- 01Ruler distance
- 02Recorded echo
- 03Displayed zone
- 04Error notes
Use a ruler before using confidence
Mark several positions on a desk, use a flat target, and record ten readings at each position. Keep the target angle and sensor placement consistent. Report the spread and any unknown readings rather than retaining only the best measurement.
If you have only run the desktop tests, this is where the physical kit becomes useful. The course and logic tests remain free; a kit is a convenient parts bundle, not a requirement to learn the code.
Investigate one boundary
Move slowly around the close threshold, first approaching from far away and then retreating from close range. The different transition distances demonstrate hysteresis. Compare serial text with the actual LEDs so a wiring mistake does not masquerade as a policy bug.
Record the board support version, sensor module, pin map and upload settings. Physical observations are your evidence; no supplied software test can establish the acoustic behavior of your particular setup.
Try it
Change only the target surface or angle and repeat the experiment. Explain why a missing echo is not automatically evidence that an object is very far away. Leave invalid readings visible in your notes.