Below given is Relay Driver Circuit to build your own Relay module: Circuit Diagram and Working: In this Arduino Relay Control Circuit we have used Arduino to control the relay via a BC547 transistor.

Just power the relay module using the Vcc and ground pin and connect the signal pin of the module to pin 3 of the 555 timer. Connect the Common (C), Normally Open (NO) and the Normally Closed (NC) ...

Circuit Diagram: Relay module: Connect the IN pin of the relay to a GPIO pin (e.g., D1 or GPIO5). ESP8266 or ESP32: Make sure the relay module's VCC and GND are properly connected to the board.

Fig. 3: Circuit diagram of the voice-controlled home automation system Bluetooth module HC-05 transmits and also receives data serially via Board1 that can be read by the microcontroller (MCU). A ...