Visitor counter

A PIR motion sensor with OUT on GPIO4 (power it from 5 V). Count visitors: each time OUT goes high, add one and print the new total:

Visitors: 1

OUT stays high for about 5 s after each visit, so print once per visit, not once per loop. The test sends visitors at 1 s, 10 s and 19 s.

Tip: gpiozero's when_motion callback runs once per rising edge.