FXLC95000 FFT

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FXLC95000 FFT

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majidhamidi
Contributor I

Hi, I am working on FXLC95000 and trying to modify the example code  "GetAccelData" to implement 16 bit FFT analysis.

My program first stores 1024 data points in a global variable then calls FFT16 in the usertask, but it doesn't go through FFT (as attached).

I am guessing the problem is the allocated memory which is 4096 bytes for this task. Hoever, when I change that number in task setting,

the Coldfire still freezes when it reaches to FFT16 function call. Any idea?

Original Attachment has been moved to: GetAccelData_main.c.zip

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jimmcglasson
Contributor III

Majid,

There are a number of things to consider here.

First make sure that you have enough RAM to allocate everything you are trying to allocate. The fXLC95000 only has 16K RAM. The amount required by ISF is documented in the release notes.

Second make sure, if you are using floating point math in your FFT routines, that you have enabled Software Floating emulation in the compiler settings- this is not enabled by default in our example projects.

Also make sure that the stack size for the task that is calling the FFT is large enough to handle all the local variable stack allocations.

Again, this might need to grow if you are calling math library functions.

-Jim

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