An idea... that was fruitless

A project log for Bicycle Dashcam

Bicycle Dashcam with License Plate Recognition (ALPR)

richard-audetteRichard Audette 02/17/2020 at 21:070 Comments

I have an old Canon S90 point and shoot camera that I haven't been using. This weekend, I thought I'd try to see if I could use it for this project..  It isn't rugged, but thought it might be fine for taking this project a bit further, as it takes great photos, and if I could find one, Canon did make a rugged waterproof case for it.  It also has image stabilization, which should help with getting useable photos on my bumpy ride.

I looked at how I might be able to control it, and download photos for processing.  First, I looked at PTP, the protocol for downloading images from cameras.  PTP allows for telling the camera to take a picture, and then download it.  I tried an PTP Node library, it didn't work, and then I tried using a command line PTP control tool called gphoto2. Gphoto2 worked great for downloading photos from the command line, but wouldn't instruct the camera to take a picture - it turns out, my S90 doesn't support that feature (although its predecessor, the S80, did!).

Then I thought, I could take regular pictures on a timer, and then download them for processing.  I had done this before using CHDK custom firmware for Canon cameras.  CHDK allows you to do all sorts of things with your camera that it can't do out of the box, including automation and scripting.  I thought I would use a pre-written script to take a photo every 10 seconds, and then download it with gphoto2.  But as soon as I connect the camera with PTP/gphoto2, the script stops.  So I'm back to looking for a camera, or camera module, that I can control from a Pi & can take useable photos in a high-vibration environment.