Hooking up QRD1114 line sensor
Few days ago one of our new members asked for help with QRD1114. I decided to answer in form of walkthrough, so others can benefit from it as well.
OK, should we start?! The QRD1114 line sensor (reflectance sensor) is easy to use. Personally, I can recommend it.
Where should we go first? Right, datasheet. We will need to dig some information out of it:
- Continious forward current of emitter = 50 mA
- Forward voltage of emitter = 1.7 V (max)
Last two values are necessary for calculating resistor (see end of article).
The basic circuit for this sensor should look something like this:
Warning!!! Pins on schematic are not arranged as phisical ones! Refer to drawing and datasheet!
You will connect your power supply across V0 and V+. Out will go to ADC input of microcontroller. Depending on supply voltage and configuration of your emitters (if, say, you will use 3 line sensors, you might want to connect them in series or in parallel) you will need to recalculate/rearrange resistor which is in series with emitter IR LED. Here is nice walkthrough on how to do that.
Wasn't that easy? :D Good luck!