Blueduino-RC4

Bluetooth 4.0 LTE Remote Control for Zoom H4n Recorders (c)2014 Greg Schoppe CC-Attribution

for Blueduino 8Mhz/3.3v or similar Arduino compatible board that supports 3.3v power and serial, and Bluetooth 4.0 LTE.

NECESSARY CONNECTION:

Connector: 2.5mm (3/32") TRRS Jackplug
Pinout:
  Tip     Pin1/RX1
  Ring1   Pin0/TX0
  Ring2   GND
  Sleeve  VCC(3.3v)

IMPORTANT NOTES:

1. You MUST use a 3.3v Arduino variant and power it from the 3.3v connection with the H4n. You WILL destroy your H4n if you power the board with 5v or connect the 3.3v line to an unregulated power source.
2. This Sketch requires the use of the Arduino's Standard Serial Connection, making debugging difficult. It could be modified to communicate with the RC4 using a second instance of SoftwareSerial on Pins 8 and 9, but might have trouble with concurrent reads blocking each other.