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Basic DIY camera for educational use

Started Apr 8, 2019 | Discussions thread
ProfHankD
ProfHankD Veteran Member • Posts: 9,147
Re: shed the sensor !!

Bernard Delley wrote:

the sensor, whatever kind, is always a complex electronic blackbox. I think for an educational project in the image sensing electronics you would have to start at the photodiode. Of course the photodiode and the nano- amperemeter (or better high impedance DC voltmeter) risk to remain blackboxes. An LED is also a photodiode of course. You could even try a 'crystal detector' as a more hands on diode. But, to bring the light detection out of the black box seems to require basics of quantum mechanics and Shockley's thermodynamic device equations. So that remains way too much for most pupils unfortunately.

So perhaps do away with the sensor. No electronics at all ! Use a white screen. You may start with a camera obscura . You could include prisms, gratings and spectra in your optics course.

The LED is well within reach (using the charge timing circuit I pointed to). In fact, way back when I was taking my AP Physics class in 1976, I built a circuit using a LED to receive data sent by modulating a laser.

The catch is, you'd probably be talking about really low resolution -- just a few pixels.

Could do just one LED and scan... X/Y motion control is really cheap and easy now using servos, so you could get perhaps 100x100 pixels scanning one LED. (It's cheap and easy to scan using steppers too, but the controllers get more black box-ish.)

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