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OPT3001: Howto measure ambient light side-by-side a bright LED?

Part Number: OPT3001
Other Parts Discussed in Thread: OPT3004

I need to measure room/outdoor light to control the brighness of a fairly large ~0.5W LED.

Are there any smart solutions to this? 

i.e. something that can sync and only measure when the PWM to the LED is off.
(I'm not able to turn off my lead to measure since the ambient sensors purpose is to adjust the visible led to match the environment)

any tips would be great!

  • Hi,

    OPT3001 or OPT3004 the integration time can be set at 100ms or 800ms. You can check the PWM of the LED, but likely one or both of these settings will be much longer than the LED on/off time device will report brightness level similar to what the human eye will perceive. Side-by-side you will also need to consider angular characteristics of LED assuming you actually care about the LED light emitted out the front. A partially reflective plate or integrating sphere could also help with that depending on accuracy needed. Also you will want to consider that the LED does not saturate the OPT sensor. This can be achieved by positioning or also attenuation (half mirror, etc).

    Best,

    Alex