Presentation and some questions.

["Víctor E."]

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Hi guys, I'm new to comedi and to this list, my name is Víctor, I'm
working on my PFC for USAL universuty in Salamanca, Spain, and I've
some questions related to comedi.

Here are the questions, How comedi manages multiple asynchronous
adquisition? I mean, say that for example I have a NI-6221 board with
multiple subdevices that can made command adquisition, is comedi
capable of working with more than one subdevice at the same time? If
so how can I do it? Can I get a diferent file descriptor for each
writable/readable subdevice?

To get familiar with comedi, I also worked on a small project for
CUSLVI (Concurso Universitario de Software Libre VI) called Freeacq, I
did some code for listing devices and subdevices, and for doing some
tests (Still not finished) and a small acquisition demo using async
commands , the plan is to create a graphical/console application[s]
that can deal with acquisition devices using comedi. Also I modified a
sysrescuecd iso image including comedilib and the comedi drivers with
a 32 and 64 bit kernel, that maybe can be usefull for some users of
this list.

The code and the iso can be found here:
https://forja.rediris.es/projects/cusl6-freeacq/
In this link I have a blog (In spanish) related with Freeacq:
https://freeacq.wordpress.com


Thanks for your support, and sorry my typos.
- --
Víctor Enríquez
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[Ian Abbott]

Hi Victor,

On 2012-05-11 13:28, "Víctor E." wrote:
> Hi guys, I'm new to comedi and to this list, my name is Víctor, I'm
> working on my PFC for USAL universuty in Salamanca, Spain, and I've
> some questions related to comedi.
>
> Here are the questions, How comedi manages multiple asynchronous
> adquisition? I mean, say that for example I have a NI-6221 board with
> multiple subdevices that can made command adquisition, is comedi
> capable of working with more than one subdevice at the same time? If
> so how can I do it? Can I get a diferent file descriptor for each
> writable/readable subdevice?

Yes, but you have to open the other descriptors using different filenames.

The main file /dev/comedi0 (or whatever number) only lets you set up
asynchronous acquisitions on the default 'read' or default 'write'
subdevice. But there are subdevice-specific files, e.g.
/dev/comedi0_subd0, /dev/comedi0_subd1, etc., one for each subdevice
that supports asynchronous acquisition.

Some devices may have limited resources (such as shared timers) that
prevent multiple commands being set up at once.

> To get familiar with comedi, I also worked on a small project for
> CUSLVI (Concurso Universitario de Software Libre VI) called Freeacq, I
> did some code for listing devices and subdevices, and for doing some
> tests (Still not finished) and a small acquisition demo using async
> commands , the plan is to create a graphical/console application[s]
> that can deal with acquisition devices using comedi. Also I modified a
> sysrescuecd iso image including comedilib and the comedi drivers with
> a 32 and 64 bit kernel, that maybe can be usefull for some users of
> this list.
>
> The code and the iso can be found here:
> https://forja.rediris.es/projects/cusl6-freeacq/
> In this link I have a blog (In spanish) related with Freeacq:
> https://freeacq.wordpress.com

When it's finished (or at least usable), send a reminder so we can add a
link to the Comedi Applications page:

http://www.comedi.org/applications.html

--
-=( Ian Abbott @ MEV Ltd. E-mail: <abb...@mev.co.uk> )=-
-=( Tel: +44 (0)161 477 1898 FAX: +44 (0)161 718 3587 )=-

["Víctor E."]

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On 05/11/2012 03:06 PM, Ian Abbott wrote:
> Hi Victor,
>

> On 2012-05-11 13:28, "V�ctor E." wrote:
>> Hi guys, I'm new to comedi and to this list, my name is V�ctor,

Great, thanks! , I'll let you know about it.

- --
V�ctor Enr�quez

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[Bernd Porr]

I've completely forgotten about this. I was wondering how comedi2py can
work together with the comedi python API, for example using comedi2py to
record/plot sensor data and then being able to use the comedi python API
to send out a control signal via analogue out or PWM. Well, that solves
it obviously.

comedi2py uses now secretly /dev/comedi0_subd0 for the data acquisition
and the user can still do a c.comedi_open("dev/comedi0") within python
and use all the other features of the DAQ device.

http://www.linux-usb-daq.co.uk/software2/comedi2py/
Git and the tar ball are most up to date

/Bernd

Ian Abbott wrote:
> Hi Victor,
>

> On 2012-05-11 13:28, "V�ctor E." wrote:
>> Hi guys, I'm new to comedi and to this list, my name is V�ctor, I'm

www: http://www.linux-usb-daq.co.uk/
http://www.berndporr.me.uk/
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