By "modulating the clock" I mean modulating the SoC base clock frequency (nominally 100 MHz, but increased to be a valid and unused FM channel, if decreased then the pi locks up) with the audio to make an FM transmitter. Hook up a wire to the clock output GPIO pin and you have an FM antenna. Lay it next to an old FM clock radio and you now have a clock radio that plays whatever you want. Make a cron job and forget it.
I’m certain it plays hell on software timekeeping. If you don’t have an RTC then switching to chrony and increasing the poll rate should help prevent potential clock error.
By "modulating the clock" I mean modulating the SoC base clock frequency (nominally 100 MHz, but increased to be a valid and unused FM channel, if decreased then the pi locks up) with the audio to make an FM transmitter. Hook up a wire to the clock output GPIO pin and you have an FM antenna. Lay it next to an old FM clock radio and you now have a clock radio that plays whatever you want. Make a cron job and forget it.
https://github.com/pimylifeup/fm_transmitter