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Thank you for the follow-up, Luis. If I understand you correctly,
does the disis_spi therefore work for at least 16 channels (via
opening 2 devices, 8 channels each) or it does not work at all?<br>
<br>
disis_spi has its own implementation of accessing spidevs, and
(AFAIR) it should not have any limitations as far as how many
devices can be opened at once (obviously, you will need one instance
per device). Perhaps the limitation you speak of is
hardware-specific?<br>
<br>
Best,<br>
<br>
Ico<br>
<br>
<div class="moz-cite-prefix">On 7/9/2015 3:42 AM, Luis Gerardo Angel
S. wrote:<br>
</div>
<blockquote cite="mid:1436406174.2201.0@smtp.gmail.com" type="cite">
Hi
<div><br>
</div>
<div>I probe the program, you were right you can specify the
device and it just work(attached example).</div>
<div>The controller have 3 chip selectors for the SPI (three
slaves), although you can only connect two devices according to
this: <a moz-do-not-send="true" href="http://elinux.org/RPi_SPI">http://elinux.org/RPi_SPI</a>.
You can confirm it with "ls /dev" command, there are only two
SPI devices.</div>
<div>I read in some forum (can't remember which ones) this is due
to how the library was written leaving out the third chip
selector.</div>
<div><br>
</div>
<div> At the present time the only way to connect more SPI devices
is: write your own SPI library (maybe with wiringPi) and use the
GPIO's general purpose(pardon the redundancy) pins like
selectors. It would be nice we can use the third selector with
another "/dev/spidev0.2" in that way the external does not have
to be modified and 24 analog inputs would be very good.</div>
<div><br>
</div>
<div>Luis G</div>
<div><br>
On mié, jul 8, 2015 at 3:49 , Ivica Ico Bukvic
<a class="moz-txt-link-rfc2396E" href="mailto:ico@vt.edu"><ico@vt.edu></a> wrote:<br>
<blockquote type="cite">
<div class="plaintext" style="white-space: pre-wrap;">Hi Luis,
I am not 100% sure but if I recall correctly, you can
specify which device you wish to open, so as long as each
device is assigned a different /dev node, this should work
just fine. I would appreciate it if you would please report
your results and let us know. Alternately, there are larger
D/A converters that provide you with more inputs, but will
also require a customized version of disis_spi.
Hope this helps!
Best,
Ico
On 7/7/2015 11:41 PM, Luis G Angel wrote:
<blockquote>Hi list
I want to use two MCP3008 in order to connect 16 analog
inputs to the Pi2, so my question is if the [disis_spi] is
capable to manage 2 slaves.
If it is, how it should be the patch to manage that.
Thanks for any idea
Luis G
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href="http://disis.music.vt.edu/listinfo/l2ork-dev">http://disis.music.vt.edu/listinfo/l2ork-dev</a>
</blockquote>
<div>-- </div>
Ivica Ico Bukvic, D.M.A.
Associate Professor
Computer Music
ICAT Senior Fellow
Director -- DISIS, L2Ork
Virginia Tech
School of Performing Arts – 0141
Blacksburg, VA 24061
(540) 231-6139
<a class="moz-txt-link-abbreviated" href="mailto:ico@vt.edu">ico@vt.edu</a>
<a moz-do-not-send="true"
href="http://www.performingarts.vt.edu">www.performingarts.vt.edu</a>
disis.icat.vt.edu
l2ork.icat.vt.edu
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L2Ork-dev mailing list
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href="http://disis.music.vt.edu/listinfo/l2ork-dev">http://disis.music.vt.edu/listinfo/l2ork-dev</a></div>
</blockquote>
</div>
</blockquote>
<br>
<pre class="moz-signature" cols="72">--
Ivica Ico Bukvic, D.M.A.
Associate Professor
Computer Music
ICAT Senior Fellow
Director -- DISIS, L2Ork
Virginia Tech
School of Performing Arts – 0141
Blacksburg, VA 24061
(540) 231-6139
<a class="moz-txt-link-abbreviated" href="mailto:ico@vt.edu">ico@vt.edu</a>
<a class="moz-txt-link-abbreviated" href="http://www.performingarts.vt.edu">www.performingarts.vt.edu</a>
disis.icat.vt.edu
l2ork.icat.vt.edu</pre>
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