chebe: (Default)
While I wait for LJ to let me log in again (to upload photos), or until I find a better alternative, I thought I'd share some more of the LED-matrix top code with you.

Here's version 2, with the SparkFun wearable keypad functionality added. Let me know if there's any problems, or if you'd simply like to discuss it.

(Version 1 post)
chebe: (You Can Still Be Free)
I received a request for clarify some of the code I use in the LED-matrix top, so I've decided to start sharing my code in a more modern way. But before we get to that, if you are thinking of following my adventures in making this top there are a couple of things I want to add.


  1. Please please please use metal snaps instead of metal rings!

  2. Use lithium-ion batteries, more power, much better.

  3. As soon as you have the circuit working as you want, cover each conductive trace with fray-stop glue to prevent oxidation of the conductive coating over time.

  4. Test that you can turn on each LED individually by using a (at least 3V) coin-cell battery and touching the positive side to the trace that connects to the positive side of the LED, and the negative to the negative. If it doesn't light up get a multimeter and check every single trace/LED for short-circuits.



Okay, so the top is physically made up and working fine? Great! Here's the first version of the code, with the LEDs working, and the push-button switch for cycling through patterns, and that's it. It's available through github at https://github.com/chebe/chebe-led-matrix-top. I'll let you know as I clean up and release newer versions.
chebe: (ThoughtFractal)
Last we looked in on this project I'd just added in the adapter for the keypad and a battery holder. Since then a couple of things happened.

One; in the two-and-a-half years since starting this project, the silver on the conductive thread has started to corrode. This manifested first as the programmed time delays no longer seeming to work right, and then with an un-even light disruption across the LED grid (this happens anyway, but wasn't noticeable before this). So I rather carefully went over every single trace of conductive thread with a thin paintbrush and a bottle of fray-stop glue. Hopefully it will slow down further corrosion.

Two; I got my hands on a IR-detector unit, and wanted to include it in the top (as talked about in the Dublin Maker Faire post). To make this possible the keypad-adapter would have to double up as an ir-adapter. But this required a change of circuit layout.

The keypad has five wires; 3 output, 1 led, 1 ground. The ir-detector has four wires; 1 output, 1 led, 1 ground, 1 power. The adapter has five slots. But two of them are pins 0 and 1 (Rx & Tx) and I had trouble getting them to work consistently. So to fit everything in I decided to move the power and ground lines out to their own adapter. But where was I to find a two-pin breakout board? They come in large, small (used for the existing adapter), and that's it. *brainwave* I remembered a set of empty LED boards I hadn't gotten around to using.



And sure enough, two separate connections, just add headers! I pulled out the existing stitching and stitched the new layout in. The power lines are actually run along the back in channels of bias-binding for insulation because the whole thing is so crowded at this point.



Turned it on, fixed up the code (new pin numbers), adjusted the timing on the patterns, and tried my hand at interrupt coding. However, before I could finish it up, my top needed to go off with [twitter.com profile] Jeffrey_Roe and [twitter.com profile] PartFusion to NY MakerFaire to represent tog, so development of new features was promptly abandoned, to be continued once it returns. (Although, I hear it was a bit wet, so I expect my top probably stayed in somewhere nice and dry.) *edit* Spot the LED top. But now I have a definite list of things that need doing, and then it will actually be finished!

Part 1 | Part 2 | Part 3 | Part 4.a
chebe: (Default)
Bear with me, this is going to be a long post.

This Saturday just gone, July 14th, was Dublin's first Mini Maker Faire! It was held in the Science Gallery and on the Physics Lawn of Trinity College. I was there as a part of TOG, the Dublin maker/hacker-space. It was a fantastic day. So many people showed up who already knew a lot and came up with interesting questions and ideas. Some people were just wandering through Trinity like they do every weekend and were a little confounded to find us there. Yet others showed up wearing ESOF lanyards! I'm sad I didn't get to see much of the other makers or exhibits, things were just so hectic! It certainly seemed like everyone was having a good time.

Maker Faire )

TOG's new tshirt )


Projects

Arduino IR receiver )

LED matrix top )

Constellation Quilts )

Well, I fairly collapsed with exhaustion about 4pm (missing the after-party and everything), but up until that point it was a great day and I'm already looking forward to next year!
chebe: (StarryNight)
Take one Lilypad LED-matrix top (you thought I'd forgotten, hadn't you?), add one SparkFun Wearable Keypad, and voila! You get one fun interactive top!

The devil's in the details )

It's all controlled by the push-button. Initially all LEDs are off.
- Push once; all LEDs are on.
- Push twice; you get the random LED twinkle pattern.
- Push thrice; you get into keypad controllable mode (denoted by the keypad lighting up). You press the centre SparkFun-logo button to clear the board and pick a random starting LED. Then you can use the four directions to draw in lights.
- If you press the push-button a fourth time, you stay in the keypad mode, but the timing changes and the pattern becomes a chase-sequence.
- Pressing the push-button again brings you back to the beginning, with all LEDs off. (But so long as you don't turn off the battery, your pattern is still kept in memory.) Here, have a look.



If you happen to be at Darklight next weekend, come find the tog guys, and you can have a go yourself :)
chebe: (Default)
Remember part 1, with the 3x3 LED matrix? That was practice, for this, a 7x7 matrix, on a functional, wearable, piece of clothing.

Lots of text, pictures, and a couple of videos. )
chebe: (Default)
I can't help it, I think LEDs are pretty. So what could be better than a tshirt with 49 of them? Well, there's a lot to figure out before I get that far. Let's start with a more reasonable number, say 9, that's a 3x3 matrix. Yes, that's doable. But let's not make it too easy, let's try using the sewing machine, and user input. Okay, ready?

Details, pics, and vid. )

Things I Learned:
1. That to use 4-ply conductive thread in a sewing machine it needs to be in the bobbin.

2. That your choice of fabric is very important. If it is thin/light you need to skip a couple of stitches at the point where two traces cross, to prevent possible shorting.

3. That I can use user input through the computer to affect Arduinos through Serial.read().
Page generated 2017-Oct-23, Monday 12:46 am
Powered by Dreamwidth Studios