QTR-8RC Reflectance Sensor Array

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1

I see in QTRRC Example, they say that “The emitter control pin can optionally be connected to digital pin 2”, but I dont know what is emitter control pin ?

2

Hello.

The designated emitter control pin from that example should connect to the LEDON pin on the QTR-8RC reflective sensor.

  • Grant
3

So how about pin 13:
"The setup phase of this example calibrates the sensor for ten seconds and turns on
// the pin 13 LED while calibration is going on. During this phase, you should expose each
// reflectance sensor to the lightest and darkest readings they will encounter "
pin 13 it’s not connected to LEDON?

4

Pin 13 is the Arduino’s built in indicator LED. It is used for visual feedback and is not connected to the LEDON pin.

  • Grant
5

aha, i understand. But when I run that QTRRC example by Arduino Uno, Serial Monitor print like that:
2500 2500 2500 2500 2500 2500 2500 2500
2500 2500 2500 2500 2500 2500 2500 2500

0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0
…
just 0 for all
Of course I’ve slided sensors across a black tape surrounded by a A4 page.

6

Hello.

I suspect that you are not calibrating correctly. Can you try printing out the raw sensor readings?

  • Grant
7

Hello,
I would like to know if it’s possible to use the QTR-RC to follow a red line and a green line on a white background.
Differentiating between red and green is hoped for but only optional. I would be happy to just be able to follow either a red or a green line regardless of which one is which?

Would the 8A be more suited to color recognition than the RC ?

Thank you

8

Hello.

Our line of QTR sensors are not intended to differentiate color, so I am not sure if they would work for your application. How well these sensors will distinguish between two surfaces is dependent on the IR reflectivity of each surface. You would have to test it to see how the sensor responds to the different colors.

  • Grant