Finally settled on the v1 Controller system that we’re taking to Critical Northwest. It turned out to be quite a bit more straightforward than the initial build. In the photo below, you can see the Simon controller printed circuit board. It’s one-sided, so the traces are facing away from us. In the lower right, there’s an Arduino Mega. Why a Mega? Well, the prices on these have come waaay down ($20), and they feature four hardware serial ports. One of those ports is connected to the Xbee Series 1, which you can partially see in the upper left. That hardware serial turns out to be pretty important. While a serial port can be emulated in software, we’re also hooking an interrupt service routine to analyze the frequency being played on the speaker. If we were to try to do both of these things (software serial emulation and frequency analysis), that’d be hard to pull off. The timing falls apart, and the serial link is disrupted. That would lead to the art sculpture and controller coming of of sync, which we don’t want.
I may still add a lithium polymer battery to replace the 2x D cells. I had this set up in in the intial build, so I can probably move that hardware over. I won’t do so for Critical Northwest, however–“one in the hand is worth two in the bush.”