DIY Laser levelling using webcam and laser level

[devmonkey]

Been a bit busy with other jobs, however I have been playing around with a raspberry pi version of this system. I took a PI zero W (with builtin wifi), a small TFT screen and an OV5647 (pi camera v1) and wrote some more software. This will form a simple standalone unit and addresses a number of the problems I was having with a simple webcam, specifically:

1. I access the raw camera sensor directly, read the bayer data and only use the red pixels. This removes a load of noise that was being introduced by the blue an green channels and interpolation. There is no interpolation done at all on the sensor using it this way which means I get the true intensity per (red) pixel. Pixel pitch is 1.4um and 1/4 are red so system resolution is 2.8um.
2. Vertical range is much improved around 4mm.
3. With lens removed there is no glass (or a very very thin glass maybe) over the pixel array unlike the VGA webcam which had about 0.5mm of glass which gave some diffraction patterns.
4. I put in an algo to dynamically adjust the exposure, this means I increase exposure until the detected gaussian starts to clip (sensor saturates) then back it down a bit. This makes things much more accurate and repeatable at varying distances from the laser source.
5. No more cables!

I printed a case for it today and mounted the camera to a piece of Aluminium, still need to fix it all together. It has a lipo cell on board that I salvaged from a dead rc pack, a usb charger / ups and lasts for about 3 hrs before needing recharging.






Cheers, Joe