I am trying to mate my light sensor to Arduino, but I am not sure about what connections to be made or rather the values for resistance for R4 and R7. R4 is part of the sensor and I am thinking I need R7 for the Arduino.

 

hi Light,
Why are you concerned about those two resistor values?
The signal levels at A0 are low level.
E

 

A combination of values should get me 5 volts on the analog pin, but changing R4 or R7 changes the voltage in an unpredictable way.

 

Hi,
OK,
Assuming the signal limits, what will be the maximum Photon intensity and I assume that you would expect a +5V maximum signal on the ADC input at that Photon level.

Could you explain the purpose of the project, so that I can get a better understanding of its use.

E

 

I don't know. I have to familiarize myself with a datasheet, because I forgot where I left-off with this circuit.