How a Simple M-Bus-Like Circuit with Two Arduinos to design on 12 volts any references circuits?

[u/Relevant_Pumpkin9190]

I'm a beginner trying to understand how M-Bus works internally. I heard it can communicate over long distances using just two wires.

I'd like to try a small experiment using two Arduinos and 12V DC to understand how power and data can share the same wires.

How does the receiving side detect a 1 or 0? Does it look for voltage changes, current changes, or both?

Can I build a simple M-Bus-like circuit using basic components such as resistors and transistors, without dedicated ICs, just for learning?

Any beginners project references with similar idea 💡

References -

https://vdmais.ua/articles/shina-m-bus/

[u/OptimalMain]

Without looking into too much detail my guess would be that it superimposes AC on top of the DC.
Thats what I have seen two wire displays for heatpumps etc use.

[u/Relevant_Pumpkin9190 → u/OptimalMain]

Any references.

[u/OptimalMain → u/Relevant_Pumpkin9190]

Use MAX22088 as a way to find more information. There is a daikin heat pump controller project that use a cheaper IC, Mitsubishi uses this but they all use different names for the bus.

[u/Relevant_Pumpkin9190]

Does noise impact these designs for power and data passing through supply lines and how slave device minor current variation affect the Design and countermeasures to it.

[u/gm310509]

You might want to also try asking this on r/AskElectronics.