So, instead of buying a nightlight for my kid's room, I decided I could do a much better job of it. This nightlight cycles through 1500 colors over 7 mins and turns on when it is dark and turns off when it is light. It is also small enough into small objects to add effect. Step 1: Setup Arduino First create a voltage divider with the photoresistor and the 10k resistor. You can choose any ADC pin, I used 20. ...