The MEGA 2560 is designed for more complex projects. With 54 digital I/O pins, 16 analog inputs and a larger space for your sketch it is the recommended board for 3D printers and robotics projects.

All four relays are connected with Arduino at 8,9,10 and 11th pins (In1, In2, In3, and In4), and 1 12v adapter is used for powering the circuit. We have connected 220VAC bulb at the terminal block of ...

Bluetooth module HC-05 transmits and also receives data serially via Board1 that can be read by the microcontroller (MCU). A relay is used here to control only one appliance, though you can use a ...