Hi all,
The TSL2561 is nearly the light sensor I am looking for: I2C output, wide range of sensitivity, calibrated, useable for the visual spectrum and available on a breakout board. The "counts" can be calculated to give Lux readings, the datasheet contains the formula.
a) Is there a formula to transform the "counts" into µW/cm2? Or
b) Is there a sensor which outputs µW/m2 or similar directly? Or
c) Can I calculate µW/cm2 from the Lux value? Since I don't have monochromatic light of 555 nm, but (varying) daylight, this is not trivial.
Thanks for sharing your ideas!

-richard

 

Photometers register light intensity after being weighted by filters corresponding to the three “color channels” in the human visual system. If you knew the exact spectral distribution of the light you might be able to work backwards but that takes a spectrometer, which the Taos device cannot simulate. In other words you probably do not have the correct detector.

 

Not recommended for new designs. Please see TSL2572x device family.

I am looking at the TSL25722.

" TCS34715 " the data sheet is a good read. "color"