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 ...

Those aren’t here. Next, a 5V relay is wired between the output of the timer chip and the ground rail, which runs on 5VDC. When the timer output is high, it will typically be somewhere between 1.2V ...