I am building arduino laser transmitter.
I have modulated laser blink, however the photodiode detection is not really sensitive to the beam (I would need to spread detection at higher range). I tried to use photoresistor, but it was slow discharging making bits in graph unreadable.
How can I increasy sensitivity of the photodiode (and possibly reduce effect of daylight)?
- currently using arduino circuit with PP75 photodiode and 10 Mohm resistor (there was no detection when using lower resistors..)
Maybe I have badly connected circuit? Or do I have to use some MOSFET? (but I am not sure how to use it properly...) thank you for advice. Photos shown bellow
here is my previous result of using circuit with photoresistor. The only problem with this was that the values was dropping slowly, making the output unreadable at higher speed. I thought a photodiode would fix this, but the responsivity is not hight enough. How can I improve my circuit with photodiode to get a simillar result as if using photoresitor except I would get these values changed quicker as on img2 ?
The deviations at bottom of the graph is a lamp switching on and off so its good because it doesnt affect the laser blinks.