Newbie: How to create a low pass that can be exported into c++?

Hi everyone,

I am a c++ developer and COMPLETELY new to matlab. I read that matlab can help me with low pass filtering a signal. my signal has a x and y int16 component and in my c++ application one can change sample rate and cutoff frequency. I have watched a tutorial and read some posts, i.e. http://www.mathworks.com/matlabcentral/answers/37975-how-to-design-an-iir-low-pass-filter-with-matlab but I am still stuck.

my goal is to have a c++ function that i can just pass my signal data to on the fly, the signal is not prerecorded. so i was thinking one could initialize a butterworth low pass with sample rate and cutoff frequency like: fdesign.lowpass('N,F3db', 3, 0.5, 2000); and then continuously run the incoming data through the filter. when the user changes the cutoff frequency the filter would be reinitialized.

i know how to create c++ code from a matlab project, but can someone point me in the right direction how the matlab functions should look like?

thanx!!

Answer 1

[Wayne King]

Which MathWorks' products do you have? If you have MATLAB Coder, the Signal Processing Toolbox, and the DSP System Toolbox, you can easily write a filter design and implementation routine in MATLAB that you can port directly to C/C++ code with codegen

Answer 2

[Martin]

i have Matlab R2011a with the coder, the signal processing toolbox and the dsp system toolbox. and i will read some more tutorials on how to combine them. could you provide some sample code or step-by-step instructions that i can start with? thanx!