Introduction:
A line-following robot commonly known as LFR is basically an intelligent device that detects the line and follows the path on the floor. The path can generally be a visible black line on the floor, or it may be a white floor with a high contrast color. The basic principle of the LFR is based on the incident of light on the surface.
Line following robot is the most common and often the first robot-based project that students make in their academics. The basic working of the Line following robot is that it follows the black line on the white surface. It means the black line serves as the track of the robot. In this post, we have used an IC L293D to drive the two motors.
Hardware Components
The following components are required to make Line Following Robot Circuit
| S.no | Component | Value | Qty |
|---|---|---|---|
| 1. | IC (Motor Driver) | L293D | 1 |
| 2. | DC Motors | – | 2 |
| 3. | Battery | 5V, 10V | 1 |
| 4. | LED | – | 2 |
| 5. | LDR | – | 2 |
| 6. | Variable Resistor | 20KΩ | 2 |
| 7. | Resistor | 220Ω | 2 |
L293D IC Pinout
For a detailed description of pinout, dimension features, and specifications download the datasheet of L293D IC
Line Following Robot Circuit
Working Explanation
The basic principle of this robot is to follow a track made of black tape. The robot moves forward, left & right with help of motors which are driven by driver IC L293D. LDR1 and LDR2 are placed on the robot on the left and right sides respectively. The white surface reflects maximum light while the black surface absorbs maximum light. So when both the LDRs detect a white surface the robots move forward as the LDRs will allow voltages to pass (Low resistance on high-intensity light) on the EN1 & EN2 pins making the motor driver drive both the motors. When the left LDR (LDR1) detects a black line the light intensity on it is very less.
Due to this, its resistance becomes high which makes the voltage at EN1 zero making the left motor stop thus when only the right motor is running it automatically turns the robot to the left side. This procedure will be the same when LDR2 detects a black line resulting robot turning on the right making it follow the black line.
Applications:
- These robots can be used to carry and shift things from one place to another replacing conveyor belts in industries.
- It can be used to have a camera for surveillance and inspection in different areas.
