Aurora Camera
Since moving to Orkney we started to see the northern lights frequently - I thought it would be a good idea to make a live ‘webcam’ to monitor the aurora. So I re-purposed an in-development all-sly camera to be an aurora-cam.
aurora-cam
So there is nothing really new here - a number of people have done pretty much the same sort of thing. My all-sky camera had the ’new’ Raspberry PI Hi Quality camera with a fish-eye lens, but I just replaced this with a 6mm Cosmicar/Pentax CCTV lens.
Basic shopping list:
- Raspberry Pi Model 3B (with Wifi)
- Raspberry PI High Quality camera
- Micro-SD card, I had a 64GB one to hand - I later upgraded to 256GB as kept on running out of disk space.
- 12V to 5V ‘buck’ (these are deveices for cars to provied step down power to a USB outlet)
- 12V power supply (had one from an old laptop)
- Lens - 6mm Cosmicar/Pentax CS lens from a previous project.
- Waterproof box
Although there are a few projects available on GitHub and other sites, I have at the moment decided to program it all myself using Pyhton. First some very simple code to just take photos out of the window and display using a web front end (using Flask). I’m using raspistill to take 20s exposures, then imagemagick convert to resize, set colour balance, set levels and gamma, and title each frame with date/time. At the end of the night ffmpeg is used to make a video of the whole nights activity. If a video is worth sharing, I download and trim and rescale to something like 480p using Quicktime.
A few gotchas to document.
- Using Flask I was getting out of memory errors when trying to take images. Increasing GPU memory made no difference. This was solved by disabling the Flask debug mode.
- There was quite a bit of fiddling with colour balance and levels/gamma to get a nice rendition. Current settings are reasonably pleasing.
To Do’s
- Live stream to the internet - I have a few ideas on how to do this, but not settled on a plan. I need to talk to my internet supplier…
- Would be nice to be able to browse the photos via the web interface.