RDS modulator for FPGA
This code comes complete with FM transmitter. No external components are needed, not even antenna if FPGA is 1m close to the receiver.
Tune FM radio to 107.9 MHz (or change freq in main.v) and RDS example text "TEST1234" should appear.
There's a simple audio tone synth, pressing buttons will play notes.
Currently MONO only, STEREO is planned but not yet ready.
Tested with ULX2S, porting to other FPGAs should be very possible.
Credits:
Marko Zec, svirajfm FM radio lab excercise for ULX2S, fm transmitter and audio midi synth copypasted
N. G. Hubbard RDS transmitter for PIC microcontroller DBPSK waveform copypasted http://www.anotherurl.com/library/rds_formulae.htm
Christophe Jacquet, F8FTK RDS for Raspberry PI Bit message generator in C code copypasted from https://github.com/ChristopheJacquet/PiFmRds
Oona Räisänen OH2EIQ RDS receiver "redsea" for RTL-SDR used as receiver and for debugging https://github.com/windytan/redsea