8 years ago i installed a one wire illumination sensor that is checking the sunlight to determine if a pool boiler should turn on (if dark skies) or not(heated by solar thermal array). its worked great for all this time, and my values were usually 700 to maybe 225. those values are hardcoded into my arduino. today, during the day it varied between 24 and 88. I checked the enclosure of the sensor and found it ok, not covered and not dirty. do these sensors slowly die? does anyone know a source for these? i can’t seem to find one on the internet. thanks
Which sensor? is it one of these?
UV over time might degrade them, if it’s an analog sensor you might have corrosion or a lose connection somewhere adding resistance.
no its not a board. it looks like a dallas temp sensor, standing on its two legs that are soldered to wire going to the arduino. i cannot find where i got it. re degradation, its strange that it would happen overnight
ok i at least found a source:
i am still wondering why it would suddenly change output
OK, photocell. Those could absorb moisture but shouldn’t suddenly change resistance, I’ve seen some in service for decades that still work. These are the same sensors that turn streetlights on at night or nightlights on when it gets dark.
They’re super cheap, you might just replace it?