Help with sensor color

Discussion in 'The Projects Forum' started by impilar, Apr 14, 2010.

  1. impilar

    Thread Starter New Member

    Apr 12, 2010
    Hello, I'm starting to use the sensor TCS3200 that is a small improvement of TCS230, and I had the same problems as other user post it, I have read several of your posts on this and other forums. But I don't found some solution.

    I found several examples taos web pages and parallax, even with white calibration , but have not yet achieved the reader to read properly. For example, to read the value 255,255,0 I obtain 238, 183, 81, to read 255,0,0 I obtain 120, 33, 37.

    The colors are printed on paper, but I get similar responses from an LCD screen. What I can do?

  2. rjenkins

    AAC Fanatic!

    Nov 6, 2005
    I've not seen these before, it's an interesting device!

    Looking at the datasheet, the white channel can be anything from around 12 to 18KHz at the reference level they use, then the full response of each colour channel has quite a spread from that in turn; around 60-85% or 85-105% depending on colour

    I think you need to calibrate the white output at maximum illumination (by adjusting the count capture time), then once you have that set you can calibrate the maximum of the RGB outputs individually.

    Looking again at the frequency ranges, the reference level frequencies are a fraction of the saturation level, eg. reference levels are around 40-50uW, saturation is around 1300-1800uW so outputs may be waay higher that the reference frequencies.

    I think you need to use 16 bit capture to get a sensible output from this device, with enough accuracy to properly scale and calibrate it.

    Datasheet, for info: