chipKIT® Development Platform

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USB Problems

Created Fri, 06 Apr 2012 21:50:00 +0000 by vintageguy


Fri, 06 Apr 2012 21:50:00 +0000

I am using the USB MSD library, and am having the following problems.

When I start up the max32, I can plug in a USB MSD card and it is detected. But very fast, it may seriously ruin the timings, so that any USB communications over the terminal is lost. the chipkit, appears to freeze, but it's "receiving" data, according to the light indicators, and sometimes sending data, according to the light indicators. But nothing is viewed. Shortly after, the max32 freezes.

I'm using a timer interrupt, which is timer4, and the Perhipheral clock is set to the bus clock 80MHz (I need fast perhipheral).

I've disabled the JTAG, by setting it to 0.

I've initialized the RTCC library.

I am using the following pins.

INT3 RA0..RA2 RG12


Not using a timer, is not an option. I also need a fast timer, preferrably around 100ns one, at minimum 250ns one. I am trying now with a slower one 1/50KHz. That does not appear to matter,

Any suggestions?


Fri, 13 Apr 2012 17:36:45 +0000

Ok, after a long period of debugging ... without a proper debugger. I came to understand, that it was shortage of memory that caused it. I was trying to read "big chunks" at a time ... which caused the USB library to freeze, and not give any message as to the failure.