i'm new to the system, and for a project i'm working on, i'm in need of a task
to wake up every 500usec to 1msec to monitor digital I/O lines on the TS7500
unit. There may be a need to read/write data on I2C devices as well at this
time. essentially a 1kHz to 2kHz sampling interval would best sum up the timing
requirements.
what is the best way to manage this on this unit. doing some tests i found that
having a task usleep(1000) to generate a 1msec wakeup didn't keep up. getting
closer to 1/4 second (usleep(250000)) seemed to create accurate 1/4 second
timing.
is there a better way of doing this on the TS7500?? is there a better task
delay function than usleep()??
can a user task configure a timer that fires off an interrupt to task at this
rate??
running a task that does nothing but I/O work generates obviously 99% cpu
utilization, but the console prompt, etc., appear to be quite responsive.
busybox "top" command reports overall CPU load in this situation as 34% which
makes me think that there's plenty of horsepower to do a 2kHz to 1kHz sampling
rate.
or will I need to implement a kernel module to manage this, as I would assume
kernel timing would be more accurate than userland delay timing??
any thoughts would be valuable.
-ig
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