Laser Distance Measurment

[j.a.mcguire]

Would anyone have a recommendation on a microprocessor which would be suitable for measuring distance with light?  I wondered if there are ADCs which are stand-alone and could sample a photodiode with a nanosecond interval and fill a buffer when a detection is made which could then be sampled perhaps a few hundread times a second by a standard micro over serial?

Can this be done relatively inexpensively?

[lukier]

I doubt you would be able to find a microcontroller with  > 100's MSPS ADC and that's what one can usually find in laser scanners.

Laser scanners, if I remember correctly, use either phase measurement (like ToF cameras - http://www.ti.com/lit/ml/sbau219d/sbau219d.pdf) or some switched capacitor trick (like interpolator circuit in a frequency counter).

Probably the simplest and cheapest laser rangefinder is what is used in Neato vacuum cleaner - http://www.robotshop.com/media/files/PDF/revolds-whitepaper.pdf.

[f5r5e5d]

time of flight is tough without purpose built hardware

with of the shelf electronics speeds triangulation is popular with linear PSD or line element sensors

[amyk]

https://www.eevblog.com/forum/chat/how-does-laser-meters-work/

[tggzzz]

It is relatively easy to measure picosecond intervals - look for "time to digital" converters.

Before you spend too much time implementing it, you will have to consider how to distinguish photons from your light source from any other photons that happen to hit the detector.  Be very very careful with safety: 5mW (depending on wavelength and other things) is the maximium amount considered safe from a laser. Yes, you can easily get 400mW and 1W diodes, but they are definitely not safe.

If you use a powerful laser (i.e. >5mW) then you should protect those around you by looking directly at it the first time you swiitch in on - it will blind you and thereby stop your experiments before they damage innocent bystanders!