Hi, I am trying to design the butterworth filter using CMSIS library in cortex-M4 processor.. i know how to do it in MATLAB(and even fdatool), but i don't know anything about CMSIS library.. i saw the arm_fir_filter example and i understood it.. but my requirement is IIR filter design.. i am not getting any example code or any links how can i design a Butterworth filter using CMSIS library..
I know we don't have Butterworth API in CMSIS-DSP, so which one i should use Biquad Cascade IIR Filters Using a Direct Form II Transposed Structure or Infinite Impulse Response (IIR) Lattice Filters
please can anyone help me out to solve this problem?
as written here www.iowahills.com/A8FirIirDifferences.html , basically you can implement your butterworth filter based either on FIR or on IIR filter. I think it really depends on how you design your Butterworth.
These links might help you: ocw.mit.edu/.../lec08.pdf
www.analog.com/.../MixedSignal_Sect6.pdf
Thank you very much for your reply.. Even i have read that we can implement IIR filter using FIR filter.. but the thing is i have very limited knowledge in CMSIS library. I dont know how to use it.(from the example i learnt how to use FIR filter in CMSIS). So it will be helpful if i get example code or flowchart of how i implement the IIR filter using CMSIS API's...
I have already done the coding, but i don't know whether i have done correctly or not.. if you want i can share my code with you. can you verify it for me, please?
the corresponding documentations for IIR filters can be found here www.keil.com/.../group__group_filters.html
And the source codes of all filter functions are located in C:\Keil\ARM\PACK\ARM\CMSIS\4.5.0\CMSIS\DSP_Lib\Source\FilteringFunctions
Since CMSIS is an open source project, you might discuss and find some useful information directly on ARM github github.com/.../CMSIS_5 github.com/.../CMSIS
Ya, thank you.. Based on the documents available in the internet, i have done the coding. how can i verify that my code is correct or not?
How do you check if a lamp works? Isn't the traditional way to turn it on and see if it lights up, and stays lit at a constant - and reasonable - intensity?
The way to test a filter is obviously to send in a signal of varying frequency and check the response of the filter - if you get the correct response your program works. If you get a different filter response then it doesn't.