We had another Open Day today. A slightly more select gathering than the last jam-packed one. I showed off my Windows Phone remote controlled coloured light to good effect, and then I went on to mention to folks that, for some reason, I had bought one of these:
It is a whacking great big display panel, like the ones you see on the side of buildings. It is 7.5 inches across and contains 1,024 RGB leds in a 32x32 matrix. I've been playing with light panels for a while, and this one is awesome.
The only snag is that, unlike the Adafruit Neopixel devices that I'm familiar with, on this one the led's don't remember the colour they've been asked to display. The computer controlling the panel must constantly light rows of leds in turn. repeatedly switching them to the required colour for a while before moving on to the next. If you do this fast enough you get the appearance of a steady image. This is hard work for the controlling computer, one panel would pretty much tie up an Ardunio completely. But the good news is that there are a couple of really interesting controller chips that I've been looking for a reason to play with which should be able to drive this, and more, panels.
First up is the Parallax Propellor, which should give me eight parallel processor cores, one of which should be able to drive a single panel. I've found a device on eBay and I'm looking forward to having a play when it arrives.
The other (and much more interesting) device is brand shiny new. It is from XMOS, a company in Cambridge, and builds on expertise from ARM and Transputer to deliver a multi-cored device which has as its focus high performance, zero latency and total determinacy. In other words you can be sure that you will get processing power when you need it, and you can be absolutely sure how long something will take to complete. This, coupled with the raw power that is on offer would seem to make it perfect for driving these panels.
You can pick up development kits (with a processor, some inputs and outputs and access to the hardware) for around ten pounds from Farnell in the UK. The board looks quite spiffy and if you are into embedded you really should get one to play with I reckon. The XMOS web site makes it really easy to buy the board if you are in the USA, but the UK links are more tricky to track down. You can find it on the Farnell site here.
The funny thing is that I mentioned my ongoing obsession with bright coloured lights and this was seen to be a good thing by folks present at the open day. My ultimate plan, a coffee table with four of these panels in the surface, was actually lauded as a good idea. We shall see.....