analog_meter: Reads an AC-250 gas meter by monitoring the 1cfm dial

by Steve Devore [email protected]

I'm using a Raspberry PI, with the HQ camera (HQ because I needed a lens that could be mounted close to the meter).
It should work fine with the standard camera as well. The basic approach is to use opencv to find the correct dial,
and save the dial positions. I got more consistent results only looking for the dials one time, as opencv doesn't
exactly line up the circles between shots.

It then reads the top ccf dials for the starting position. Next, it looks at the 1cf dial and keeps track of the
position and revolutions to report the cumulative cubic feet used.

The take_picture method should return a cropped grayscale photo of the meter display. The example photo contains an
example of the source image of my setup.

For debugging, if it is run on a system without the camera, it will instead use a series of photos instead
The series can be created by enabling saveImages.