I have a project where I'm using a TAOS TSL251R[1] pointing at a CRT, and I want a TTL out when the area under the photodiode is "white", and turn off when it is "black". Now the issue is that CRT phosphers decay in light intensity quickly, so the output looks like the following (imagine it smoothed with a gaussian, a 100Hz refresh means the time between the light pulse peaks is 10ms):
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----- ----- -----
----- ----- | | | | | | ----- -----
| | | | | |-----| |-----| |-----| | | |
-| |-----| |-----| |------| |
>BLACK >WHITE >BLACK
Any other smarter ways to handle this? Thanks for any help in advance!
Ian
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[1] http://www.taosinc.com/ProductDetails.aspx?id=61