November, so soon! I kind of had to put this one down for awhile and work on things that were not laptop-centric, I just was spending too much time in front of a computer screen. Luckily, Tiuri De Jong was on the case, and he has developed the proof-of-concept code I posted earlier into a fully-working demonstration.
I uploaded it to my Arduino, and I’m getting stable results with an apparently linear response, although the specific numerical values themselves aren’t particularly meaningful. For example, under my workbench lamp that I metered at about 40fc and has a CCT of 5000K, it measured 290fc at 3500K. I get that the part would require calibration before it would be useful, but it’s strange to me that it would be off by 1500K color temperature and a factor of 5 for illuminance, out of the box? I’d be interested to know if anyone else has a similar experience.
What I’m working on now is measuring the values given by the TCS3414 vs. a known accurate illuminance and color temperature meter, to tell if the deviation from true value is a constant, or a linear function, or what. I’ve verified that the calculations are done correctly in the code per the datasheet.
But in the meantime, it seems like a shame to deprive everyone else of Tiuri De Jong’s complete and, might I add, lucidly written code, so it may be downloaded here:
I’ve also posted the code in full after the jump.