Got it into broken state again. My notes were incorrect, I see 5V on the power button, and 0V on the reset button. Holding down power button for 8 seconds results in a blip on USR2, but no boot. I'm thinking it's got to be cape-based, and I'm holding a pin high that shouldn't be high until after boot. But I'm not using any of the EMMC pins or boot pins (or any P8 pins for that matter).
On Wednesday, December 2, 2015 at 3:31:17 PM UTC-8, Jonathan Ross wrote: > > I didn't test the 8 second holddown of the power button but I doubt it > would help, and unfortunately it's not a reproducible issue. I'll have to > wait for it to happen again. > From my notes, I was seeing zero volts on power, 5V on reset. > The zero volts on power was very weird. From the KL16 I'm "toggling" my > own effective power button that is a transistor between the power pin on > the header and ground. The KL16 pin was not driven high (I checked), so I > don't think it was the transistor on the cape that was pulling pwr to > ground on the BBB. And the physical button wasn't pressed in. It was as if > the pullup at the PMIC wasn't active, yet the power LED was on. Is that > possible? > Wish I hadn't pulled the 5V power to reset, then I could do more testing. > > On Wednesday, December 2, 2015 at 2:11:58 PM UTC-8, Gerald wrote: >> >> I would start with your cape design and try and rule that out first. >> >> The reset is an input pin read by the processor, not actually a HW power >> reset. If the SW is locked up, this could happen. >> >> If you hold the power button for a 8 seconds or more the board should >> power cycle. >> >> When it is in this state, what do the voltages read? >> >> Gerald >> >> >> On Wed, Dec 2, 2015 at 3:54 PM, Jonathan Ross <jon...@nephology.org> >> wrote: >> >>> Once in a blue moon one of my beaglebones will get into a state where it >>> has power (the power LED is lit), but it is not booted. Normally this would >>> be fine, just hit the power button to reset. But in this weird state the >>> power button does nothing. The reset button does nothing. >>> I checked the power and reset button pins on the header, the power was >>> low, the reset was high. >>> The only way to get the board out of this state was to pull the 5V power. >>> I'm using a KL16 on a cape to do a watchdog on the BB, and reboot it via >>> power and/or reset buttons on the header if the BB stops sending checkins >>> over uart. This has been working great, except for the rare case where the >>> board ends up in this state where the power and reset buttons are not >>> functioning. >>> Any ideas how the BB could get into this state, and if there's any other >>> way to force a reboot other than physically pulling the 5v power? >>> Thanks, >>> JR >>> >>> -- >>> 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. >>> For more options, visit https://groups.google.com/d/optout. >>> >> >> >> >> -- >> Gerald >> >> ger...@beagleboard.org >> http://beagleboard.org/ >> > -- 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.
