[Lf] programming for Windows

[Andre' Kesteloot]

Rik Strobbe wrote:

> I agree with Andy and Bill, I am using Delphi for programming under windows
> (ea. QRS) and accessing the PC soundcard is a real pain. The only driver I
> found working more or less satisfying is commercial and costs over 300 USD.
> Some freeware drivers I found were excellent tools to crash my PC.
> I have also my doubts about the accuracy and stability of the data
> aquistition with a soundcard.
> But the one BIG advantage is that is available in any multimedia PC and
> there are no additional cost and/or work for the users. So, although the PC
> soundcard may not be suitable for a 'top end' DSP system it is an easy way
> to get started with it.
>
> Regarding 8-bit vs. 16-bit ADC : main difference is the dynamic range that
> is (or should be) over 40dB better for a 16dB card. The 48dB dynamic range
> that a 8-bit ADC offers might be a bit less in some applications. But there
> are a number of cheap 12-bit ADCs with serial output that can be used, with
> a dynamic range of 72dB these might be very suitable. Using 115kB data
> transfer via the serial port sample rates up to 7.5kHz are possible.
>
> 73, Rik  ON7YD
>
> At 10:34 7/07/00 -0400, you wrote:
> >At 01:06 PM 7/7/00 +0100, Andy, G4JNT wrote:
> >
> >>Believe me, driving the Soundcard is by far the most complex part of
> >>doing any DSP work on a PC and puts off many software authors who want
> >>to concentrate on writing decent software than interfacing to Windows !
> >>It is so messy being forced to use Windows that I haven't even tried
> >>going this route.
> >
> >Well said!
> >
> >I have a version of CRUNCH that uses the SB16 sound card
> >instead of my usual 8-bit Sigma-Delta serial port interface.
> >I haven't decided whether to release it because I don't want to
> >hear a chorus of criticism from the Windows people.
> >
> >I know everyone wants Windows software because that's what they've
> >been programmed to want by Microsoft hype.  So far I have not found
> >any version of Windows that is capable of running this new program.
> >Why should I go to the trouble of making things compatible with
> >some glorified "etch-a-sketch" operating system when I have already
> >"upgraded" my computer to DOS? :-)
> >
> >Let the Windows people write their own software.
> >
> >Sound cards have other problems...  There seem to be a lot of different
> >versions out there.  And the sampling rate isn't very precise.  For
> >slow BPSK work where frequency and long-term timing accuracy are
> >important you pretty much have to customize each copy of the program by
> >calibrating against the specific soundcard it will be running on.
> >
> >I'm not willing to go to the trouble of supporting umpteen different
> >sound card configurations when I'm giving out free software.  Don't
> >expect me to play by your rules.
> >
> >>When time and other projects permit, I will be
> >>making an LF Rx to this design and writing my own software for display
> >>and filtering that will run on any old PC using DOS rather than having
> >>to use the latest Win 95 technology just to drive the A/D converter.
> >
> >Bravo!
> >
> >>In the past, using an 8 bit A/D based on a 16C71 PIC plus PC I have seen
> >>signals that are -20dB S/N in a 300Hz CW filter, using custom
> >>Spectrogram type software written in the Basic programming language.
> >
> >Similar results here.  When looking for weak signals in noise, I have
> >yet to find any significant difference between 16-bit sound card audio
> >and 8-bit audio from my S/D board coming in through a serial port.  There
> >is likely a narrow range of band conditions under which the sound
> >card's 16 bits would be marginally advantageous, though.  That's why
> >I'm playing with it.
> >
> >Bill VE2IQ
> >
> >
> >