For Arduino Nano
This device checks the quality of light sources such as LED lamps. These lamps are often flickering, usually on the 100-120Hz frequency (doubled frequency of power grid).
Flickering is displayed with the row of 10 leds (Kingbright DC-10EWA). The number of blinking LEDs is proportional to the flicker rate.
Light sensor used: Avago APDS-9006-020
It's possible and even better to use APDS-9007, because of higher range. It needs some testing.
Leds connected to digital pins from 2 to 11
Sensor connected to pin A6
Button connected to pin 12.
Ask me if you need user manual