DIY Picroscope

With the great low cost and rapid acceptance of the Raspberry Pi, one interesting project is its use for amateur microscopy.


The device is a Raspberry Pi Model B (512Mb RAM) with an 8Gb Class 6 SD card running Raspbian Wheezy. An open source project exists to easily monitor an attached Raspberry Pi Camera Module, called Picroscopy. To properly focus the module in an afocal setup on my Amscope monocular microscope, I needed to use a set of tweezers to unscrew the module's lens (there is some glue there, but applying some pressure eventually caused it to twist). I had to unscrew about halfway in order to get proper focus, using a 3D printed camera mount adapter, found here.

I modified the software to boot at startup automatically, and used a small shell script to capture an image every few hours. A simple indoor/outdoor outlet timer turns on the microscope lamp for the relevant interval. The next upgrade will use the Raspberry Pi's I/O pins to drive a relay that turns the lamp on only for the short time needed to properly image, since the timer runs on half hour intervals.

Another potential pitfall is the thermal drift of the setup. I don't yet have a great temperature control solution, but a longer ribbon cable than provided for the camera module lets me put the dust cover over the microscope during operation, which does help maintain a steady temperature and therefore fixed focus for longer image runs.


Microscope Setup