Welcome to my quick review of an inexpensive 2-channel 5V relay module controlled via RS485 bus utilizing Modbus RTU protocol. As claimed by some online sellers, this easy-to-get Modbus RTU 2-Channel ...

It is very easy to build an “SMS-controlled relay” with the help of a cheap GSM modem module and a small microcontroller board. Here, I’m using the SIM800L and Arduino Nano V3 to develop a nifty ...