QTR-8RC reflectance sensor (with Arduino Duemilanove)

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1

Hi,

(1) I am using QTR-8RC reflectance sensor with Arduino Duemilanove. I followed QTRRCExample.ino and I connected sensors 1 to 8 to digital pin 3 through 10. However, what I got is like this

Display values: 9 0 9 9 9 9 9 9
Sensors number: 7 8 1 2 3 4 5 6

The third “9” represents the first sensor and so on. Sensor eight never changes values (other sensors are calibrated successfully).

Can anyone tell me why this happen? Thanks!

(2) Also, I want to use the sensor to control a servo. I am going to use something similar to Arduino servo knob’s code. I am really new to Arduino and I do not know how to use the values I obtained to control the servo. That will be very helpful if someone can show me sample code about the control. Again thank you very much for all help!

2

Hello,

Could you try displaying the raw sensor values of the array by using the call sensors.read() instead of sensors.readLine(). Also, could you post a simplified version of the code that should work but does not display the expected values.

For your second question, the Knob example is a great place to start. You can store the values you read with the QTR sensor and manipulate them to command the servo.

- Jeremy