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Rich LeGrand, 05/09/2014 01:21 pm


My pan/tilt is acting sort of crazy

The pan/tilt mechanism should track objects smoothly. If it doesn't, here are a few things to try/check.

1. Try a different USB cable

Powering servos over USB is great because you don't need to worry about batteries, but there can be problems with not enough voltage reaching the servos. Always use a USB cable that's 3 feet or shorter, and if it's still having problems try another cable if you can. USB cables aren't created equal -- some have flimsy-gauge wire that can cause problems.

2. Check to make sure there is no mechanical binding

Unplug Pixy from power/USB and gently check the pan axis by moving it back and forth over its entire travel. It should move fairly easily and smoothly. Then test the tilt axis by moving the servo horn back and forth (not Pixy!). It too should move fairly easily and smoothly and not bind on any cables.

When Pixy is plugged into the USB cable, make sure there is plenty of cable for Pixy to look up and down, left and right.

3. Check the connections

This is an obvious one, but make sure the connectors that plug into Pixy are secure and fully engaged (you shouldn't see any of the terminal posts on Pixy -- each servo connector should completely cover the terminal posts on Pixys servo connector.)

4. Does the pan/tilt seem to avoid the object?

That's not good! But it's usually caused by the pan and tilt servos being swapped where they plug into Pixy. Try swapping the servo connectors where they plug into Pixy so they are correct.

5. Do you get a good solid rectangle in PixyMon when running the "pan/tilt demo"?

If the rectangle changes shape rapidly or you see lots of rectangles (detected objects), Pixy will have a hard time tracking. You should probably re-teach. Or you may need to adjust some parameters -- consult this guide to learn more.

6. Test the servos

Run PixyMon and hit the stop button (upper left corner of PixyMon). In the command window type this, hitting <return> after each line:

rcs_setPos 0 1000
rcs_setPos 0 0 
rcs_setPos 1 1000 
rcs_setPos 1 0 

This should exercise the pan servo first then the tilt servo. The movement should be smooth and rapid. If not, make a note of which servo is acting strange. and send us an email describing your experience ().