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Re: Create a mask with UV sensor
Posted: Tue Aug 11, 2015 6:41 pm
by jon_bondy
Regarding the Mask PNG, how do you determine the brightest and darkest value? That is, must one point (somewhere) be white and another point (somewhere be black)? Or is the darkest value 50% gray?
Re: Create a mask with UV sensor
Posted: Tue Aug 11, 2015 7:41 pm
by nc42
The white to black is a function of the showzbuffer command in rhino which makes white the surface closest to the camera and black the furthest away. So on the case of my example it's a function of the uv reading surface and the plane. After that it's a matter of trial and error too adjust it so you get something resembling even exposure over the whole protection.
Re: Create a mask with UV sensor
Posted: Tue Aug 11, 2015 9:43 pm
by jon_bondy
Suppose one put a sheet of white paper where the VAT should be and photographed a fully white projected image from above. Assuming that the brightest areas in UV will also be the brightest areas in other "colors" (which I suppose translates to supposing that the lens system does not treat UV significantly different than the other "colors"), couldn't one generate the PNG more or less directly from the photograph? What am I missing?
Re: Create a mask with UV sensor
Posted: Wed Aug 12, 2015 3:04 am
by sodium
Re: Create a mask with UV sensor
Posted: Wed Aug 12, 2015 4:25 am
by nc42
Re: Create a mask with UV sensor
Posted: Mon Aug 17, 2015 7:19 pm
by sodium
Re: Create a mask with UV sensor
Posted: Mon Aug 17, 2015 7:54 pm
by nc42
Not an arduino master and haven't use the while command before but I think this should do it...
https://codebender.cc/sketch:142435It should show the reading until you press the "R" button again. I repeat should...
Re: Create a mask with UV sensor
Posted: Tue Aug 18, 2015 3:32 am
by sodium
Re: Create a mask with UV sensor
Posted: Fri Aug 21, 2015 11:40 pm
by cardin1
I just implemented this using a BH1750(. You can find it a lot cheaper on Ebay. The only reason I used this sensor is because I had it readily available in my neck of the woods. I didn't write any of the attached code, it was just a copy and paste of Nate's(big thank you) code and Claws' library(. Since the BH1750 outputs digital lux readings, the code is a lot simpler. Having said that I would have used the UV sensor if I had it available, I suspect the results would be very similar and it would have saved me some cut and paste
.
If you want to go this route, download the file and also add Claw's BH1750 library. After you load it in your arduino, the procedure is exactly the same as the one described by Nate.
Re: Create a mask with UV sensor
Posted: Sun Nov 29, 2015 3:38 pm
by Mariraja
Hi guys,
I am new to SLA. I couldn't grasp the idea and functionality of using a mask with UV sensor. Could some one kindly give me idea on what it is? Thanks in advance.
Regards,
Bimmer