Looking for practical Arduino projects? This guide shows how to control a relay from your smartphone using an Arduino Uno — either via Bluetooth or Wi-Fi.

Connect the Buzzer to the Relay Module: Connect one end of the buzzer to NO (Normally Open) and the other end to COM (Common) on the Relay Module. Upload the Code: Open the Arduino IDE and create a ...

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 ...