This is great, and I even bought a couple so I can include this hardware in my Raspberry Pi work I've been doing. I don't have any comments on the code as of yet... I'll report back here after the units arrive and I've had time to read the datasheet and do some testing.
If you do a fair amount of work on stuff like this, you may be interested in checking out some of my mentioned RPi stuff in my CPAN home page (the RPi::* and WiringPi::API may be the ones of interest).
I do have proper light meters as the purpose for my RPi work started off as a project to automate indoor grow rooms, but this hardware will fit in nicely (I admit I was having so much fun writing this code, that I would randomly just buy different ICs just to get familiar with programming them). There are apps out there for smartphones that are reasonably accurate (at least accurate enough to tell whether your numbers are within a reasonable range). You may want to take a look at some of them.
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