Simplemodbus -

void loop() { modbus_update(); // listens and replies to Modbus requests } #include <SimpleModbusMaster.h> unsigned int readRegs[10]; unsigned int writeRegs[10];

void setup() { // Modbus slave ID = 1, RS485 (or serial) on pins 2,3 (DE/RE) modbus_configure(9600, SERIAL_8N1, 1, 2, 3, holdingRegs, 10); } simplemodbus

void setup() { modbus_configure(9600, SERIAL_8N1, 1, 2, 3); // master has no slave ID } void loop() { modbus_update(); // listens and replies

Here’s a solid write-up for (likely referring to the Arduino/library context), structured for a GitHub README, documentation page, or project showcase. SimpleModbus SimpleModbus is a lightweight, easy-to-use implementation of the Modbus protocol designed for microcontrollers like Arduino, ESP32, and other embedded systems. It strips away the complexity of full Modbus stacks while retaining reliable communication for RTU (RS232/RS485) and sometimes ASCII modes. void loop() { modbus_update(); // master uses this

void loop() { modbus_update(); // master uses this to send pending requests