I’m using some solar post lights from Lowe’s and modified them:
I removed the solar control chip + LED, and install a more powerful LED bulb, power under 12VDC:
Since the solar panel exist already and not used anyways, I thought I will try to use it as an ambient light detector to measure the voltage with the Arduino. Apparenty, under full bright sun, voltage is 4,5V
So i don’t need a voltage divider since max voltage is <5V, but should i put a series resistor ? If yes, what value?