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Pan/Tilt servo issue

Pixy Hardware
#1

I have a new Pixy & Pan/Tilt servo. I cannot seem to get the servo demo working properly. This is my 2nd Pixy. One is for a prototype project, the pan/tilt set-up is for experimentation. However, when connected, the servos (esp., the tilt servo) run to their max and stop (as if “seizing up” if it were alive). When pluigged in, I can hear one servo running even when it is at its max rotation & PixyMon is turned off. I have been working through the various possible problems but, apparently, I am missing something. Can, e.g., the servo program be re-loaded? (I have reloaded the newest firmware).

Suggestions?

#2

Hello Frederick,
Sorry for problems. I’m not sure what you mean by reloading the servo program. The pan/tilt demo is in the firmware, so reloading the firmware reloads the pan/tilt demo. I assume you’ve seen this:

http://cmucam.org/projects/cmucam5/wiki/My_pantilt_is_acting_sort_of_crazy

You might also look at the fastener that attaches the pushrod. (See step 25 here: http://cmucam.org/projects/cmucam5/wiki/Assembling_pantilt_Mechanism) If it is tightened down too tight, the tilt movement is much more difficult.

Let me know what you find.

Edward

#3

Thank you for your reply.

The clue was in this line on the site under the topic “Powering Pixy”: “… the servos won’t function (they’ll probably move to one end of their limits and buzz).” That is exactly what was happening. This required a new cable. However, the cable was working fine when a Pixy (alone) was attached to an Arduino; it just caused a problem when attached to the servos. Hence, it was not the first fix that came to mind.

Thank you again.

#4

That’s good news :slight_smile:

The servos start behaving strangely around 4.3V, whereas Pixy will work fine down to 3.9 volts or so. Some USB cables if they are too long or if they have thin gauge will have a too much voltage drop and cause issues with the servos.

Glad you got it working!

Edward