Today a small camera board made by Sanm arrived in the mail from Hong Kong. It came without a USB cable, just a 5-pin header, so I used the pinout diagram on its product page and wikipedia's USB pinout reference to put together a cable.
Sanm pinout: 1 VDD 2 D- 3 D+ 4 GND
Then I took out the filter by unscrewing the lens and prying it loose, closed it up, and plugged it in, and it worked. It identified itself to my computer as a "BisonCam NB Pro" which appears to be the internal webcam of the MSI GT780R.
The camera has a sensor half the size of the Syba webcams that currently come with the desktop spectrometry kit, and the board is much thinner 60mm long:
The board has a bright white LED on it that needs to be covered. I put some electrical tape over it:
I mounted a DVD fragment using two layers of double-sided foam tape:
In order to get a flat surface for mounting, I used the broken off mounting point of a Syba cam, and stuck the Sanm board to the side of it with double sided tape. In this photo I marked where the body of the Syba cam had been with a pen, and ticked off the lens location, for comparison. I believe my lens placement for the Sanm camera is roughly the same place as the Syba cam:
The Sanm cam barely fits. It sticks beyond the lip of the conduit box, but the lid bulges out a little bit and closes fine:
the results are a little dim, despite the otherwise great quality of the camera. Any thoughts?
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wow, looks spectacular. Can you post a full frame grab instead of a spectrum? Maybe the brightest point is not on the sampling line.
Also, just to think about brightness, could you post a comparison with a syba-based spectrum from the same distance and setup?
Sometimes it helps to diffuse the incoming light by putting a napkin over the bulb, so you don't have to align it as well with the device. If this is an alignment issue, that'd solve this, but if it really is about the sensitivity of the camera, maybe we have to come up with another solution.
Very exciting! Keep us up to date about the USB cable too!
This board could easily be used with a raspberry pi as well, and would be so much thinner and more compact!
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That's a really good spectrum, even though it looks a little dim. There are no overexposed peaks in any channel, but if the image had been brighter, some peaks would have been lost in the brightest channels. So the exposure is really as good as you can get.
A greater limitation of the hardware may be the resolution. There is not even one pixel per nm, so there is not much resolution to spare to define where the peaks are.
It's cool to see such good results from bare ingredients.
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