ABSTRACT
The desired functionality of the Arduino UNO board is controlled by the application program developed by the user along with sensors, input devices, output devices, and actuators. So the knowledge of different types of sensors, input devices, output devices, actuators, etc. is very important if someone wants to develop an Arduino-based system.
This chapter deals with the construction and working principle of various sensors, input devices, output devices, and actuators. The readers will learn in this chapter the working principle and function of various pins of output devices such as light-emitting diode (LED), seven-segment display, and liquid crystal display (LCD). The readers will also learn the working principle and function of various pins of temperature sensor (LM35), humidity and temperature sensor (DHT11), light-dependent register (LDR), touch sensor, smoke detector (MQ2), rain detector (FC-07), ultrasonic sensor (HC-SR04), and soil moisture sensor (YL-69). An in-depth description of the Bluetooth module (HC-05) and GSM module (SIM 900A) is also given in this chapter. This chapter also deals with the working principle and function of switch, keypad matrix, potentiometer, analog-to-digital converter IC, motor driver board (L293D), and relay board.
