Erel I need a modbus library for B4R. I tested below library with Arduino Uno as Slave and Master. It works very well. It works both physical serial port and software serial port. I tested both with a RS485 converter connected Uno and USB-RS485 connected to PC. Can you wrap the library(ModbusRtu.h)? It also depends on softwareserial library.
https://github.com/smarmengol/Modbus-Master-Slave-for-Arduino
https://github.com/smarmengol/Modbus-Master-Slave-for-Arduino
