I got the PCBs yesterday and promptly set about assembling one. The really interesting part of that, of course, was whether it was possible to hand-solder the LFCSP ADXL335 accelerometer ("lead frame chip scale package" – who comes up with these names?).
It turned out it was, in fact, possible. The bottom pad is not soldered, of course, and even though I had made the pads longer to be able to reach them with the soldering iron it was still kinda tricky. But it worked. In first attempt, even.
And the little tumbler thingie works perfectly! (I'll post a video.)
But I need to tweak the firmware a bit. The sensor data from the accelerometer has quite a bit of noise and this results in too flickering light. So I will need to implement a filter of some sort. Either a moving-average filter or a simple low-pass filter. And maybe also some way of "snapping" to 0, 0.5 and 1 values in order to get more "clean" colors. Stay tuned…