Add a DECTRIS SIMPLON API camera interface

[Baharis]

Context

I received a request to implement a DECTRIS SIMPLON API in Instamatic for a future user interested in using Instamatic with a JEOL + DECTRIS setup. I contacted another group who already got a similar setup working, but unfortunately due to unexpected circumstances I could not base my implementation on theirs. Consequently, I sat down today with the SIMPLON 1.8 API documentation and wrote the interface to the best of my abilities.

I called the new interface simplon after the API it communicates with. It is designed to work with any camera that uses this API, including DECTRIS QUADRO and SINGLA. It uses requests library, which has already been an implicit dependency of Instamatic via package virtualbox. Otherwise, the implementation it is similar to that of ASI-dedicated serval.

I already tested connection and some functionality against ansto-simplon-api. However, for simplicity, I decided to read images from the slower monitor rather than a file stream, and said module is not implemented in their (otherwise great) tool. Consequently, I will test the new code on the live detector next week and merge the code after it is confirmed to work.

Code additions

• camera_simplon.py: Implementation for DECTRIS detectors via the SIMPLON API;
• simplon.yaml: Configuration file with default values set for DECTRIS QUADRO;
• camera.py: Added 'simplon' as one of available camera options;
• pyproject.toml, requirements.txt: Added explicit requests >= 2.0.0 dependency;
• readme.md: Added support for "DECTRIS cameras through SIMPLON API".

[Baharis]

Post testing

After troubleshooting, the camera communicates with instamatic as expected. Still- and precession-based experiments work fine, get_movie was not tested extensively albeit the camera is written in such a way that get_image is essentially a get_movie(n_frames=1), so I do not expect issues. The monitor interface should work fine at rates of 10 or below FPS.

For anyone using camera, if you ever have any issues with the implementation or look into increasing image rates, please suggest an update to this implementation utilizing streaming mechanism, or ask me to prepare one.