The functions are pretty straightforward.
- Wait for a sensor to trip
- Look for the opposing sensor to trip (while counting time)
- Print the speed
- Reset for next event
- 5 seconds for the time being
Error Catch Situation
- One sensor is tripped
- Auto reset after 70 seconds (1 MPH)
- It will report slowest possible speed
Basic Checkout of software
I manually pull a sensor line to GND at various intervals and got the responses captured below.