Saturday, January 3, 2015

Scanner Unresponsive - What Next : ) ?

For the past 24 hours the scanner has not been functioning. Initially the top half of the image displayed the same repeating line of pixels, and a power cycle resulted in the device no longer appearing (lsusb) on the Pi

Both problems have separately occurred before. The former problem happened when the scanner was first buried. Dirt compacted too forcefully against the scanner meant the sensor was unable to complete a full pass, resulting in a similar image. The latter happened with the device reappearing after a day or two and several power cycles un/replugs, cause unknown.

So far the scanner has:
 - Spent ~6 months below ground
 - Captured ~17,000 images
 - Survived above-ground temps well below freezing

I'll wait a day or two more before going beyond power cycle and un/replugging the device : )

 - Automated uploading images to a remote server (Linode) and building daily videos.
 - - Next Step: Automate compilation of weekly and monthly videos, post online.

- Automated backup of the original images to Amazon S3 + file cleanup.
- - Next Step: Set it up to run regularly (right now I'm running the script instead of setting it up as a Cron job)

- Documentation / Build Guide.
- - Next step: Use the backup Canon Lide 20 to assemble the physical build guide
- - Next step: Review notes on existing process and create:
- - - Simple Pi guide (Just to view images as you like from the scanner)
- - - Timelapse Pi Guide (Include automation for creating timelapse video)

Beyond the above, there are two variations on this project that I would like to pursue:
1) Building a cylindrical scanner. Scrap the frame/body of an existing scanner, mount it to a glass cylinder and have it scan 360 degrees. I think it would be easier (physical constraints) to get it to scan from the outside in, but I think it might be more interesting to get it to scan from the inside out (buried in the ground). Similar to existing Mini-Rhizitrons, but with a 360 degree view.

2) Building a webcam version. Similar to existing Mini Rhizotrons, but significantly cheaper. This is how this project originally started. The image quality and viewing area will be reduced, but we'll have a significantly higher frame rate and nearly real time (ms delay) viewing. Taking an image once a day seems fine for tracking root growth, but tracking the path of certain bugs below ground seems like a 1 frame / minute frequency.

It would be wonderful to include additional data for both build options, ie:
 - Moisture
 - Humidity
 - Temperature