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Re: [Xylo-SDR] Saxo



Chris, 

I don't think that a generic USB Audio device driver will do what we want.  
Apart from full duplex audio our USB link will take  PTT, CW keyer, 
Forward/Reverse power, SWR, 200MHz frequency error, LPF filter settings, BPF 
filter settings, DDS/NCO frequency etc etc. 

I have zero knowledge of PC drivers so I may be completely wrong about this. 

Phil...VK6APH 






Quoting "Christopher T. Day" <CTDay@lbl.gov>:

> I would like to reemphasize a point in my original comment and which
> Edison alluded to: If out USB device follows the USB Audio Device spec,
> then the required driver is GENERIC, i.e., it is written and supplied by
> the OS supplier, not us. [Emphasis mine and likely wrong since I haven't
> really read the spec yet, but it sounds like this is the way it should
> be.] Like wise for at least some of the other USB Device Classes. As
> evidence, as faar as I can tell, I'm running my SDR-1000 with a Sound
> Blaster MP3+ USB device and using the generic MS USB Audio Device
> driver, not the one from CreativeLabs. 
> 
> 
> Chris
> 
> 
> -----Original Message-----
> From: Edson Pereira [mailto:ewp_jp@ybb.ne.jp] 
> Sent: Saturday, January 21, 2006 9:32 PM
> To: Xylo-SDR Discussion
> Subject: Re: [Xylo-SDR] Saxo
> 
> 
> Hi Phil,
> 
> Thanks for the comments.
> 
> In order to avoid the problems caused by non-synchronized clocks, I am
> considering resampling the PC soundcard audio input and output (which
> will be running at a lower sampling rate) using a fractional FIR
> decimator and interpolator. I still need to look closer at the problem
> and see how easy or complex it is.
> 
> One reason I have purchased the Saxo is that I could use 2 ADs and 2 DAs
> and avoid all the problems you have mentioned. However, VHDL or Verilog
> are obstacles for me at the moment. Verilog looks a bit familiar due to
> its C-like syntax, but I need to dedicate some time (the most scarce
> resource at the moment) to learn it enough to be able to do something
> useful.
> 
> 73,
> 
> -- Edson
> 
> 
> Phil Harman wrote:
> 
> >Hi Edson,
> >
> >Your project sounds very interesting. Just one thing to be aware of.  
> >If you use an external A/D converter as input and a sound card for 
> >output then unless the crystal clocks are exactly the same frequency 
> >you end up getting breaks in the audio due to the beat between the two
> clocks.
> >
> >For example, using my Wolfson A/D as the source and my Delta 44 to play
> 
> >back all is well for about  a minute - the clocks have then drifted 
> >apart enough to cause a frequent ticking sound.
> >
> >This is not a problem for our project since all the A/D's and D/A's all
> 
> >run off the same master clock.
> >
> >This was the reason that until the dual sound card Delta 44 we did not 
> >have VOX on the SDR1000.
> >
> >There may be a way round this problem - if you find one be sure to let 
> >us know since using the internal PC for playback would be a nice
> option!
> >
> >73's  Phil... VK6APH
> >]
> >----- Original Message -----
> >From: "Edson Pereira" <ewp_jp@ybb.ne.jp>
> >To: "Xylo-SDR Discussion" <xylo-sdr@lists.ae5k.us>
> >Sent: Sunday, January 22, 2006 12:41 PM
> >Subject: Re: [Xylo-SDR] Saxo
> >
> >
> >  
> >
> >>Hi Chris and Phil,
> >>
> >>I would like to implement a USB Audio device exactly in order to avoid
> 
> >>having to write any device driver software on the PC side. The USB 
> >>Audio Class device specification should not be too complex to 
> >>implement in the
> >>FX2 (I hope). I have recently acquired the TUSB3200 chip, which is an 
> >>embedded USB Audio stream controller. It does however only support USB
> 
> >>full speed (12 Mbps), which will limit the sampling rate to 96 kHz 
> >>half-duplex. This is ok for me at the moment since I do intend to use 
> >>my laptop internal soundcard for mic and speaker.
> >>
> >>I wish the FX2 had an I2S interface!
> >>
> >>In my little project, I would like to focus on the implementation of a
> >>96 kHz half-duplex USB soundcard (USB Audio specification)  and a 
> >>generic parallel I/O port (USB HID specification). Everything in a 
> >>single little board. Anyone on the list interested in joining efforts?
> >>
> >>73,
> >>
> >>-- Edson
> >>
> >>Phil Harman wrote:
> >>
> >>    
> >>
> >>>Hi Chris,
> >>>
> >>>I have a prototype full duplex USB2 sound card going based on the 
> >>>Wolfson A/D chip and Xylo/Saxo FPGA board.  At the moment it runs at 
> >>>48k and 16 bits but the chip can do 192k and 24 bit. Need to walk 
> >>>first but the pace is picking up!
> >>>
> >>>Writing a generic USB Audio Device driver is way beyond me. Our aim 
> >>>is to keep the interface to the A/D converter inside the PC as simple
> 
> >>>as possible so I don't see the need for a 'real' device driver - we 
> >>>are not trying to compete with the D44 for example.
> >>>
> >>>73's Phil...VK6APH
> >>>
> >>>Phil....VK6APH
> >>>
> >>>
> >>>
> >>>    ----- Original Message -----
> >>>    *From:* Christopher T. Day <mailto:CTDay@lbl.gov>
> >>>    *To:* xylo-sdr@lists.ae5k.us <mailto:xylo-sdr@lists.ae5k.us>
> >>>    *Sent:* Sunday, January 22, 2006 10:29 AM
> >>>    *Subject:* [Xylo-SDR] Saxo
> >>>
> >>>    What few useful thoughs I've had so far on the subject agree with
> >>>    yours - if possible [does the USB Audio Device spec go as far as
> >>>    24-bit stereo, 96/192 ksamples/sec?], the USB-2 interface should
> >>>    be able to use a generic USB Audio Device driver => we don't have
> >>>    to supply/maintain one for any/all OS. But then, I know almost
> >>>    nothing yet,
> >>>
> >>>
> >>>    Chris - AE6VK
> >>>
> >>>      
> >>>
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> >>
> >>
> >>--
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> >>
> >>
> >>    
> >>
> >
> >
> >
> >  
> >
> 
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