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Unread 09-01-2008, 10:25
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Kevin Watson Kevin Watson is offline
La Caņada High School
FRC #2429
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Re: New C18 3.0+ Compatible FRC Code

Quote:
Originally Posted by eugenebrooks View Post
Kevin,

Did anything turn up on your inspection of the provided
code with respect to a possible source of the 8.3 volt bug?

With all the interrupts we will have flying this year,
we are sweating it, although we will get a good six
weeks to see if it surfaces again.

Eugene
While testing the new library code, I discovered that I could induce the 8.3 volt bug pretty reliably (I had never seen it before), and more importantly, eliminate it by initializing the entire RAM array to zero at boot time (something the C18 startup code does not do and IFI only partially does). I need to get in with a hardware debugger to see what's going on, but I haven't had time to build the custom cable I need to use the internal debugging header. I hope to get to it sometime in the next week.

If it's of any interest, I did notice the new code and compiler seem to handle high interrupt loads better than with the 2.4 compiler. I setup my ADC code to sample at 6400Hz (each sample generates an interrupt) while generating a few hundred more interrupts/sec with a encoder. The RC had no problems sending a bunch of telemetry using printf() under the load.

-Kevin
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Kevin Watson
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