The RaspberryPI can use one of it's IO-Pins to transmit a stereo radio signal including RDS (https://github.com/miegl/PiFmAdv https://github.com/miegl/PiFmAdv).

The RaspberryPI can use one of it's IO-Pins to transmit a stereo radio signal including RDS (https://github.com/miegl/PiFmAdv https://github.com/miegl/PiFmAdv). It's probably illegal in most countries.