So in my spare time over the last few weeks, I decided to learn a bit about electronics. I've been toying with Arduinos for quite a while but I hadn't really devoted myself to a project, so I decided to make an LED wall… or at least try. An LED wall is essentially a small display made with a 2D matrix of LEDs. There are electronics kits you can buy which have them pre-built, and control them with arduinos like this: http://spod.cx/blog/driving_8x8_led_displays_arduino.shtml
Since I didn't know anything about how something like this would be created, I was basically learning from the ground up… so I learned about Charlie-plexing, which is a method to control a large number of devices with very few digital pins, and I learned about how digital pins have three modes instead of just two, which allow for special uses. I also revised the common mathematical theorem for controling LEDs with Charlieplexing to work with RGB LEDs, since the usual number is determined assuming that an LED only needs one ground wire.I ended up finishing it after a while… messed up once on the control scheme and altered the power lines to use 35 pins instead of the ideal 27 to control 100 RGB LEDs. Here is a test video of it running a marquee: http://files.64digits.com/SleepinJohnnyFish/VID_20130828_224021_528.mp4For reference, here is a clip showing the back (That's 400 solder points on the LEDs plus 36 on a small outer board for the resistors, all plugged into an Arduino 2560: http://files.64digits.com/SleepinJohnnyFish/VID_20130810_192331_552.mp4The next build I'm planning will be 32x32, built onto non-conductive wire spanning across a PVC pipe frame so that it can be hung up on a wall. For comparison, that's 1024 LEDs instead of 100, so it is significantly larger and more complex… and it will require an ideal connection layout to the Arduino to even fit the amount of digital ports needed…Wish me luck.
Oh Maine, this is radical. Don't know what to say except bravo on the soldering, looks like you did a hell of a job on the wiring. I can't imagine what the 32x32 will look like, but I hope you post some pics/video of the building process or at least the final build for us to drool over.
I always wanted one of those Arduino doohickeys to play with but I never could think of a project cool enough to justify it. I thought about building a synth out of one but would probably end up doing something super simple like a color-changing mood lamp instead. Not quite as exciting, but still an excuse to build something and program it from the ground up.Nice job. I've been following Tessel recently. I can't wait to get my hands on one. Like an Rpi but with nodejs built in
http://technical.io/If you want more freedom buy an AVR starter kit… I've been using one in class and it's totally worth it to have the customization if needed. And nice solder work.
My soldering work got a lot better on this project, for sure. I have never really done it. The next build is already looking to be a very different process. I'll get pictures for you guys and post it when it's ready.