Digital Filters and Convolution in dsPIC or any uController

[scaven]

Hello,

I have a question that I hope I can ask clear enouph, here goes...

When programming for a low pass digital filter, how do you implement that onto an input signal, say a waveform. Do you take the FFT of the signal after A/D and multiply them together, or do you convolute them in the time domain? What is the proper way?

The reason I am asking is I want to implement a digital filter in a dsPIC using either C or Basic. I am not too familiar with Assembly. How would one code for that, it is confusing me! Can someone please give me a simple example or explanation for an implementation in a language other than Assembly? I understand the theory behind it, just have no experience in implementation.

Thanks for the help!

 

[epp]

Re: Digital Filters and Convolution in dsPIC or any uControl

Look at Microchip application notes section. There are examples for IIR and FIR filters (I've forgtot wheter theay are for C or assembly).

Good example in C is TI's introduction to oversamplig theory:
https://focus.ti.com/lit/an/spra461/spra461.pdf . Here you will find implementation of Moving average low-pass filter for ADC.

 

[scaven]

Re: Digital Filters and Convolution in dsPIC or any uControl

Thank you very much for the help, thats what I was looking for!

Chris