The +5V supply line (VCC) of the module is linked to the 5V line of the Arduino. GND of the module is the common (0V) connection. The digital signal output to be detected (usually marked as DO in the ...

[Joseph] wrote in to share this home automation system he’s working on as a college project. He calls it the Room Engine and the house-side of the hardware is built on top of the circuit you … ...

If so, remember to connect the VCC pin to 5V of the Arduino board to enable the control input pins IN1 and IN2. Also note at this point that, if you want perfect galvanic-isolation, do not link ...