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Unread 11-11-2014, 15:48
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Alan Anderson Alan Anderson is offline
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FRC #0045 (TechnoKats)
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Re: battery voltage vs current

Quote:
Originally Posted by pribusin View Post
That's all great info. Is this documented somewhere? I'd like to get our programmers reading up on this stuff asap.
Details are still being tweaked as Beta Test teams identify areas that need attention. I'm afraid that official documentation will have to wait until after the Beta Test period is over. That basically coincides with Kickoff. We can still answer questions and give useful information; we just can't give you access to any unpublished documents.


The cRIO's brownout protection strategy relied on a relatively slow measurement of battery voltage through the analog input module. It often could not react quickly enough for the system to survive a sudden voltage sag. The roboRIO voltage-measurement hardware is much faster, and there is a lot more room for fanciness in the FPGA. For example, the roboRIO's PWM outputs will actively turn the motors off upon a brownout instead of just stopping the signal to the speed controllers and waiting for them to time out and go into disable mode.