Visual Light Sensor
Visual Light Spectrum Sensor Arrangement
Current-limit resistor for Red and Blue LED’s: 330 ohms. (Same as other LED’s, short pin goes to ground)
Load resistor for TEPT4400 Visual Light Spectrum Sensor: 20k ohm or 43k ohm. (long pin is the ground pin)
Either resistor will work for the Light Spectrum Sensor. You can test with both and decide which one gives your specific rig better values. A larger resistance gives a larger voltage output. It is also recommended that you slip a short section of black heat-shrink tubing onto the Light Spectrum Sensor. This will help shield it from output fluctuations due to changes in ambient room lighting.
A schematic of the setup is given below.
The sensor has green tape on one of it's legs while the LEDs do not. Since they all look very similar you will want to keep them separated.