disapointed with beaglebone

I’m very disappointed with the running of the beaglebone.

I’m not sure if this bad running is due to the Qt, the angstrom…but I have develop a program in Qt wich needs a (more or less) exact hundredth to read a inputs using the i2c-3 and the hundredths are very unstable. I put the oscilloscope and I lose signals.
I program the Qt hundreth as a: start(QThread::HighestPriority)
and anyway the signals appears every 2 or 3 hundreths.

Anyone knows how can I solved this problem?
thanks very much

(more or less) exact hundredth to read a inputs
expand what this means?
what are you reading on i2c?

— On Thu, 7/26/12, Rai32 ramon.benavent@gmail.com wrote:


> From: Rai32 ramon.benavent@gmail.com
> Subject: [beagleboard] disapointed with beaglebone
> To: beagleboard@googlegroups.com
> Date: Thursday, July 26, 2012, 6:33 AM
>
> I’m very disappointed with the running of the beaglebone.
>
> I’m not sure if this bad running is due to the Qt, the angstrom…but I have develop a program in Qt wich needs a (more or less) exact hundredth to read a inputs using the i2c-3 and the hundredths are very unstable. I put the oscilloscope and I lose signals.
> I program the Qt hundreth as a: start(QThread::HighestPriority)
> and anyway the signals appears every 2 or 3 hundreths.
>
> Anyone knows how can I solved this problem?
> thanks very much
>
> – To join: http://beagleboard.org/discuss
> To unsubscribe from this group, send email to:
> beagleboard+unsubscribe@googlegroups.com
> Frequently asked questions: http://beagleboard.org/faq

|

Using qt for real time processing? Very funny!

May be funny, but do you know any way??
I’m trying to include a C program:

#include <stdio.h>
#include <signal.h>
#include <sys/time.h>

typedef void (*sighandler_t)(int);

foo(int theint)
{
	printf("I just got the SIGALRM signal\n");
}

main()
{
	struct timeval my_value={1,0};
	struct timeval my_interval={1,0};
	struct itimerval my_timer={my_interval,my_value};
	setitimer(ITIMER_REAL, &my_timer, 0);
	
	int i;
	signal(SIGALRM, (sighandler_t) foo);
	for( ; ; )
		i=5;
}

in qt to get a “interrupt” time system from the system, but I’m having troubles introducing this king of function in qt.
This funtions only implements a static function, and I can’t tell any qt object from within.
Any help?

2012/7/27 Maxim Podbereznyy <lisarden@gmail.com>

I managed to get 2 hundredths (much more accurate than the beaglebone) in an Arm S3C6410 of Samsung using the Qt simple code.
Anyway I will investigate other options.
thanks.

2012/7/27 Ramon Benavent <ramon.benavent@gmail.com>

yup like asking why windows isnt realtime

It was only an example, I hoped to get a “signal time clock” with highest priority thread of qt. I need a time base to poolling my functions in the program: to count hundreths, seconds, to read input states, set outputs (with a i2c 8 channels I/O ). If I can get this precission with qt, I’ll try to get an interrupt from kernel, but I’not sure to do that in rigth way. So if anyone have been the same problem or know something about this subject I’ll be grateful. Thanks in advance.

You might be interested to read the following blog post about our
attempts to generate precise PWMs with GPIO using Xenomai:
http://veter-project.blogspot.de/2012/04/precise-pwms-with-gpio-using-xenomai.html