From: Tony DiCola <[email protected]> Reply-To: <[email protected]> Date: Wednesday, June 4, 2014 at 8:29 AM To: <[email protected]> Subject: Re: [beagleboard] Beaglebone Black libraries for GPIO access in C/C++?
> Thanks for the replies everyone--looks like some nice libraries to check out. > > Regarding memory mapped GPIO, check out this nice blog post for more info: > http://vabi-robotics.blogspot.com/2013/10/register-access-to-gpios-of-beaglebo > ne.html You can effectively map the GPIO registers to a process' memory space > and directly access them so there's no overhead of making the system calls to > read, write, etc. the sysfs-based GPIO. > > I actually just tried out a couple quick tests and saw toggling a pin high and > low in a tight loop with sysfs is pretty slow, only a few hunded khz. However > using memory mapped GPIO registers it's much, much faster. I'm seeing around > 2.8 mhz toggling a pin with this approach. Now neither approach is > technically going to ever give you a real time guarantee of course, but it's > nice to have the ability to read and write GPIO fairly quickly in some cases > with memory mapped GPIO. The downside is you cannot support GPIO interrupts. Regards, John > > > On Wed, Jun 4, 2014 at 5:00 AM, Micka <[email protected]> wrote: >> William Hermans, how did you controlled the GPIO ? >> >> The only way that I know is with : >>> >>> /sys/class/gpio/gpio%d/value >> >> but you talk about mmap ? How did you use it with this >> /sys/class/gpio/gpio%d/value ? >> >> Thx you, >> >> Micka, >> >> >> >> >> On Tue, Jun 3, 2014 at 11:57 PM, William Hermans <[email protected]> wrote: >>> sysfs, and mmap. I've seen mention of both on the web ( including for the BB >>> white ). >>> >>>> wiringPi >>> >>> Whats this ? The Arduino IDE for the rPI ? Nothing like this exists for the >>> BBB that I am aware of. >>> >>> >>> On Tue, Jun 3, 2014 at 2:45 PM, Jacek Radzikowski >>> <[email protected]> wrote: >>>> <shameless plug> >>>> https://github.com/piranha32/IOoo >>>> </shameless plug> >>>> >>>> j. >>>> >>>> >>>> On Tue, Jun 3, 2014 at 5:42 PM, Tony DiCola <[email protected]> wrote: >>>>> > Sorry if this is a common question, but I've searched around the web and >>>>> the >>>>> > forum here and am curious are there any somewhat mature or popular >>>>> libraries >>>>> > for simple digital GPIO access on the Beaglebone Black in C/C++? I'm >>>>> > curious if there's anything like wiringPi or similar for the BBB yet. >>>>> If >>>>> > not, are folks just rolling their own thing with access to sysfs or >>>>> mmap? >>>>> > >>>>> > -- >>>>> > 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] >>>>> <mailto:beagleboard%[email protected]> . >>>>> > For more options, visit https://groups.google.com/d/optout. >>>> >>>> >>>> >>>> -- >>>> Given a choice between two theories, take the one which is funnier >>>> >>>> -- >>>> 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] >>>> <mailto:beagleboard%[email protected]> . >>>> 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]. >>> 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 a topic in the Google >> Groups "BeagleBoard" group. >> To unsubscribe from this topic, visit >> https://groups.google.com/d/topic/beagleboard/Mef65w6PZ7s/unsubscribe. >> To unsubscribe from this group and all its topics, send an email to >> [email protected]. >> 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]. > 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]. For more options, visit https://groups.google.com/d/optout.
