Troubleshooting ADC Readings from Photodiode on Arduino
Hi everyone,
I am trying to rebuild a device and have wired everything according to the schematic:
You can see that the output pin of the photodiode (pin 5) is connected to the ADC pin A0 of the Arduino. By adjusting the potentiometer, I should of course get values between 0 - 1023 (10 bit ADC). However, no matter how I adjust the potentiometer, I always get 1023, so I think the sensor is "overshooting" all the time. I have tested the potentiometer previously and it works fine. I suspect there is something wrong with the wiring diagram.
Any ideas? Thanks in advance.
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In the circuit i cant see where the arduino is connected to the power source
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Solution
In the circuit i cant see where the arduino is connected to the power source
If you're consistently getting a value of 1023 from the ADC, it suggests that the voltage at the ADC pin is always at or near the maximum (5V for a typical Arduino). Here are a few things to check:
i also suggest you check the datasheet of the photo diode to confirm the manufacturers requirements