This is a very affordable and simple to build speed trap based on the PIC 16C84 microcontroller. The goal was to use as few parts as possible while adding as many useful features as possible.

Newer versions of the 16C84 like 16F84 and 16F84A have been tested and they work well.

• Debug feature shows the state of the trigger inputs

• Programmable trigger on high to low or low to high transitions.

• Programmable light gate spacing

• Remembers the 16 last measurements

• Displays µs, ms, m/s or km/h (Other units by adjusting the trigger spacing)