To give users more flexibility, I think we should offer heterogeneous outputs and inputs:
LED outputs: we can vary the resistors in the circuit to give users LED channels with higher maximum output. This would be useful for more intense white light, or more intense IR for very turbid situations.
PD inputs: varying the feedback resistor (and accompanying cap) across the channels would allow users to amplify weak signals (ie. backscatter, or high turbid environments). This has the same effect as including a potentiometer across the op-amp. Another application: when using the GLI2 method, the 180 pd receives a very high signal even with modest LED output, which will quickly can hit the ADC's limit. The modest LED output means that the 90° signal is quite weak. If this Rf was half the size (or less), we could increase the LED output -> higher 90° signal.
For both, it would be worth it to only discuss ratios: i.e. instead of saying "this has a 250k ohm rf" we say "it's N times more sensitive than channel 0"
To give users more flexibility, I think we should offer heterogeneous outputs and inputs:
For both, it would be worth it to only discuss ratios: i.e. instead of saying "this has a 250k ohm rf" we say "it's N times more sensitive than channel 0"