It's only for fun, for the technical part. I remind you that even if you detect the police laser, it is because it has already taken your speed. so please avoid me, it's forbidden, it's not good etc ...
The police use different laser guns to measure speed, which all work in the same way. Sending a laser pulse and measuring the reflection.
The goal being to detect the laser and count the number of pulses to identify the type of laser gun.
Here is what I found on the net:
- Ultralyte Rev.1: 100pps
- Ultralyte Rev.2: 125 pps
- Stalker LZ-1: 130pps
- Kustom Prolaser3: 200 pps
- Laser Atlanta : 238pps
- Laser Atlanta stealth mode: 238pps (2 pulses fire followed by 5 missing pulses)
- Jenoptik Laveg: 600pps
- Kustom Prolaser1: 380pps
.These laser guns use Laser diodes with these characteristics:
- wavelength: 905nm
- Average power: ~50-120uW (microWatts) (for eye safety)
For obvious security reasons and in order not to burn the eyes of offenders, the laser beam is very weak, so the receiver will have to be ultra-sensitive to detect it and only in the 850-950nm wavelength to avoid interference. especially over long distances.
I found on the net a very amplified circuit for a SHF203FA phototransistor (attached).
Is this circuit ok? and you think we can couple it to an arduino to count the laser pulse