Ultrasonic rangingUltrasonicranging

A simulation of how the part behaves — not a recording of mine. Bench photos go in the evidence below.

1. 01 · Ping→

   A shout you can't hear

   Give the HC-SR04's trigger pin a short pulse and it fires a burst of 40 kHz sound — far above anything you can hear.

2. 02 · Echo→

   The width of a pulse

   Its echo pin stays high for exactly as long as the sound takes to bounce back. That pulse width is the entire measurement.

3. 03 · Distance■

   Divide by two

   Sound travels about 343 metres a second. Distance = echo time × 343 m/s ÷ 2 — halved because the sound went there and back. Good for roughly 2 to 400 cm.

What I actually did with it

• 01Used for distance on the bench

[ADD — what you measured, and on which board]