Re: [Gumstix-users] Verdex SPI direct register example, OE

[Felipe B. C. <cav...@gm...>]

I also had some problems with the Verdex hanging while manipulating the UART
registers. I never got a chance to fix the problem, so I moved to a termios
approach.
However, any help on direct manipulation of the registers would be very
welcome as well.

As a side note, I always got junk when reading the registers as well. Any
clues?

Thanks for the help,
          -Felipe Brandão Cavalcanti
          LARA - Laboratory of Robotics and Automation
          Department of Electrical Engineering
          UnB - University of Brasília, Brazil
          http://www.lara.unb.br/

On Fri, Jun 12, 2009 at 2:03 AM, Scott Harris <sco...@gm...>wrote:

> I've gotten the SPI C code example here
> (http://docwiki.gumstix.org/Sample_code/C/SPI) to compile by making a
> simple bitbake recipe and I've loaded the resulting code onto my
> Verdex with ipkg , but the demo seems to hang. This is all the output
> I get:
>
>   ------------------------------------------
>   |               SPI Sample                |
>   ------------------------------------------
>   |   Direct Register Access SPI Sample     |
>   ------------------------------------------
>  -> Msg<- Initializing SPI port
> PXA270_GAFR0_L = 0xA48C0000
> PXA270_GAFR0_U = 0xA5254050
> PXA270_GAFR2_L = 0xA5254050
> Now Clocks enabled = 0x50c648
>  -> Msg<- Result of SPI Init = 1
>  -> Msg<- Sending test characters....
>
> and then program hangs here.
>
> I was expecting to see some more output. Once I got that working, I
> was going to hook up my logic analyzer to see if the SPI ouput was
> counting upwards.
>
> I'm trying to to interface to some DAC and ADC chips using the Verdex
> as the SPI master and a couple of GPIO pins as chip select. Is there
> an easier way to select a CS line and push a word out over SPI?
>
> I need to send only  one word at a high data rate to each chip, but
> the update rate I'm shooting for may only be 20-100 kHz. The
> application is real-time control with  the verdex. Since I'm not
> moving large amounts of data around, I was hoping that the register
> access approach would be sufficient.
>
> Any help would be appreciated.
>
> Thanks,
> -Scott
>
>
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