Hello MMDers, I've developed and built a system of MIDI wireless
using the Arduino microcontrollers and 915 MHz radios.
It is a one-way, one-to-one link between a MIDI player (a computer
or laptop MIDI file player) and a MIDI instrument like a player
piano or organ. It requires less than $50 in components.
If anyone wants to try the implementation, I can give some support.
It was already done by some. More information about the hardware and
software is here: http://forum.arduino.cc/index.php?topic=253382.0
Vimeo video: https://vimeo.com/99947862
[ A schematic diagram of the microcontroller plus radio is at
[ http://www.anarduino.com/miniwireless/#schematic -- Robbie