I have no experience about serial communications, with that being said; I have two circuits isolated from each other and each have a ATMEGA8 reading a voltage on their ADC.
I want one of them to send ADC data to another without having a common ground. I know that I can do it with a Bluetooth or Wi-Fi "module" but I'm looking for an easier way, like maybe with an optocoupler but again I'm not aware of the limits.
- What's the cheapest and simplest way to do this? and basically how it's done?
There's a lot of information about making two Arduinos talk to each other but I couldn't find much information/documentation on isolated communications.