Arduino is a development platform based on a free hardware electronic board that incorporates a re-programmable microcontroller and female pins to connect sensors and actuators. Arduino boards commonly include power inputs, pins for voltage, ground, analog, digital, and PWM signals, a reset button, power and TX/RX LEDs, the main integrated circuit, and a voltage regulator. Popular Arduino boards include the Uno, LilyPad, RedBoard, Mega, Leonardo, and shields that can be added to boards.