Hi all, a newbie here, I yet have very little experience with raspberry pi and electronics in general.
Context: I REALLY want to get openflexure to work in order to take images of soil samples. I have been assembling the high resolution version following the instructions to the “T”. I am so grateful that this project exists, the design is genius and the instructions are near perfect, at least for the recommended build with Sangaboard (but I am wondering if the authors are open for comments for where things where not easy or clear for me).
Problem: Ok, i have r-pi 4B, camera v2, Sangaboard - all connected. The Raspbian OpenFlexure OS image installed, when I ping r-pi from my terminal I get the ping. When I open OpenFlexure Connect I can see the microscope and the ominous message “Camera Disconnected”. From the ssh terminal to the rpi I get the following:
$ vcgencmd get_camera
supported=1 detected=0
Doesn’t look good, right? But I am sure I connected the camera the right way and the belt is not damaged. I will try to change it to a spare one now, but otherwise really not sure what could be wrong. I found an older thread on the forum that was resolved but updating and upgrading didn’t help, plus my image on the SD card is very fresh.
Another thing I find strange is that the illumination PCB is not turning on - should it turn on automatically?
Otherwise I can control the motors manually, so that part seems to work…
The illumination should turn on, I would pull out the electronics drawer. It is worth checking the ribbon cable is the correct way round, and that the illumination is wired the correct way round. Also worth taking a photo of where the ribbon cable enters the camera.
I am wondering now if I bought a wrong camera cable >.< The two that arrived look like this, i used the narrow part for the board and the straight part for the camera.
I have just had a look back at the currently released instructions (v7.0.0-beta3). If you went through the web site that release is what you will have seen.
We have a number of improvements in the works, particularly for the wiring instructions. You can see the current working copy at Assembly Instructions . There is the usual warning that as a development copy they may change at any time and may be broken.
One of the changes is the render of the wires for the LED PCB in the illumination. The colours were the wrong way round, which has confused others.
The working copy looks great, I already see a couple of things I wanted to suggest, hehe Like preparing the SD card for rpi before finishing the electronics drawer However, the LED PCB rendering looks the same to me? (in my mind I called it “plus is red and is closer to the edge”). But yes, it is not lighting up…
Any further suggestions for the instructions would be very welcome.
In the illumination, I was meaning where the wire plugs into the small PCB with the LED on, in the illumination module itself. The renders in the v7.0.0-beta3 instructions have red to -. The words are correct in both. The corrected render is
Aha! I have indeed wired it the wrong way around on the top, but now I fixed it and the PCB works, hurray! Thank you so much for the explanation. Now just to wait for the camera connector.
When will the current working copy become the default one, displayed on the site? Perhaps I could then go through it and leave comments if necessary, while my mind is still fresh (I already want to build a second one, this is addictive).
When we do the RC release we will do a “feature freeze” so we will be in “bug fix only” mode until we finally release v7 (otherwise we will never get v7 out the door!).
I think fixing a bad/confusing phrasing would probably be a bug fix, reordering instructions making new renders probably wait for the next release.
As for time until we move to RC and then release… soon! But we have been saying soon for a while!
I completely agree with having a step in the instructions to burn the image to the SD card if it hasn’t been done already. IO Rodeo in the US (OpenFlexure Microscope Kit – IO Rodeo) does offer an SD card with the Raspberry Pi image already burned on to it, but a preburned SD card is not always the case.
Buy from trusted sources. I burned 3 raspberry pi cameras by using defective ribbon cables. it was a very costly mistake. @JohemianKnapsody can talk more about it.
Thank you @dgrosen, let’s see what kind of cable I get, it should arrive in a couple of days. It’s been a bit of a challenge to find the 15-15 pin one, and specifically a 20cm in length. I am actually getting a 30cm cable. My microscope objective might also be too long, I’ve ordered a back up too.
@WilliamW The working copy of the instructions is great! But I will have a couple of suggestions, they are of course up for debate.
The instructions are correct when they say that the “Attach the viton bands and foot” is the trickiest step in the whole process. I broke my main stand twice at that step. So, I suggest moving the whole section up, right after the all the parts have been printed. If the main stand gets broken then there is less unscrewing to follow
The reason I broke the main stand twice is not only due to my inexperience and clumsy hands, it might have also been the choice of the filament. According to my more 3d-printy friends, white filament is bad for the nozzle and makes for more fragile parts. For my 2nd OFM I am going black as night.
I wish there was more clarity on the camera ribbon cable. While “This is a 15 pin FPC cable with 1mm pitch.” is a very useful detail, I still ended up buying a cable that was suitable for r-pi 5 only. Perhaps a picture with a warning would be helpful.
I am wondering if the physical measurements of the microscope objective are helpful? I see in other threads that people sometimes buy objectives that are too long.
Otherwise, the instructions are amazing, I am a complete newbie in electronics, this is my first project working with raspberry-pi, stepper motors, etc, and so many things worked out of the box! Thank you so much for OFM!
I’m curious if I did get a wrong objective. See how it pokes above the stage? I mounted it as low as possible. Will the z actuator bring it down? (the image is rotated so that the objective specifications would be read more easily). Also, while I am waiting for the camera ribbon cable, I am playing with the motors a bit… is there a way to bring them back to centre? Asking for a friend…
Thank you for the suggestions on the instructions. We already have an issue on making the camera cable clearer, but we should think about the Pi 5 cables as well now that they are a further confusion.
The objective looks fine, as long as it gas got there by the z-actuator motion. The working distance for a ×40 lens is much less than 1mm, so you need to have the slide with the sample on the underside and the lens almost touching the coverslip. Try moving the z-axis to lower the lens to get it just a little below the stage
Like preparing the SD card for rpi before finishing the electronics drawer 
However, the LED PCB rendering looks the same to me? (in my mind I called it “plus is red and is closer to the edge”). But yes, it is not lighting up…
