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Problem with IR detection — Parallax Forums

Problem with IR detection

MrMikeMrMike Posts: 4
edited 2005-09-21 03:10 in Robotics
Hello all,

I've recently programmed my Boe-Bot to navigate on its own via IR detector circuits.· I've noticed that it tends to turn left more than right to correct itself from objects.· First, I made sure the servos were turning at the same rate (for my servos, this means 850 on one side, 690 on the other).· Robot goes perfectly straight, so then I changed the resistor that's in line with the left IR LED from 1k ohm to 470.· This made the left side IR detector more responsive.· Tried cleaning the LED, checked connections, tried different lighting, adjusted the heighth of the LEDs.· Although this essentially put a "bandaid" on the problem, I want to try and understand why it is that one side seems to be more sensitive than the other.· Should I change the amount of time that a pulse is sent to the LED?

Just wondering if anyone had any thoughts/ideas?

Thanks

Comments

  • edited 2005-09-21 03:10
    Start by going back to equal value resistors in series with both IR LEDs.

    First, verify that you are using the same Frequency argument (38500) in both FREQOUT commands. Also, check to make sure both the IR LEDs and IR receivers are pointed level to the ground and pointed outward at the same angle. If all that checks out, here are a few tests you can try to isolate the other possible culprits:

    Use the Debug Terminal to find out how far away the left IR detector can see an object (like a white paper target). Repeat for the right IR detector. Then, disconnect power, swap IR LEDs, reconnect power, and test again. Repeat the test after swapping IR detectors, and repeat the test again after swapping resistors. Last, but not least, repeat the test after you have swapped the order of the code blocks for left and right IR detection.
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