I have a student project where I have to use one two wires to transmit both power and serial data between a Raspberry Pi and an Arduino.
The project uses a 120VAC to 24VAC transformer. The 24 VAC is fed down a set of train tracks... The train has a microcontroller (Arduino) that must receive serial data, taken from the 60hz power rails, but disregard the 60hz "noise". The input serial data is fed into the rails by a Raspberry Pi serial output.
Does anyone have any ideas on:
1) inputting the serial data into the 60hz rails from serial +3.3V... and
2) getting the serial data back out and into the Arduino???
Would I want a notch filter to zap just the 60 hz? A highpass / bandpass filter for everything above, say 1khz? OR, a set of optical amps... one for amplifying EVERYTHING... and the other for selectively filtering out the 60hz and inverting the signal, combining it back into optical amp #1 to cancel it?
Any help is appreciated!
--Quantboy