The components I ordered last week have come in!
These are the thumbsticks and clear caps (they came as separate orders and it took a while to get all the caps fitted right). There are 38 in this picture, one is wired into the Arduino, and David Glanzman has the other for testing with his PSoC. So we have 40 total, enough to start implementing the 'original' layout. Our end goal is the big, 58 note one.
We've been doing some thinking about the resolution of the ADC and the amount of data we'll be communicating. If we drop the resolution to 8 bits, we can fit the data in a single byte, and communicate the whole set of data for each sensor in 3 bytes (7 bit ID + one bit for indicating a button press, X value, Y value). If we kept the resolution at 10 bits, we would probably need 5 bytes per thumbstick (ID + button, two for X value, two for Y value). There are some tricks we could use to handle data more intelligently, like only sending data if the position of a thumbstick has changed, but we're generally trying to be on the safe side in terms of latency.
I've been working on some design stuff, and I think I have a decent concept for the enclosure. To get a better sense of the physicality of the instrument, I taped a bunch of hex grids to a cardboard box.
The lone hexagon in the bottom has holes for the pins on the bottom - you can stick a thumbstick into the cardboard and it stays mounted pretty well. I handed the box to my roommates and asked them to play with the thumbstick without giving them any information about how I intended it to be used. Their first instincts were to pluck at it with short motions, followed by a bunch of circles with the thumbstick pressed hard against the edge. Thinking about these natural or instinctive actions I've been designing a better mapping of motion to sound. The thumbstick is going to allow a smooth transition between different kinds of oscillators (all at the same frequency), with a filter gradually applied over a range of positions. It's hard to describe, but I'll post a video of the patch later on.
The other thing on my mind this week is Beta Reviews. The plan is to have several notes working in parallel, a fully drawn out design for the enclosure, and an example of a thumbstick with LED feedback. My review is on Thursday, so it's hustle time.