Two undergraduate students spent about 7 weeks (15 hours total) working on this project during class time. We built the low-cost microscope and had the printed parts pre-printed (we did not 3D print any parts ourselves). Here are the results of our work, including problems, solutions, and takeaways.
The physical build of the microscope was pretty straight forward, and fun to complete. We did come across a few issues. Listed below are these issues and the steps we took:
- Assemble the actuators, Step 3: We were not able to figure out which side of the washers were the curved sides and the flat sides, so we just placed the washers in no particular orientation. This did not affect the build at all.
- Assemble the basic optics module, Step 2: We were not able to remove the lens off of the camera because the lens was seated too low to grip with the tool provided. We ended up using pliers to twist the lens out, but this damaged the camera. We had to replace the camera module entirely, and the second camera we used had a higher seated lens, so we were able to remove the lens without any problem. It seemed like we just had a defective camera module.
The most problems we encountered were with getting the microscope to work and getting the Raspberry Pi software to show up on the monitor. When everything was hooked up properly, nothing appeared on the screen (no HDMI was detected). Here are the steps we took, and their results:
- Replaced the raspberry pi board → had no effect
- Reflashed the SD card → worked
- Utilized the terminal once the software popped up → worked really well. We checked to make sure the camera was detected and enabled on its own. Once that worked, we then rewrote some of the code to make sure the input was directed to the HDMI cable. We also often rebooted the system from the terminal and that worked sometimes as well.
Once the Raspberry Pi software appeared on the monitor, we began encountering problems with the Open Flexure Software and the camera. We kept getting a “Camera disconnected” message. Here are the steps we took and their results:
- Replaced the flex cable → worked for a little, then stopped working. This cable is really finicky and needs to be replaced often due to its fragility.
- Replaced the Raspberry pi camera module → we ended up replacing this 3 times, and each time we replaced it, it worked for about 24 hours, then stopped working.
In the event we finally got the camera working, we encountered additional problems:
- The image shown was really washed out and very white, and when we used the auto-color calibration feature, it made it worse. We were unable to solve this problem.
- The image showed black and white stripes and a pink hue no matter what image was on the slide. This was solved a little when we replaced the camera, but the pink discoloration still remained.
We learned a lot while building this microscope. Here are our biggest takeaways:
- Be patient. A few of these steps take patience and can be done incorrectly if rushed.
- Be persistent. Don’t give up when things don’t work! Try replacing different components if possible. Try rebooting or replugging some cables in. Sometimes that’s all it needs.
We want to thank Joanne Long and Will Dickson for their support of our work, and their generosity in providing feedback and helping us troubleshoot. We also want to acknowledge a previous forum post, Extending OpenFlexure to Schools, and mention that the IO Rodeo kit and accompanying instructions significantly facilitated the assembly process. Finally, here is a full Build Report with supplemental comments and pictures to accompany the original build instructions. Thank you, and we hope this is useful for future builders!
