-
thoughts on the sensor
05/28/2014 at 18:17 • 0 commentsThese are the two ways I'm trying to choose one of. The sketches should help understanding how the sensor is going to work.
The sensor will rely on the red-eye effect: the light of a LED will form an image on the retina. The backscattering from retina will "send" the image of the LED back into the actual LED. One can sense that either by placing a photodiode really really close to the LED (on config.1), or using a semitransparent mirror to split the beams (on config.2). The light reaching photodiode will be at maximum when the image of LED/photodiode is exactly on the retina, i.e. is precisely in focus.
-
the microscope
05/28/2014 at 12:47 • 0 commentsI have uploaded the picture of the microscope to be hacked.
I have found out that there is an image plane inside the eyepiece of the microscope, surrounded by a nice aperture that defines the FOV. That's a good place to put a sensor, but:
* it will obscure the view through the microscope, so it has to be placed near an edge of the aperture. I'm not sure if it will work too well, I'd prefer placing it in the center.
* it's tight there.
Another option is to put a semitransparent mirror inside the tube the eyepiece is mounted to, drill a big hole in the tube and place the sensor perpendicularly. So, I'll have unlimited space there, but there are drawbacks as well.
* semitransparent mirror will lower the light transmission of the microscope
* two low-R reflections will be added into sensor's optical path, it WILL get problematic.
That's the main thing I'm thinking on now.
-
Started!
05/28/2014 at 11:53 • 0 commentsThe idea has been cooking in my mind for quite a while, and I actually wanted to use it for another design contest (TI's ADC). But the hackaday contest is so much cooler, so I decided to have a go at it, despite it may not be very "connected".
The progress so far is a good idea on how the eye focus sensor can actually be made. So, the project is in the planning stage - nothing has been built yet.
The sensor would rely on the red-eye effect (aka cat's eye), which is the strongest when a light source and a sensor are both in focus on the same spot of the retina.