Why am I not getting the expected gain out of my op-amp?
where Rin is 1.8 kΩ and Rf is 27 kΩ. My Vin measured across the photodiode is ~0.14 V in ambient lighting conditions. I have also connected my op-amp to 3.3 V from a Pi Pico and to ground. I would expect to get Vout = -(27/1.8)·0.14 V = -2.1 V. However, when I read the output using a Raspberry Pi Pico ADC pin, I get 0.34 V. Is there something off with my op-amp here? I also replaced the op-amp with a fresh one and got the same behavior.
My goal is to get around 3.3 V out, but no matter what I do, I can't seem to get above 1 V out of my op-amp. Am I missing something?
Update: I've got everything working now, The issue was that my photodiode was a reverse bias diode. I got it working using the circuit from this answer although Spehros answer to this would have worked for any forward bias diode.