Re: [Discuss-gnuradio] Developing for different A to D's

[Alan Gray]

> > I was just wondering how many changes (if any) need to be made to the base
> > code when using an A to D converter other than the PCI-DAS4020. I'm 
> working
> > on implementing an SDR system for my final year telecommunications
> > engineering thesis, and my university has supplied me with an ICS-645 card
> > (http://www.ics-ltd.com/product_catalog/ics_645.html) which has specs that
> > seem comparable to the PCI-DAS4020.
>
> Looks like it should work, and their web site indicates that there is
> a Linux driver available.
>
> > So, how much difficulty can I expect to encounter in:
> > a) adapting the code to work with the above card
>
> This shouldn't be much of a problem.  You'll need to look at their
> linux driver and the interface it exports.  If it's a conventional
> read/write/ioctl kind of interface, you may even be able to use the
> existing VrFileSource as the interface to the board after you've
> configured it appropriately using what ever ioctl's they provide.
>
> Worst case, you build a new module, say GrICS645Source, that produces
> N streams of shorts as its output, depending on how many A/Ds you've
> enabled.  This shouldn't be more than a few of pages of code, most of
> which will be very similar to the existing VrFileSource.

Thanks for your help Eric, I've finally got a system up and running to 
start work on my project (still awaiting the arrival of my SMP machine and 
tuner though, seems it takes a lot of time to get anything much done around 
here). I've acquired a second A/D card, the Adlink PCI-9812 
(http://www.adlinktech.com/products/DataAcquisition/PCI-981210.htm) which 
seems a little better suited to a GNU radio application, and thus I'm going 
to try to adapt the code to suit it first, and return to the ICS-645 at a 
later date.

I wonder if someone could expand a little on the data flow in the program 
and the format of data required, a "stream of shorts" was mentioned, but 
I'm a little shady on how that stream is implemented, stored and processed. 
The PCI-9812 comes with a rather extensive set of libraries which provide 
functionality for double-buffering and the like, so I can easily read in 
values to file, however I'm unsure as to how these can be applied to 
processing data in real time. Basically I think I'm having trouble 
understanding what modules like VrSource, VrFileSource and GrMC4020Source 
are doing, so if someone could explain these a bit or point me towards any 
resources which could give me a good idea of the functionality it would be 
most appreciated.

For some reason I can see a lot of coding in my near future
Thanks
Alan