This is a low-level 5VDC 2-channel relay module with a standard interface that ... 5V to JD-VCC for powering the relay section. If so, remember to connect the VCC pin to 5V of the Arduino board to ...

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 ...