Hi everyone-- I’m figuring out what to print and I have a dumb question.
Can I print the reflection version of everything and still get a microscope that works with transmission? To me it looks like it would work, but I want to make sure I’m not missing something…
(Biggest issue that I see is that the power for the illumination LED isn’t gated in any way, so at the very least one needs a switch to pick which LED should be lit).
Having the reflection optics in the optics module will increase the noise when used in transmission as a lot of the light trap is removed and there are beam splitters and other optical components there instead. For a hobby microscope it should be fine.
You could use the pi GPIO pins for LED switching. I am not sure I would drive LEDs directly off the GPIO pins, but you could get some little relays.
Cool, thank you! Yes, I know that light may leak / scatter and that I’m giving up about half the signal. I’m hoping that that isn’t too bad for a bit better than a “hobby” microscope, but in any case it’s good to hear that it’s not a complete dealbreaker.
Pi GPIO pins are 16 mA source/sink, so that’s not going to be great for illumination, but I’ll figure something out-- probably just a mechanical switch to keep things simple.
Thanks again!
A mechanical switch seems the way to go. If you did want to go the relay route you can cheap little relay boards quite easily now (example from an evil company, less evil companies sell them too!).
If I were to do it, I’d use something like this MOSFET board. Does the software have any support for controlling GPIO extensions? (If not, the plugins dynamic UI stuff looks rather unexpectedly nice).
It’s going to be quite some time until I have a microscope-- I’m waiting for most of the stuff from Aliexpres.
Nothing built in already as far as I know. But as the extensions run on the server and are in python it should be easy enough to do and to make the UI for it.
To avoid the expense of a second tube lens, I was hoping to use the same optics unit for transmitted or reflection illumination. I have found that by inserting just one wall of the cube it closes off the side of the unit. I have also thought of covering the opening with black tape until I need it. Will this cause added reflection or light noise?
@mlyle wondering if you’ve managed to make it work?
Very late to this conversation, but would the new upright build of the v7 version be easier to modify in order to accomplish both functions? If so, this could be a game changer for educational facilities, where buying multiple devices might not be feasible.
The optics module is more accessible in the upright version if you wanted to change it.
It should be possible to do both without changing the optics module, just switching the LED used. I think someone has reported doing that somewhere on the Forum. The Sangaboard v0.5 ways of controlling more than one LED, although not controlled by the OpenFlexure software.
We should have a dummy beam splitter module that is just a light trap. I tried coming up with some one a while ago but it’s not really done yet. The beam splitter being held in place by self tapping screws also does not make this an attractive option.
I have seen some community work on a TPU friction fit beam splitter. However this creates plastic shavings that drop onto the sensor. I feel magnetic attachment is going to be ideal.