > >> > >>an > >> > >>>>Arduino. Someone would just have to convert the software > >> > >>from > >> > >>>>WinAVR C to Arduino's Java-style code. Then commercial > >> > >>Arduinos > >> > >>>>could be bought, or kits could be made. If people > >> > >>bought > >> > >>>>assembled Arduinos they could focus on making the LED cube > >> > >>at > >> > >>>>the meeting. And their Arduino could be the basis of > >> > >>future > >> > >>>>Make:DC projects as well. > >>>> > >>>>I would tentatively volunteer to do the software > >> > >>conversion but > >> > >>>>if there is someone else with more confirmed free time it > >> > >>might > >> > >>>>be better. The Make: 3D cube C code could also just be > >> > >>burned > >> > >>>>into the Arduino CPU (blowing away the bootloader etc) as > >> > >>a > >> > >>>>backup plan. > >>>>--Tim > >>>> > >>>> > >>>> > >>>>--- adam koeppel wrote: > >>>> > >>>> > >>>>>Hi Tim, > >>>>> > >>>>>I ordered a POV kit earlier to play around with. I > >> > >>figured it > >> > >>>>>would > >>>>>not supply enough currents for a massive array. Your > >>>>>transistor > >>>>>solution should work fine. If you want to play around > >> > >>with > >> > >>>>>any of > >>>>>your ideas prior to the meeting, I will let you know when > >> > >>I > >> > >>>>>have > >>>>>assembled the kit. I would be happy to share it as a > >>>>>"testing" unit > >>>>>so we don't have to complicate the group order. > >>>>> > >>>>>Cheers, > >>>>> > >>>>>Adam > >>>>> > >>>>> > >>>>>On 12/6/07, Tim Slagle wrote: > >>>>> > >>>>>>Sign me up for a kit, but I would probably want it > >> > >>before > >> > >>>>>the > >>>>> > >>>>>>meeting so I can put it together in advance. If other > >>>>> > >>>>>people > >>>>> > >>>>>>want to do this it will complicate the logistics of a > >> > >>volume > >> > >>>>>>order I'm afraid. > >>>>>> > >>>>>>Also, the circuit that drives the cube is a hack, and > >>>>> > >>>>>probably > >>>>> > >>>>>>wouldn't work too well to drive multiple cubes without > >>>>>>additional parts. The cube is driven as three > >> > >>multiplexed > >> > >>>>>>planes of 3x3=9 LEDs. The LEDs in a plane are driven > >>>>> > >>>>>directly > >>>>> > >>>>>>from the AVR uC pins, which is okay, since they can > >> > >>drive > >> > >>>>>about > >>>>> > >>>>>>25mA. But then the planes are addressed by pulling the > >>>>> > >>>>>current > >>>>> > >>>>>>from the whole 9 LEDs into a single AVR uC pin, which is > >> > >>a > >> > >>>>>lot > >>>>> > >>>>>>more current than the AVR can sink. So, the cubes will > >>>>> > >>>>>already > >>>>> > >>>>>>be operating at ~1/27th the brightness of a directly > >> > >>driven > >> > >>>>>LED, > >>>>> > >>>>>>and adding more cubes in parallel would only make them > >>>>> > >>>>>dimmer. > >>>>> > >>>>>>One change that could be easily done to increase > >> > >>brightness > >> > >>>>>is > >>>>> > >>>>>>use two AVR pins in parallel to sink current from the > >>>>> > >>>>>planes. I > >>>>> > >>>>>>think there are enough extra I/O pins to do this for the > >>>>> > >>>>>3x3x3 > >>>>> > >>>>>>cube. The firmware would then have to be changed to set > >> > >>two > >> > >>>>>>bits instead of one to address the planes, but this > >> > >>should > >> > >>>>>not > >>>>> > >>>>>>be a big deal. > >>>>>> > >>>>>>A better approach would be to drive the planes through a > >>>>>>transistor that could sink more current. This would > >> > >>require > >> > >>>>>>soldering three ~1Kohm resistors and 2N3904 or 2N2222 > >> > >>NPN > >> > >>>>>>transistors to the plane drive I/O pins, and inverting > >> > >>the > >> > >>>>>bit > >>>>> > >>>>>>values of the pins in the firmware. > >>>>>> > >>>>>>I would recommend making the LED cubes on a piece of > >> > >>perf > >> > >>>>>board > >>>>> > >>>>>>if possible, so there would be room to wire up the drive > >>>>>>transistors on the board and you wouldn't have to solder > >>>>> > >>>>>them > >>>>> > >>>>>>directly to the POV kit. But then, I think like an > >> > >>engineer > >> > >>>>>:-) > >>>>> > >>>>>>Mark, if you make the LED grid assembly fixtures, space > >> > >>the > >> > >>>>>LEDs > >>>>> > >>>>>>at some multiple of 0.1" so they will fit on a > >> > >>perfboard. > >> > >>>>>They > >>>>> > >>>>>>need to be less than 1" apart so I'd say make them 0.7" > >> > >>or > >> > >>>>>so. > >>>>> > >>>>>>One variation I've been thinking about that would be > >> > >>cool > >> > >>>>>(but > >>>>> > >>>>>>require more firmware changes) would be to use bi-color > >>>>> > >>>>>LEDs. > >>>>> > >>>>>>As long as the drive voltage is kept around 3V and > >> > >>two-pin > >> > >>>>>>reverse-connected LEDs are used, they could just be > >> > >>wired up > >> > >>>>>>like the single-color cube. Then in the software, the > >> > >>I/O > >> > >>>>>pins > >>>>> > >>>>>>for inactive planes are set to be high-impedance inputs > >> > >>so > >> > >>>>>no > >>>>> > >>>>>>current will flow, and the active plane is set high to > >>>>> > >>>>>address > >>>>> > >>>>>>one color and low to address the other color. So the > >> > >>matrix > >> > >>>>>>would be scanned like six planes of 3x3 with only one > >> > >>color > >> > >>>>>on > >>>>> > >>>>>>at a time. The plane bit values for the high-level > >>>>> > >>>>>addressed > >>>>> > >>>>>>color would have to be inverted since they are now > >> > >>active > >> > >>>>>low. > >>>>> > >>>>>>I will try to buy some bipolar bi-color LEDs for my own > >> > >>use > >> > >>>>>but > >>>>> > >>>>>>others may want them as well... > >>>>>>--Tim > >>>>>> > >>>>>> > >>>>>> > >>>>>> > >>>>>> > >>>>>>--- adam koeppel wrote: > >>>>>> > >>>>>> > >>>>>>>Yeah, if this works out well, it could be an > >> > >>installation > >> > >>>>>>>worthy > >>>>>>>piece. I definitely think the working towards a > >> > >>massive > >> > >>>>>>>assembly > >>>>>>>approach is a good idea, and it will solve the shortage > >> > >>of > >> > >>>>>POV > >>>>> > >>>>>>>kit > >>>>>>>problem. We should probably do a little design work > >> > >>ahead > >> > >>>>>of > >>>>> > >>>>>>>time to > >>>>>>>make sure a single POV kit can provide the power we > >> > >>need, > >> > >>>>>>>although I > >>>>>>>don't imagine it will be a problem. I'd just hate for > >> > >>it > >> > >>>>>not > >>>>> > >>>>>>>to work > >>>>>>>because of a power shortage. What do you guys think? > >>>>>>> > >>>>>>> > >>>>>>> > >>>>>>>On 12/6/07, Alberto Gait?n > >>>>> > >>>>>wrote: > >>>>> > >>>>>>>>Yes! I like the