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Bar Code-Scribbler — Parallax Forums

Bar Code-Scribbler

n3lskn3lsk Posts: 2
edited 2008-04-10 18:18 in Robotics
I wrote a simple program using the GUI interface for the Scribbler·to demonstrate the bar code for my Grandson. I just had the Scribbler roll over a bar code for 3 and turn right. I can't get the program to work. Any suggestions?

Comments

  • ercoerco Posts: 20,256
    edited 2008-04-09 16:46
    Check that your Scribbler's two bottom IR sensors work properly, mine did not. Run the program that lights the green LEDs according to what the sensors see, and push the robot over a 3/4" black line on a white paper. Verify that it reliably detects the black/white transitions. Mine could not easily detect white . Unfortunately this is a hardware setting and so software calibration is available. I took a hobby knife and carefully opened up the four holes on the bottom for better IR emitting and detection, and that helped. Don't scratch the clear lens of the IR LEDs or phototransistors, that will hurt your results.

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    ·"If you build it, they will come."
  • n3lskn3lsk Posts: 2
    edited 2008-04-09 17:36
    I checked the sensors and they are working properly. The program I wrote just had the Scribbler move forward at 50:50 and then I used an if then box. If it sees a 3 either way then make a right turn. Do you need a pause or any other detail I may be missing? I am new to programing and not sure of some of the details.
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2008-04-10 18:18
    Success with barcode reading depends a lot on timing. Many problems occur because the Scribbler program is not ready to read the barcode when it first encounters one. You might also try varying the forward speed to see if that helps. Can you post your .scb source code?

    -Phil
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