@peergum Not sure which specific code you ported your ModbusMaster one from (you said 4-20’s on the Github), but can it also be used as a Slave? I browsed through the code and don’t see a way it can. Was just curious if the original code has a Slave version as well that can be easily ported.
Hope you’re enjoying your trip and made it to the next country…in El Salvador, Costa Rica, Nicaragua now?
EDIT: Got @peekay123 's version working. Had to add a second TXEN to this line at the start of the code:
Modbus slave(2,1,TXEN, TXEN); // Slave @2, Serial1 TX/RX pins, RE/DE connected together
In setup, also had to add this for some reason. It would not work without: