Re: Basic info needed regarding filters (FIR)

On Sat, 24 Nov 2007 11:41:08 -0600, Vladimir Vassilevsky
<antispam_bogus@xxxxxxxxxxx> wrote:



John Larkin wrote:

On Fri, 23 Nov 2007 12:43:10 -0600, Vladimir Vassilevsky
<antispam_bogus@xxxxxxxxxxx> wrote:

Here is the basic realpole filter which is simpler and appears to have
almost identical response:

const u8 order = 4;

s32 LPF(s32 x)
{
static s32 z[order];

for(u8 i = 0; i < order; i++) x = z[i]+= (x - z[i])>>6;

return x;
}

Making digital filter as the simulation of an analog filter is rarely a
good idea.


I've sold over 3000 of the temperature controllers that use this
filter.

McDonalds serves somewhat 10 billion meals per year. But this fact doesn't
make those meals taste any better or worse :)

Selling things for high prices to high-end customers, in volume, for
years, bug-free, means we're doing exactly what we want to do. Any
other criterion for engineering quality is, literally, academic.

Why whining about the Evil Empire of Bill Gates then?


Because it's slow, bloated, and bug-ridden, from a company run by
sociopaths who crush competition out of sheer ruthlessness.


I am sorry if you didn't understand 3 lines of trivial C code without
comments. It would be a good idea to do some learning before suggesting the
advanced digital filter topologies...


I've made a solemn vow to never code in C.

Yes. C++ is lot better.

Funny! I write apps that run in, typically, 4-6 kilobytes of eprom and
2K of ram, manage a few FPGAs and a VME or serial/ethernet interface,
run thousands of interrupts per second, and have guaranteed response
times in the 100 usec sort of range, 100% of the time. And never
crash.



But comments don't explain
code, comments explain what code is for and what it does. Your filter
is just a heap of code. I have no idea what it's response is like, and
would have to analyze or simulate it to determine that.
So, what is its frequency response?

Here:

1/64
H(Z) = (---------------) ^ 4
63
1 - --- Z^-1
64



So, what is its frequency response?

John


.

Relevant Pages

  • Re: Free download spectral analyser.
    ... suite for measuring speaker response in-room. ... and the filter I built is an opamp with bridged RC T filter in the NFB ... Si I have 33 rest F for the whole audio band and I find it ... many speakers I test after working on them have large unwanted response ...
    (rec.audio.tubes)
  • Re: Free download spectral analyser.
    ... suite for measuring speaker response in-room. ... that will be good for most of the audio programs and tests (good S/N, IMD, ... and the filter I built is an opamp with bridged RC T filter in the NFB ... But to facilitate the measuring process, ...
    (rec.audio.tubes)
  • Re: Cassini: where are colors and detail?
    ... While one filter response may be dropping as you change ... Algorithms in consumer cameras for interpreting Bayer sensors also go ... have to do spectrometry using a Bayer filtered CCD as the sensor. ...
    (sci.astro.amateur)
  • Re: Basic info needed regarding filters (FIR)
    ... advanced digital filter topologies... ... run thousands of interrupts per second, and have guaranteed response ... flag to let the main loop know that a command string is ready, ... Even if you prefer assembler, you would benefit from learning C. ...
    (sci.electronics.design)
  • Re: Cassini: where are colors and detail?
    ... While one filter response may be dropping as you change ... > monochromatic light with classic Bayer filter arrays. ... You confuse cheap consumer digital camera problems with bayer sensor ...
    (sci.astro.amateur)