It's been another few weeks of traveling and client work so I haven't had any chance to tinker. Apologies to those subscribers expecting the frenetic pace of my SQL blog - ain't gonna happen. I'm at home for a few weeks now though, so should have spare cycles to get back to the Arduino.
This week I decided to build a kit, as I didn't have time to get stuck into something more intellectually challenging. A while ago I'd ordered a set of 4 interactive light panel kits from Evil Mad Science so I chose to make one of those (I've also got an RGB Peggy 2 board that I'm itching to make!).
I'm very impressed with the kit - the instructions are *excellent* - totally suitable for a novice, but easily digestable by someone more advanced without being annoyingly simple. The packaging is great too - with all components packed and labeled separately - not something I expect, but a nice time saver.
The kit took me about 4 hours of soldering and neat lead-snipping to put together. I powered it on and it worked first time. However, it's supposed to work in the dark and I couldn't get anything out of it. The board looked perfectly put together so I contacted Evil Mad Science. Windell replied within 90 minutes with some suggestions. I replied that I've got a degree in electronics so talk techie - smileys ensued and we troubleshooted (troubleshot?). I'd hooked up a spare IR LED and shown that the phototransistors were working, but obviously the IR LEDs on the board weren't - with only about 10mV foward voltage across each. The whole IR LED circuit has 24V through it, so something was sucking down the power. I traced it to a broken IR LED with very high resistance both ways, and taking 18V - no wonder it wasn't working. I swapped out the broken LED and put in another, and hey presto! Great technical support!
Great kit to put together and I'm going to build a wall tile to hang in the house somewhere!
Here's a link to a 25sec video I shot on YouTube: http://www.youtube.com/watch?v=51dUYjEgTi8
Here are some photos (click for larger images):
Left: kit contents for one board. Right: PCB (*really* well produced).
Left: ready to start soldering. Right: Completed board ready for testing.