Lab 3 — LiDAR / ToF Distance Sensing

Duration90 minutes

Depends onLab 2

MilestoneReliable obstacleDetected() + sensor test data

StatusOutline — to be written

Practical focus

Mount the distance sensor; measure known distances; determine useful range and field of view; implement basic obstacle detection.

Class 1 laser product

The scanners are Class 1 and safe in normal use. Do not open a housing or run a unit with a cracked case — report it instead.

Objectives

1. Mount a distance sensor rigidly to the chassis.
2. Calibrate readings against known distances.
3. Determine the sensor's useful range and field of view experimentally.
4. Write a dependable obstacleDetected() function.

Procedure outline

TODO — expand.

1. Mount the sensor. Height and tilt matter more than students expect — a sensor aimed slightly down will see the floor as an obstacle.

2. Place a target at known distances and record readings.

   True distance	Reading 1	Reading 2	Reading 3	Mean	Error
   10 cm
   25 cm
   50 cm
   100 cm
   200 cm

3. Find the near limit and far limit where readings become unreliable.

4. Sweep a target sideways to map the field of view.
5. Implement and test obstacleDetected().

Make the threshold a named constant

const int OBSTACLE_CM = 30;   // tune this, don't scatter magic numbers

You will change this value in Labs 5, 9, and 10. Give it one home now.

Deliverable

Reliable obstacleDetected() function + sensor test data.

Include the distance and field-of-view tables, and state the range over which you trust the sensor.