The Sensor unit is generating infrared light and when a runner runs in front
of it, it detects reflection from the runner and sends radio signal to
the Timer unit.
Components of FASTRun-R
The Timer unit consists of a radio signal receiver and a commercial stopwatch
Casio HS-70. The receiver receives the singals from the Start unit and
the Sensor unit and controls the stopwatch to measure time.
The Start unit makes an electronic pistol sound. Together with the sound,
it sends a radio signal to the Timer unit.
The Sensor unit is continuously radiating infrared light and
detects reflection from a runner. When the runner is detected, it sends
a radio signal to the Timer unit.