As a side note, you can also emulate open drain. Set the pin output state to 0, then enable/disable the output driver. And, for performance, writing to the gpio registers rather than doing file operations with sysfs is > 30 times faster.
And, pin muxing (pullups/down and input receiver enable for reading pin state) is separate from the gpio operations (output driver enable/disable, reading physical pin state, setting output driver level). On Wednesday, August 27, 2014 12:02:11 PM UTC-7, Gerald wrote: > > But, you have to watch the pullups and pull downs when you do that. > > Gerald > > > > On Tue, Aug 26, 2014 at 8:20 PM, John Syn <john...@gmail.com <javascript:> > > wrote: > >> >> From: Gerald Coley <ger...@beagleboard.org <javascript:>> >> Reply-To: "beagl...@googlegroups.com <javascript:>" < >> beagl...@googlegroups.com <javascript:>> >> Date: Tuesday, August 26, 2014 at 1:06 PM >> To: "beagl...@googlegroups.com <javascript:>" <beagl...@googlegroups.com >> <javascript:>> >> Subject: Re: [beagleboard] Tri-state GPIOs? >> >> No. >> >> You can emulate tristate by changing GPIO outputs to GPIO inputs. >> >> Regards, >> John >> >> >> Gerald >> >> >> >> On Tue, Aug 26, 2014 at 4:36 AM, <david.b...@gmail.com <javascript:>> >> wrote: >> >>> Hey Guys >>> >>> Has the Beaglebone black *tri-state gpios*? >>> >>> When yes, how can I set up them? >>> >>> Thanks >>> >>> -- >>> 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 beagleboard...@googlegroups.com <javascript:>. >>> 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 beagleboard...@googlegroups.com <javascript:>. >> 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 beagleboard...@googlegroups.com <javascript:>. >> 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 beagleboard+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
