Well, I've tried upgrading the origianl 1.0 Amp power supply with a 2.5 Amp
power supply... It didn't solved the issue... And since the new one was more
thand the double of the previous one, I'm pretty sure I'm well over the "edge"
:P
As for the coding style, I'm well aware there's a much better way, but since it
isn't really an issue in our small project, and most of all, much simpler,
there aren't any reason for me to upgrade. And mostly, since I'm a student in
computer engennering, I'm kinda lacking this kind of knowledge too. And it's my
theacher that has been doing it this way in the beggining!
I've also looked at the errata on this specific CPU, but it's revision
specific, and both (32 & 64 mb) card have the same E2 revision, so they would
both be bothered by the SPI errata!
I'm still out of ideas!
--- In "Breton M. Saunders" <>
wrote:
>
> Check for power supply problems. Although unlikely, you could be
> running your power supply on the edge - problems wouldn't appear on the
> 32Mb version, but the 64Mb version with slightly higher power
> requirements could just push you over the edge.
>
> Otherwise, there shouldn't be any differences between the 64/32 mib
> versions with regard to SPI connected devices.
>
> One question though: You have written a kernel driver to talk to the the
> SPI display device right? This idea that writing to hardware using
> user-mode code is completely brain-dead - you have no control over
> timing problems, interrupts, or for that matter any access to the
> features that the linux kernel provides you for device driver management.
>
> -Brett
>
> jeremfg wrote:
> > Hi!
> >
> > We are currently trying to use the serial Digilent PmodCLS LCD with the SPI
> > bus on a TS-7400 64mb version. The PmodCLS is a serial LCD including it's
> > own microchip, so we only need to send ASCII characters on the SPI bus, and
> > everything else is handled by the LCD.
> >
> > PmodCLS ->
> > http://www.digilentinc.com/Products/Detail.cfm?NavPath=2,401,473&Prod=PMOD-CLS
> >
> > Currently, it's working really fine with the 32mb version of the card, we
> > can write on the CPU's registers of the SPI bus, and everything shows up
> > fine on the LCD...
> >
> > However, as soon as we move to the 64mb version of the card, there is some
> > messup... Even though the card seems indentical, same CPU and everything
> > else seems identical except for the extra memory chip, it doesn't work
> > well...
> >
> > I can assure you that the issue is hardware related... We've also tryed
> > using the same SD card with the exact same OS on the 32-bit and 64-bit
> > version...
> >
> > half the times, it simply does nothing on the LCD, the other half is
> > splitted in two... some time writing the last character of the string I was
> > sending, or in the second case, the last character of the last attempt
> > followed by the first character of the current attempt....
> >
> > Never more than two characters, and it seems really slow in execution,
> > compared to the 32mb version. Looking on an oscilloscope, we can clearly
> > see that the LCD obey what it is sent... Only one, two or zero characters
> > are sent, electrically, to the LCD so it isn't the issue!
> >
> > So, Is there any difference at all between the 32Mb version and the 64Mb
> > version that isn't visible to the naked eye?
> >
> > Or does anyone have an hypothesis on what the problem could be?
> >
> > All I know, is that I base my C code on the temp_sensor example, and
> > followed the documentation of the CPU thoroughly for initialisation and
> > operation
> >
> > Any help would be greatly welcome!
> >
> >
> >
> > ------------------------------------
> >
> > Yahoo! Groups Links
> >
> >
> >
>
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