Re: Problems with Pyramid-Display

Hi,

On 30.10.2012, at 07:28, Markus Dolze <[email protected]> wrote:

> On 29.10.2012 19:02, Manuel Dejonghe wrote:
>> Hi all,
>> I am currently encountering some problems with some Pyramid Displays that we got. The displayed text seldom makes sense and reacts to keypresses only very very late.
> 
> Which version of LCDproc to you use? Versions prior to 0.5.5 had some
> problems communicating with Pyramid displays.

Yes, version 0.5.5

> 
> Which OS are you using? On Linux there are known problems perhaps
> related to hi-resolution timers. Read
> http://lists.omnipotent.net/pipermail/lcdproc/2009-September/013089.html.

Thank you very much, that did the trick.

As far as I understand, every user of "LCDd -d pyramid" has to expect this problem, since kernel 2.6.21. I suppose that http://lcdproc.sourceforge.net/docs/current-user.html#pyramid-howto as well as the LCDd.conf [pyramid] sections would be where a heads up warning could be searched for and read.
Or is this a more general problem, rather than to be specific for the pyramid-display ?

Is there possibly another fix for this problem ? Disabling the highres timers brings us trouble with the internal clock of virtual machines.
Looking at the code of the pyramid driver (pylcd.c), I see things like "usleep(50);". That's microseconds. Could it be that the kernel WITH highres is actually able to do that, and the "old" code relies on the kernels behaviour beeing a little sloppy without highres ?

>> 
>> Is there somewhere some documentation about the protocol spoken to the display ? I'd love to tap that connection for debugging, or also to simulate either side of the communication.
> 
> Yes, there is. I am currently checking if I am allowed to redistribute it.

Thank you, I got an 8 pages "Pyramid Appliance Display USB-Version Telegrammbeschreibung" by now. The document does not have any information about copyright, license or distribution restrictions.

kind regards,
Manuel Dejonghe

******************************* 
PrimeKey Labs GmbH
Krantzstr. 7 (Halle 15)
52070 Aachen
Germany
********************************