[Mike Bortfeldt]

Your problem definitely sounds like it is somewhere within your interrupt code. Unfortunately without actually seeing your code, it is very difficult to guess where the problem may lie. While this may seem obvious, are you using a printf from within one of your ISRs to debug your code? If so that could be causing some of your problems. Also, as Tim Craig mentioned, make sure you are using all the updated code IFI posted as they do fix issues in the silicon (updated libraries, modified linker script). Unlike his team though, we never saw any problems after applying the updates that was not attributable to our own code.

You may find that even after these issues are resolved; your GTS code will not always count properly as there will be some uncontrollable delays in interrupt processing when the User Processor is communicating with the Master Processor that may throw off your pulse calculation. You may want to think of an alternative way to determine pulse width. Just for reference, as kind of a fun assembly language project, I used a PIC 12F508 (< $1) to calculate the pulse width and then toggle the state of a digital output on a forward pulse, and a different output on a reverse pulse. This allowed for total control over the timing and the output could be easily read by interrupts 3-6 on the RC. It worked fine during some initial bench testing, but as we didn’t use any gear tooth sensors on our robot, I never got a chance to fully test it. You are welcome to the code if you would like it.

Mike

Oops, a couple of minutes late replying...