Adafruit has an ALS-PT19 Analog Light Sensor Breakout. It looks like it has a 10K resistor on it:
The ALS-PT19 datasheet says that resistor is to convert the output current of the transistor to voltage. Why would Adafruit have selected a 10K resistor?
Given a 5V power supply, I would assume the breakout would max out at about .5mA. Is that right?
Based on this graph, it looks like it'll max out at about 4K Lux, right?
If an overcast day is 1000 Lux and daylight is 10K Lux, was the decision to maintain precision at lower levels of the scale and let it saturate at anything higher than "almost daylight?"
Let's say I wanted to also have accuracy toward the really bright incandescent range where the output is as high as 5mA. If I wanted to do that, would I put a 1K resistor there instead?
If I wanted accuracy at both ends is there a way to include both the 10K resistor output and the 1K resistor output from the same phototransistor or would you put 2 phototransistors on the board for that?