This program converts 12-bit samples from the Maxim 1270 A/D chip into a MIDI message, using the aftertouch command. The first 7 most significant bits are transferred in the first MIDI parameter to the aftertouch command which is traditionally the MIDI key number. The 5 least significant bites are transferred in the second MIDI parameter byte of the aftertouch command.
Here is a schematic of the circuitry connected to the Basic Stamp IIsx for use with this program:
