Pic DSP Bandpass filter

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SHORTCIRCUIT
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Pic DSP Bandpass filter

Post by SHORTCIRCUIT »

I am interested in using the DSP component in V5, however not being an engineer and unfamiliar with the DSP terminology, I find it very difficult. Particularly interested in bandpass filters in the voice frequency range. Does anyone have an example they can post which I will use to learn from. I have a PIC 16F88 in mind. Will this be fast enough to handle a bandpass filtering function in that frequency range or is the 16F88 to slow.

I have been watching the site for some time now, but no examples yet. I played with some of the matrix samples but I am still fumbling as the explanations are very to limited for someone of my limited experience level. I know what a bandpass filter does but I am unfamiliar with the terms used to setup the DSP component. An example of a bandpass filter would go a long way to help me understand the "how to do's" of bandpass filters. I need this badly as I have a burning desire to do some experimenting in this area. Are there any YouTube stuff on pic filters or any matrix training videos on filters, etc. My searches have not revealed any.

Thanking you in advance.

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Re: Pic DSP Bandpass filter

Post by SHORTCIRCUIT »

Hey Benj, don't anyone on the matrix staff have a Bandpass filter example?

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Re: Pic DSP Bandpass filter

Post by kersing »

The DSP components are very new. All example code there is has been made available, attached to this message, so if you haven't found what you need in that archive it does not exist yet.

Based on my (limited) experience with DSP code I think your target processor is to slow for a real time bandpass filter for voice frequencies (300-3000 hz).
“Integrity is doing the right thing, even when no one is watching.”

― C.S. Lewis

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Re: Pic DSP Bandpass filter

Post by randomrichard »

Hi

I am halfway through a book by Steven Smith (http://www.dspguide.com/editions.htm). It has taken me up to DSP, discrete signal processing, and through convolution/deconvolution and simple filters without maths and with clear understanding: - marvellous diagrams. I think the old edition is available as a free download. Strongly recommended.

Richard

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Re: Pic DSP Bandpass filter

Post by Nico595 »

Thank Richard,


I design a DSP component with compressor, limiter, delay. It s easy, but for audio filter it s more hard ^^
If you have experiences and ideas with DSP, thank for your advices.

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Re: Pic DSP Bandpass filter

Post by randomrichard »

Hi Nico
No, I've only just started - I have converted Smith's (very) Basic code into VB.NET to see how it works and now have a working simple spectral analyser (his tables 8.2 and 8.3) on my PC using test files from an Arduino saved in Excel. My aim is to use a 12bit ADC, say on the dsPIC30F2011 and use its DSP to compress "chirp" signals detected by an echo locating (sonar) system. This improves precision at the cost of a loss of spectral data. Smith covers this topic as well as filters, etc. Amazing book. If my system works works I won't tell anyone how! But based upon past experience I am more likely to reveal what went wrong...

Now that Flowcode 6 has DSP functions and 12bit ADC I am in the process of transferring code from the easily-programmed Arduino Due, on which I have been working so far, to PICs, hoping for more speed and flexibility.

Steven Smith's philosophy, which is absolutely correct, is that DSP is the 21st century technology replacing transistors. We didn't really know how transistors worked doing analogue electronics. Nor do we really need to know how Fourier analysis and the FFT works using processors
Richard

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