Let's say I have a photodiode, a shift register (74HC595) and a 5V source, and I connect these as:
5V source -- photodiode -- shift register data input.
(And other voltages to feed the register clock etc)
Do I need a resistor with the photodiode, or will it suffice to put the photodiode before the shift register?
What I am trying to do here is essentially use the photodiode as a switch which allows the register input to be set to 1 only when light falls on the PD.