I recommend W5500 Ethernet Shield from RobotDyn) TTL to RS485 module: Download this repository (all *.ino files) and open arduino-modbus-rtu-tcp-gateway.ino in Arduino IDE. Download all required ...
the MA35D1 SoM supports dual Gigabit Ethernet, CAN FD, up to 17x UART, 16x analog input, etc.. and the SBC further integrates RS485 and RS232 terminal blocks, WiFi and Bluetooth, and optional 4G LTE ...
Here is my setup: Terminal shield + Arduino Nano + W5500 eth shield (RobotDyn) + TTL to RS485 module (HW ... file (arduino-modbus-rtu-tcp-gateway.ino) for how settings are stored in and loaded from ...