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Unread 17-02-2012, 08:34
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Re: Help! RobotDrive Error in all 3 languages

Quote:
Originally Posted by bdbayes View Post
We discovered that one side was putting 2.27 volts through the control circuit while the other was putting 0.67 through on the other side.
Can you clarify on this more? I assume what you are doing is taking a multi-meter and measuring the voltage on the PWM Signal Wire to Ground. First, this is going to be inaccurate as the PWM frequency is pretty high and your multi-meter may not interpret that as correct, unless you have a true RMS meter. I may be wrong on this point, someone correct me if I am. The better test for this would be to use an oscilloscope and measure the pulse width.

However, this may be a non-issue anyways depending on your electrical and software setup. If you are running the basic tank drive software with all the CIM motors hooked up normally (red-red, black-black) one side will need to be inverted from the other. If this is done in software one side will get a different PWM signal than the other, and this can be easily determined by looking at the speed controllers while driving forwards. If the speed controller led's for the left side are different than the right side that means they are inverted in the software. Which is perfectly fine.

You didn't specify your actual drive-train setup, are you guys doing 4wd or 6wd?

I suspect that you have one or more of the following problems: a) You still have binding issues in your drive-train b) Bad weight distribution on your wheels c) Not all wheels contacting the ground.

If you see the same problem in all 3 programming languages using the default code (disregarding many other teams using the default code without issue) the problem is probably not the software. When you drive fully forwards and the speed controllers led's are constantly on (green or red) that means the software is putting out a full throttle command.
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