Extra sensors have turned up, along with the perspex samples. It seems to come in standard 3mm or 5mm sizes. Having tried both I think I'll go for the 5mm; it's nice and chunky and isn't going to bend any, so I've passed that request on to the joiner.
Both thicknesses seem to work similarly with the sensors, which is that as long as it's really close it doesn't seem to affect them much, but if you move it just a few mm away from the surface the readings go off. Reflections or something I guess, so I'll just have to make sure they're fitted closely against the lid.
After starting to look at the MIDI over USB library for the Mega it turns out that it doesn't support it natively, but it sounds like there's a workaround using
this library so I'll give that a go. Or I could stick to using the MIDI shield, and it would be quite nice to have proper MIDI in/out, though the case won't be deep enough to support the stacked boards so I'd have to wire them together side by side. Should be simple enough, though I'm surprised it's not easier...I'd have thought there would be common adaptors or cables or something for this but I haven't found any yet.
The Neopixels strip has also turned up; these look fun, and fairly straightforward. There are connectors either end for ground and power. One end has "data in" and the other has "data out" and I think you can just wire them up in series then address individual LEDs in the chain using a standard Arduino library. Going to need some solder to connect it up though; it's been a while, and after spending half an hour rummaging around in sheds and drawers I gave up and added it to the eBay list. Besides, I like getting these little envelopes turn up every day or two with components.
I've found that the Arduino maxes out at 200mA so it won't be able to power everything. The IR sensors take up to 30mA each, and individual Neopixels can apparently guzzle up to 60mA each on full brightness, though you could get away with a lot less. I'm thinking, maybe 20mA per pixel, 160mA per strip, 1280mA for eight; plus 240mA for the eight sensors gives 1520...so a 5V DC supply rated at 2A ought to do it. I'll do some experimenting with a breadboard.
