I'm making a project which involves powering three high power LEDs in a bike light with a constant current boost converter (mounted elsewhere on the bike). I can either have a two or three pin connector going to the bike light. I'd prefer two pins, because it means less wiring, and I'm already doing a custom driver PCB and a custom PCB that goes in the bike light itself. The LED driver changes current with a button press input.
How could I send a button press over the power cables for the bike light? So far, I was thinking of a 555 in the bike light with an AC coupled output, going to the high side cable and adding a 50khz square wave to it when the button is pressed. On the other side, I could sense it with an AC coupled peak detector and a comparator going to the MCU. Since the LED driver is constant current, I'd put a 500ohm or so resistor so the 555 gets power when the light is off.
Is this going to work?