[L2Ork-dev] 2 SPI slaves in RbPi2

Luis Gerardo Angel S. luisgerardoangelpd at gmail.com
Thu Jul 9 01:42:54 UTC 2015


I probe the program, you were right you can specify the device and it 
just work(attached example).
The controller have 3 chip selectors for the SPI (three slaves), 
although you can only connect two devices according to this: 
http://elinux.org/RPi_SPI. You can confirm it with "ls /dev" command, 
there are only two SPI devices.
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.

 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.

Luis G

On mié, jul 8, 2015 at 3:49 , Ivica Ico Bukvic <ico at vt.edu> wrote:
> 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:
>> 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
>> _______________________________________________
>> L2Ork-dev mailing list
>> L2Ork-dev at disis.music.vt.edu
>> http://disis.music.vt.edu/listinfo/l2ork-dev
> --
> 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
> ico at vt.edu
> www.performingarts.vt.edu
> disis.icat.vt.edu
> l2ork.icat.vt.edu
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