USB audio S/PDIF output
This project uses the microcontroller PIC32MX270 to read audio data from an USB host and to output a corresponding SPDIF audio stream over an SPI port. The SPDIF bitstream is generated in software. As a consequence, no special encoder chip is needed. An optical SPDIF transmitter can directly connected to the SPI/I2S port of the microcontroller.
The binary image for the microcontroller can be compiled with the ChipKIT toolchain. Simply change to the src directory and type make. It should also be possible to use the XC32 toolcain (requires chaging the first few lines of the Makefile); but this has not been tested.