Only way to do this is to isolate the pins with a gate, enable the gate with a signal of your choice that you can turn on after your no power period is over
On 1/17/2016 9:31 AM, Davide Picchi wrote: > Did you fix this problem? > Because I m facing the same undesired behavior. > > Thanks > > Am Sonntag, 28. Juni 2015 22:04:07 UTC+2 schrieb andrew otis: > > Hey Everyone, > > I'm a n00b so please excuse me, but I have been trying to get my > BBB to boot with no power on P9-pin 11. > > Controlling them through /sys/class/export works fine but even if > I write a bash script to disable power, it still stays on for > about 5 seconds before my script runs to cut power. > > So, obviously I learned bash scripts are not the way to go here. > > Next, I tried exploring making the config changes in the boot > loader. I've modified beagle.c in u-boot source and commented out > this entire section: > > /* Set GPIO states before they are made outputs > writel(GPIO23 | GPIO10 | GPIO8 | GPIO2 | GPIO1, > &gpio6_base->setdataout); > writel(GPIO31 | GPIO29 | GPIO28 | GPIO22 | GPIO21 | > GPIO15 | GPIO14 | GPIO13 | GPIO12, > &gpio5_base->setdataout); */ > > /* Configure GPIOs to output > writel(~(GPIO23 | GPIO10 | GPIO8 | GPIO2 | GPIO1), > &gpio6_base->oe); > writel(~(GPIO31 | GPIO29 | GPIO28 | GPIO22 | GPIO21 | > GPIO15 | GPIO14 | GPIO13 | GPIO12), > &gpio5_base->oe); */ > > Recompiled, put MLO and u-boot.img in my /boot/uboot path but it > still doesn't seem to work. > > Again, I apologize for the n00bness, but would someone that has > experience doing this kind of thing be able to at least point me > in the right direction? > > are there other methods I can use in this $gpio5_base? > > End goal is to be able to hook up my multimeter to pin 11 on P9, > boot the device and never see voltage, until I want it (I got that > part down) > > -- > 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 > <mailto:beagleboard+unsubscr...@googlegroups.com>. > 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.
