Lunchtime RTLSDR
I want to use my iPad to listen to 101.5 FM. Before you mention that I could find the online stream, and yeah, I know that's a thing, that's too easy.
This is the Raspberry Pi 4 running headless, displaying it's IP and wifi SSID, and connected to a Software Defined Radio (the silver USB dongle) which is in turn connected to the antenna hanging in the tree. It's taking its audio from the FM channel and streaming it over the USB-C connection to the iPad over VLC.
The script looks like this:
#!/bin/bash
rtl_fm -g50 -f 101.5M -M wfm -s 180k -E deemp |\
sox -traw -r180k -es -b16 -c1 -V1 - -t flac - |\
cvlc - --sout '#standard{access=http,mux=ogg,dst=10.55.0.1:8080/audio.ogg}'
I would love to claim that I knew all of this, but I picked it up from a random google result that has since escaped my history, else I'd credit the writer. Whoops.
RTL_FM is telling the radio how to hit my station. Sox is taking the raw output of that and encoding it, and cvlc is my transmitter. On the iPad, I've asked VLC to play the stream from http://10.55.0.1:8080/audio.ogg and I get to hear my station.
It has some occasional issues where the audio drops, and I'm working through that. My intention is to also pipe my Pi's pulseaudio output to the same method so that I can hear what it's doing; that's my last impediment to running DOSBox with audio and without shenanigans using iPad Dev Mode and signing packages every seven days. Need to remember this link.