Mesa 5i25/6i25 my own component: how to begin?
04 Nov 2015 00:24 #64712
by ArcEye
Replied by ArcEye on topic Mesa 5i25/6i25 my own component: how to begin?
I think your threads are simply too fast.
A Xenomai kernel is normally only used with a servo-thread and step generation hardware. It makes no sense to have a sampler running faster than the operating thread speed
and even on a software stepper rtai kernel with a base thread, you would normally run it on the servo-thread, which is typically 10x slower.
sampler has a full bit pin which tells you when the FIFO is full and an overruns pin which tells you how many times this has happened.
These can be used to tune the depth of the buffer and tell you if you are just collecting too many of them (thread too fast)
The realtime part of sampler outputs to a buffer and the userspace part reads the buffer and outputs as required, normally a file.
If you look at src/hal/components/sampler_usr.c you will see this at the top of the reading loop
This may give a clue as to the expected operating speed, that it will pause for 10 polls of the 'average' servo-thread if the FIFO is empty.
It is certainly not expecting 100,000 samples to be added to that FIFO in that 10ms
regards
A Xenomai kernel is normally only used with a servo-thread and step generation hardware. It makes no sense to have a sampler running faster than the operating thread speed
and even on a software stepper rtai kernel with a base thread, you would normally run it on the servo-thread, which is typically 10x slower.
sampler has a full bit pin which tells you when the FIFO is full and an overruns pin which tells you how many times this has happened.
These can be used to tune the depth of the buffer and tell you if you are just collecting too many of them (thread too fast)
The realtime part of sampler outputs to a buffer and the userspace part reads the buffer and outputs as required, normally a file.
If you look at src/hal/components/sampler_usr.c you will see this at the top of the reading loop
while ( samples != 0 ) {
while ( atomic_load_explicit(&fifo->in, memory_order_acquire) == fifo->out ) {
/* fifo empty, sleep for 10mS */
delay.tv_sec = 0;
delay.tv_nsec = 10000000;
nanosleep(&delay,NULL);
}This may give a clue as to the expected operating speed, that it will pause for 10 polls of the 'average' servo-thread if the FIFO is empty.
It is certainly not expecting 100,000 samples to be added to that FIFO in that 10ms
regards
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