Send a pulse on TRIG, time the echo on ECHO, divide by the speed of sound. It is the first sensor most people get working, and it stays useful long after that.
Specifications
| Range | 2 cm - 400 cm |
| Resolution | ~3 mm |
| Beam angle | 15 degrees |
| Interface | TRIG / ECHO digital pins |
| Operating voltage | 5 V |
| Current draw | 15 mA |