Linking CMSIS DSP on LPC825 Target

[brentsinger]

Hi, I have a need to calculate FFT on sensor data, using an LPC825 target, testing on 825Max devbrd. 

I believe the right approach is CMSIS DSP Math libraries. I am able to get the source to compile in my project, but the flash requirement is 333% of that in the LPC825. Now trying to use 'headers' with link to compiled .a library, to make sure i can it to fit in the 825. 

I followed the instructions:

- import that libraries into MCUXpresso IDE

- Run new project wizard, select the Library Headers:

The project complies initially, but when I add the code from this example

- https://arm-software.github.io/CMSIS_5/DSP/html/group__FrequencyBin.html

I get this error, which is not surprising, as I've not linked the library yet.

In settings I have these libraries in the new project by default:

And no libraries or lib search paths. So adding:

- libCMSIS_DSPLIB_CM0.a

- C:\nxp\MCUXpressoIDE_11.7.1_9221\ide\Examples\CMSIS_DSPLIB\CMSIS_DSPLIB_Latest\CMSIS_DSPLIB_CM0

Doesn't successfully compile: 

I'm pulling my hair out. Please help before I am bald!! Thanks, Brent.

[brentsinger]

Hi Alice, this didn't have any effect. Error changed to:

[Alice_Yang]

Hello @brentsinger 

You can refer to "Using CMSIS-DSP with MCUXpresso SDK and IDE":

https://community.nxp.com/t5/MCUXpresso-General-Knowledge/Using-CMSIS-DSP-with-MCUXpresso-SDK-and-ID...  

BR

Alice

[brentsinger]

Thanks, This seems to be a move in the right direction...

But the SDK I generate doesn't actually have the /lib/libCMSIS_DSPLIB_CM0.a directory or file in it. Or the examples, even though I have selected CMSIS DSP Library in the SDK generation.

I think it's for an older IDE version and changes have been made since. I will try again with fresh eyes today.

Is there someone in the FAE team who might be able to quickly put a "Hello World" together for me with the libCMSIS_DSPLIB_CM0 library linked? My target is the 824MAX development board, archive and send it thru. I might even send you beer. Otherwise I'll keep trying...

[frank_m]

> But the SDK I generate doesn't actually have the /lib/libCMSIS_DSPLIB_CM0.a directory or file in it. Or the examples, even though I have selected CMSIS DSP Library in the SDK generation.

This was the default case with another vendor's MCU I made a few DSPLib applications for.

The ARM DSPLib comes with sources, and examples. Just use the source files instead and include them into your project, perhaps take a DSPLib example as template.

[Alice_Yang]

Hello @brentsinger 

How change libCMSIS-DSPLIB_CM0.a to  CMSIS-DSPLIB_CM0 ?

"

"

BR

Alice

[frank_m]

Yes, that would be standard behavior for GCC.
The "lib" prefix and ".a" suffix are automatically added to every name specified with "-l<lib>".
Not sure what Eclipse/LPCXpresso adds to the mix.

I would try to add the library via Drag&Drop, and add the library folder to the search path list.