QTR-8RC does not work

Hi. my QTR doesn’t want to work :wink:
I’m using arduino uno and the QTRRCExample program and minimum and maximum are always 2500 and then with readLineBlack always 0.
All the connections are well placed and the distance from the sensor to the black and white background is 3mm.
Is there any way to check if the IR LEDs are broken with a voltmeter? or in some other way?


Can you post some pictures of your setup, including ones that show all of your soldered connections? A video demonstrating how you are testing the array might also be helpful. The forum does not allow users to post very large videos, but it does work well with videos linked from other sites (like YouTube or Vimeo).

What happens if you test the raw values example from our QTR sensors library?

- Patrick

I think I know what happened.
It has been used with 5v when the 3.3V jumper was attached and now it does not return any value.
The raw values returns 2500 always.

Powering the array with 5V while the 3.3V BYPASS pins are connected can cause the IR LEDs to draw more current and burn out. Unfortunately, the raw values example only returning 2500 (indicating minimum reflectance) makes it appear more certain that is what happened.

- Patrick