On Thursday 18 April 2013, Gilles Chanteperdrix wrote:
On 04/18/2013 06:38 PM, Ross Williamson wrote:
Is this a bad idea from a RTlinux point of view or a style point of
view?
It is a bad idea from a very general point of view. gpiolib does two
things: - it ensures that no two drivers try
On 04/19/2013 11:44 AM, Paul wrote:
On Thursday 18 April 2013, Gilles Chanteperdrix wrote:
On 04/18/2013 06:38 PM, Ross Williamson wrote:
Is this a bad idea from a RTlinux point of view or a style point of
view?
It is a bad idea from a very general point of view. gpiolib does two
things: -
On 04/18/2013 01:12 AM, Ross Williamson wrote:
So I managed to get it working in kernel space - I'm not entirely sure what
I did to fix it - I did a full read/modify/write on the GPIO registers
That is not a good idea either. You should use the gpiolib interface.
--
Ross,
any reason not to use just userland memory mapped port I/O like with this
library: http://www.airspayce.com/mikem/bcm2835 ?
that worked fine for me with a userland RT thread, no drivers needed
- Michael
Am 17.04.2013 um 22:12 schrieb Ross Williamson rwilliam...@astro.caltech.edu:
I'm
Hi Michael,
I did manage to get the userland working great but I was hoping to get a
bit better latency hence the kernel module. I'll probably be ok with the
userland but it would be nice to get the kernel version working...
Cheers,
Ross
On Wed, Apr 17, 2013 at 1:59 PM, Michael Haberler
On 04/17/2013 10:59 PM, Michael Haberler wrote:
Ross,
any reason not to use just userland memory mapped port I/O like with this
library: http://www.airspayce.com/mikem/bcm2835 ?
that worked fine for me with a userland RT thread, no drivers needed
It is a bad idea to access GPIO
So I managed to get it working in kernel space - I'm not entirely sure what
I did to fix it - I did a full read/modify/write on the GPIO registers and
changed the gpio pointer to u8 but that's about it. Works ok at outputting
a 10khz square wave with about a few us latency but doesn't look that
Hi Ross,
I'm guessing that doesn't say much. Anyhow code is below - feel free to rip
it apart or tell me better ways of doing things.
You might be interested to take a look at the following article:
http://veter-project.blogspot.com/2012/04/precise-pwms-with-gpio-using-xenomai.html
