Having problems with erratic readings from sensor

totally forgot i have a multimeter so checked the voltage going to the sensor its 3.33v occasionally dropping to 3.32v so all looks good there, checked the connectivity between the two points on the data cable and all appears to be good there, but just to be sure i swapped the cable out for a new one. no change, i’m starting to think maybe its the sensor…

Yeah at this point that is my thought as well. Perhaps the sensor got fried when it was hooked up to the 3.3V pin? If the photo transistor was fried then you would have no voltage across the resistor in the other half of the voltage divider hence the pin 32 would be just floating giving you the results you’re seeing.

checked the voltage across the the transistor and it matches what was on the logs, fluctuating between 0v, 0.04v, 1.2v, 0.12v, 0.07v … but at the same time the log readout shows everything is 0v untill i remove the probes. if I unplug the data cable then the readout remains the same.

edit: if I check the voltage across gound and data ( my thinking is that this is what is being converted back into the lux range) i get a constant 0.01v

just gave up and bought a new sensor, (postage was more then the sensor was lol) after I pressed ‘pay now’ i rechecked the sensor and it’s started to settle… it now only fluctuates by about 1 or 2 which i guess could be down to the fact that light flicker , we just dont normally see it.

Yeah I was going to say you could try reading the sensor directly and if that seemed right then perhaps pin 32 is bad.

1 Like