Here is a paper from 2014 on making one computational microscope using a raspberry pi w/ pi camera and a 3d printer: https://pmc.ncbi.nlm.nih.gov/articles/PMC4169052/

It has a resolution of around 600 nm but also provides per-pixel angular photon phase. It’s only about as big as a raspberry pi.

The FPM approach makes it easy to correct for lens problems, alignment problems, manufacturing errors etc, because of how simple the iterative process for fitting the model of the object is.

Oops that’s a different paper