Infrared sensor modules need to be calibrated for the following reasons:

• The environment may be too bright for the sensor to actually detect anything
• Due to changes in environmental parameters, we may need to calibrate them to suit our needs

Let us consider a line follower robot under two sets of conditions:

• In a normally lit environment (indoor)
• In a sunny environment (outdoor)

When the robot runs efficiently in an indoor environment under ambient light, it is not necessarily true that it will do the same outdoors. The reason is that the sensors are infrared and in a brightly lit environment, especially in sunlight, it's harder to detect. Now, how do we calibrate the sensors? Every sensor module has a potentiometer that controls the sensitivity of the sensor. This potentiometer needs to be adjusted according to the surroundings so that you get appropriate readings.

Now, when you are dealing with robotics, keep some code handy, because it might be required. Similarly for calibration, we follow very simple steps.

Let us consider a simple line follower use case. We need to follow a black line on a white track. The steps are as follows:

1. Place the robot or the sensor in the ideal position (ideal position stands for the position where your robot needs to be, that is, at the center of the line).
2. If the robot is not yet constructed, then cover your sensor with paper and hold it at or about 2 cm above the track.
3. Now check the values of the sensor with the code to be shown in the following steps.
4. There should be a stark difference between the sensor that is above the white line and the sensor that is above the black line. If you have both the sensors above white line then the values should be exactly similar else adjust the potentiometer.
5. Similarly, carry out the process by placing both the sensors over the black line.
6. Carry out the entire process again if the environment or, more precisely, the lighting conditions change.