Hi,The QRD1113/14 reflective sensor consists of an infrared emitting diode and an NPN silicon phototransistor mounted side by side in a black plastic housing.
Here is the schematics from the datasheet
And some images I cut and paste from the datasheet below:
It is obvious from the schematic that pin 3 is VCC and pin 4 is ground. Pin 1 is the collector which gets connected to VCC?
And pin 2 the emitter gets connected to my analog input. Is this correct?
Sorry for the dumb questions but I got to make sure this is right.
Do I need a resistor on any of these pins? If so what are they used for exactly?
The normalized current vs. distance curve is also below.
Thank in advance,