Simply, it’s an Arduino library for communicating with Modbus slaves over RS232/485 via RTU (remote terminal unit) protocol. In conclusion, the Modbus 2-channel 5V relay module is a very useful device ...

A while ago, I made a simple yet expansible dual-channel firecracker/rocket igniter using an Arduino Uno microcontroller. This write-up is to share the design idea of that project. ... This is a ...