There’s a new plug in the works, with a really neat TSL2561 light sensor:
The chip is even smaller than what I’ve been working with until now. The nice thing about the TSL2561 is that it has six orders of magnitude dynamic range and that it’s interfaced via I2C.
The JeePlug port headers are in fact perfect for sensor chips like these, which often only tolerate up to 3.6V:
The Lux Plug will also work with an Arduino, through the Plug Shield.
Stay tuned. There’s more coming…
Is there special reasoning behind choosing the TSL2561? Did you check the ISL29003 for comparison? To me the ISL29003 looks better because of the 4 selectable Lux-ranges and the easier calculation of Lux from the output.
I admit I didn’t look at the ISL29003. Is it a big deal? The range and results are comparable, the Taos chip is slightly cheaper. The software should not be an issue once wrapped into a lib, it’s still very simple code. My impression is that the 2-diode approach with the TSL2561’s additional IR sensor might produce “better” results, but I don’t have any facts to back that up.
Both chips use 2 diodes with different spectral sensibility.
Could you find out what the max Lux value for the Taos chip is? I didn’t see it in the datasheet. I remember that some guys working on onewire weather stations had problems with the max Lux range and changed diodes several times to be able to measure direct sunshine in summer.
But I guess even the 64KLux mode of the ISL isn’t enough for that.
Same – 65535 Lux as max, AFAICT. According to http://en.wikipedia.org/wiki/Lux, sunlight seems to go up to twice that – I’d use a 1-stop gray filter from a camera to get that extra range if it is important.
Good idea with the gray-filter. Much easier than trying to calibrate anything self-built going up that range… Thanks.