TSC230 color sensor as a spectrophotometer

Tom PTom P Posts: 97
edited February 2008 in BASIC Stamp Vote Up0Vote Down
I have been looking over the TSC230 color sensor and have a question.
Does any one know if the sensor can be used as a spectrophotometer without using the supplied white LEDs.
Can I use the sensor to measure sunlight spectral output at different wavelengths?

Post Edited By Moderator (Chris Savage (Parallax)) : 2/28/2008 9:42:55 PM GMT


  • 4 Comments sorted by Date Added Votes
  • allanlane5allanlane5 Posts: 3,815
    edited February 2008 Vote Up0Vote Down
    I'm pretty sure you can't.
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 19,721
    edited February 2008 Vote Up0Vote Down
    You don't need the LEDs and can switch them off if you're looking at an emissive source. For sunlight, you should cover the lens with both a diffuser and a dark neutral density filter. The former will ensure that the radiation doesn't get focused on a small group of pixels (possibly burning them); the latter keeps the sensor from saturating. You need to keep the lens in place, since it includes the necessary IR filter, unless you want to add an IR filter separately, in place of the lens and diffuser.

    Bear in mind, though, that this is just an RGB sensor, not a multispectral (beyond three bands) spectrophotometer. You can view the spectral photoresponse curves in the TCS230-DB docs or get the specs from the TAOS datasheet.

    “Impossible is just a big word thrown around by small men who find it easier to live in the world they'’ve been given than to explore the power they have to change it. Impossible is not a fact. It’'s an opinion. Impossible is not a declaration. It'’s a dare. Impossible is potential. Impossible is temporary. Impossible is nothing.” –Muhammad Ali
  • Adrian SchneiderAdrian Schneider Posts: 92
    edited February 2008 Vote Up0Vote Down
    I fact I have done something similar -- laser fluorescence colorimeter -- with mixed results. There are only
    three color filters (plus blank) with a wide pass-band. You may need more and narrower filters to obtain
    useful data. Sensitivity seems not to be a problem with your application. However, I would give it a try, it is
    an interesting experiment anyway.
    I recommend removing the color filter which adapts the sensors wavelength response to human vision. Use
    the wavelength response curves that come with the sensor to calibrate your data.
    Depending on your result you may consider using multiple sensors and supply your own filters (eg. www.optosigma.com).

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