Line Follower

Components Required

• caster wheel

• Metallic chassis

• Motor Driver L293D

• LCD(16*2)

• Servo Motor

• PCB

• Crystal Oscillator 20MHz

• Resistors 10kΩ,1kΩ

• LEDs PIC 16f73, 28 pin bar,16 pin bar,8 pin bar

• 7805 Voltage Regulator

• Capacitors - 470µF,100µF,0.1µF,22pF

• 2 tyres and

• IR sensor pair

• LM324

• Operational amplifier

The line following robot is programmed to follow a dark line on a white background and detect turns. The core of the robot is the PIC 16F873 microcontroller. The speed control of the motors is achieved by the two PWM modules in the µC. The direction control is provided by 2 I/O pins. The H-Bridge motor driving/control chip takes these signals and translates it into current direction entering the motor armature. The sensor is an array of 7 IR LED-Phototransistor pairs arranged in the form of an inverted V. The output of each sensor is fed into an analog comparator with the threshold voltage These 7 signals (from each photo-reflective sensor) is given to a priority encoder, the output of which to the microcontroller.In this system, each back wheel has a dedicated motor while the front wheel is free to rotate via caster wheel.