Interrupt can't be used traditionally from userspace. interrupts used
traditionally are kernelspace only. However . . . there are tricks to
getting around, but performance will suffer. Which leaves us back at square
1

On Tue, Aug 2, 2016 at 4:31 PM, evilwulfie <[email protected]> wrote:

> Or use a gpio pin that generates an interrupt, mask interrupts do your
> data retrieval re enable interrupts.
>
> you are asking for this kind of an issue when polling.
>
> On 8/2/2016 3:36 PM, William Hermans wrote:
>
> Yes, I have 2-3 suggestions where the first suggestion may not work, but
> are worth attempting.
>
>
>    - Upgrade to an RT kernel.
>    - Use /dev/mem/ + mmap()
>    - Bit bang via a PRU
>    - Or write a kernel driver that does all this from kernelspace, but
>    writes data to a file userspace hass access to.
>
>
>
> On Tue, Aug 2, 2016 at 3:17 PM, Kirk <[email protected]> wrote:
>
>> All,
>>
>> I'm working on a Beaglebone Black project using a MEMS accelerometer
>> chip, the ADXL312.
>>
>> The accelerometer has a pin which goes active each time a new data sample
>> is available to be read.
>> It runs at 3200 Hz.  (about 1/3 of a ms per sample)
>>
>> The pin is connected to a GPIO input and I've written code to monitor
>> this pin and grab the data each time.
>> The sampling normally runs for several seconds continuously.
>>
>> The problem is, every once in a while Linux gets busy and apparently
>> interrupts my code and I miss samples.
>> (an overrun bit lets me know this is happening)
>>
>>
>> I'm looking for ideas on how to improve this so data samples are not
>> missed.
>>
>> Any ideas?
>>
>> Kirk
>>
>> --
>> For more options, visit http://beagleboard.org/discuss
>> ---
>> You received this message because you are subscribed to the Google Groups
>> "BeagleBoard" group.
>> To unsubscribe from this group and stop receiving emails from it, send an
>> email to [email protected].
>> To view this discussion on the web visit
>> https://groups.google.com/d/msgid/beagleboard/564cb216-36a0-4528-874c-f89053d61876%40googlegroups.com
>> <https://groups.google.com/d/msgid/beagleboard/564cb216-36a0-4528-874c-f89053d61876%40googlegroups.com?utm_medium=email&utm_source=footer>
>> .
>> For more options, visit https://groups.google.com/d/optout.
>>
>
> --
> For more options, visit http://beagleboard.org/discuss
> ---
> You received this message because you are subscribed to the Google Groups
> "BeagleBoard" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to [email protected].
> To view this discussion on the web visit
> https://groups.google.com/d/msgid/beagleboard/CALHSORpCjghcxUpi05Wxx8ak-SF22tsLQk5WfUSQaJrsB-FJ_Q%40mail.gmail.com
> <https://groups.google.com/d/msgid/beagleboard/CALHSORpCjghcxUpi05Wxx8ak-SF22tsLQk5WfUSQaJrsB-FJ_Q%40mail.gmail.com?utm_medium=email&utm_source=footer>
> .
> For more options, visit https://groups.google.com/d/optout.
>
>
> --
> For more options, visit http://beagleboard.org/discuss
> ---
> You received this message because you are subscribed to the Google Groups
> "BeagleBoard" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to [email protected].
> To view this discussion on the web visit
> https://groups.google.com/d/msgid/beagleboard/276e93fe-e0fc-70b0-fa8a-98283c4a1730%40gmail.com
> <https://groups.google.com/d/msgid/beagleboard/276e93fe-e0fc-70b0-fa8a-98283c4a1730%40gmail.com?utm_medium=email&utm_source=footer>
> .
>
> For more options, visit https://groups.google.com/d/optout.
>

-- 
For more options, visit http://beagleboard.org/discuss
--- 
You received this message because you are subscribed to the Google Groups 
"BeagleBoard" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to [email protected].
To view this discussion on the web visit 
https://groups.google.com/d/msgid/beagleboard/CALHSORo5%3DB8EGPeEQZhoiiH9QwusJoqu-%2BXvT4PYgAQozWq4-A%40mail.gmail.com.
For more options, visit https://groups.google.com/d/optout.

Reply via email to