Filtering digital data

Z

Zener_Diode

New Member

• Mar 26, 2007

• #1

Hey.
I want to filter digital data. for example: I have an analog signal. with A/D I convert it to degital one. Now I have in PC list of numbers that represent analog signal.
I want to write a program (in C or visual C) for LPF,HPF,BPF,BSF.
does someone know how can I do it?

Thanks ahead

 

evandude

New Member

• Mar 26, 2007

• #2

this is something you'd cover in a DSP course. I don't know how much luck you'd have trying to pick it up from scratch in a short period of time...

but you might start by reading about FIR/IIR filters:
https://www.dspguru.com/info/faqs/firfaq.htm
**broken link removed**

You might be able to implement filtering without much real knowledge of how things work, if you just use design software to design your filters. The first FAQ I linked has some links to software you can use.

 

Nigel Goodwin

Super Moderator

Most Helpful Member

• Mar 26, 2007

• #3

Try looking up DSP's (Digital Signal Processors) and see how they do it - MicroChip have a DSPIC range, with examples in the application notes.

 

Z

Zener_Diode

New Member

• Mar 26, 2007

• #4

I want to make this DSP without chip, on by programing in C.

 

evandude

New Member

• Mar 26, 2007

• #5

All you really need to do for actually implementing the filter is feeding in your input data one sample at a time to a buffer, and doing some simple math with the filter constant arrays. It's certainly possible, even easy, to do on a computer in C, in the DSP course I took a few years ago we did just that, using the sound card for signal input and output.

 

Sceadwian

Banned

• Mar 26, 2007

• #6

What is the frequency and bandwidth of the signal you're supposed to sample?

 

Z

Zener_Diode

New Member

• Mar 27, 2007

• #7

BW=200Hz (1Hz-200Hz)

 

Sceadwian

Banned

• Mar 27, 2007

• #8

That's nothing, an MCU can do that easily.