2015-04-14 - Acrylic Guitar Project
Read MorePickguard enlarged for MIDI pickup
Another problem was that the MIDI pickup (mounted on top of the pickguard) was less than a millimeter from the strings. I had to raise the action a bunch just to get them off of the pickup, but even so, they buzzed terribly. The answer: Cut away that section of pickguard, so the MIDI pickup can sit lower, on the guitar body itself
Etching PCBs is such a pain. This time around, I just opted for perfboard
The board takes 9V DC as input, which feeds three LM317's configured as constant current sources to send 350 mA to the red, green, and blue components of the two RGB LEDs. At the same time, a 7805 linear regulator (now replaced with a switching regulator equivalent) steps the 9V down to 5V DC to power the Raspberry Pi.
Trying to find a layout that works
I could probably get away with this if I'm really precise in my drilling, but at this point tests showed that the 7805 was getting very hot producing the 5V for the Raspberry Pi, and a heat sink doesn't fit in this tight enclosure. That's also wasting a good chunk of the limited power I've got available. So I decided to order a 5V switching regulator from Mouser to replace the 7805, and as long as I was doing that, I decided to order a larger enclosure as well.
Adding a 1/4" jack connected to the RPi's 1/8" audio output
I got the genius idea to use the Raspberry Pi as a synth as well, using FluidSynth, to eliminate needing to carry a separate keyboard. This hasn't worked very well so far though -- the synth sounds terrible and has very high latency -- so I'm abandoning that idea for now. But I have another use in mind for that 1/4" jack...