[Product Revision] Color Sensor (U009) - Ability to turn off LEDs
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It would be nice if there was a revision of the color sensor that allows the LEDs to be turned off/on (via I2C). So it can be used for measuring a light source's color spectrum (leds off) as well as an object's color (leds on).
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According to the schematic the LEDs are hard connected between VCC and GND (with a 1k Resistor in serie). It may be an option to misuse the sensors INT pin and its limit threshold settings to switch the LEDs on and off. It is a open-drain with a max of 20mA. Or spend an extra I2C output driver (one Output for white LED or more if you want different LED colors - deep blue or ultra violet may be helpful to identify e.g. fluorescence).
Anyway, it will never be a spectrometer like device as there are only 3 colored sensors with a more or less wide spectral bandwith but still gaps between. -
Using the INT is a good idea (I was thinking an extra IC), but now that you mention it, having both white & UV could be useful to others as well.
I shouldn't have put the word "spectrum", but rather (color) "temperature" (what I'm using the sensor for, roughly calculated from the RGB intensities). To truly read a spectral response would require a prism/grating and a linear monochromatic sensor (and calibration).