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Servo calibration

Time: 11:10 AM to 11:35 AM
Before your robot can move accurately, you need to calibrate its servos. Calibration tells the software where “zero” is, so that every movement command starts from a known, centered position.

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Run the calibration script

cd ~/picar-x/example && sudo python3 servo_zeroing.py
This script sets three servos to their mechanical center:
  • Steering servo - controls which direction the wheels point
  • Camera pan servo - controls left/right camera rotation
  • Camera tilt servo - controls up/down camera angle

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Visual check

After running the script, visually inspect your robot:
1

Check the wheels

The front wheels should point straight forward, not angled to either side.
2

Check the camera

The camera should face directly ahead at a level height, not tilted or rotated.
3

Adjust if needed

If any servo is off, adjust the trim values in the calibration config and re-run the script until everything is centered.

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Why calibration matters

Without calibration, every movement command is relative to an unknown starting point. If the steering servo thinks “center” is actually 10 degrees to the left, then a command to turn right will not produce the expected result. Calibration fixes this by defining a reliable zero point.