Space communications require line-of-sight. So we developed the Cosmoneer to use infrared to communicate to impose the real challenges of space communications. The Serial IrDa board can also be used for high altitude ballooning, where low power wireless communications is needed, but the inclusion of another RF device will cause issues with other onboard payloads.
It uses an industry standard protocol named Serial IrDa (version 1.3.) Communication is supported at a range up to 1m, or 3.3 feet, +/- 15 degrees which yields a .53m (1.75 foot) diameter cone when separated by the maximum distance.
We hardwired the MCP2120 Infrared Encoder/Decoder IC to Hardware Baud Rate selection only (set via the MODE pin.) To accomplish this, the MODE pin is tied to the RESET line which is exposed via the header connection, and both must be held at logic HIGH for normal operation. If you are using a micro controller to communicate with the MCP2120, you can connect the reset line from the micro controller to the board’s RESET connection. Pulling this pair LOW effectively reset’s the IC.
To activate the chip to perform active communications, the ENABLE line via the header connection must be held at logic HIGH. With the IC disabled, it enters low-power mode and consumes very little power.
Before using your Serial IrDa board, you will need to decide what baud rate you will be communicating with and using a soldering iron, carefully bridge the jumpers to the side indicated for each jumper listed in the jumper settings chart below:
The board is designed with hacking in mind, so we used 0805 sized SMD parts for those interested in making mods straight to the board.