Low cost Radio Controlled (RC) car with speed controller

Abstract

Nowadays, microcontrollers play an essential role in our daily lives. For an electronics hobbyist, microcontrollers will offer a wide range of possibilities that would be otherwise unreachable. A radio-controlled car (R/C car) is a powered model car driven from a distance using a radio control system. Inputs from a transmitter are sent to the car's onboard receiver. The receiver interprets the radio signals and sends electrical pulses to the motor. The purpose of a motor speed controller is to take a signal representing the demanded speed, and to drive a motor at that speed. The speed controller circuit presented here is designed to drive a simple cheap DC motor using ATMEL AT89S52 microcontroller. A very popular circuit for driving DC motors is called an H-bridge. The project circuit design use L293D chip as it has a built-in H-bridge. After the circuit design is implemented, the RC car speed can be controlled to desire speed. It has a variable speed and the speed level can be control by user.