Hello Graham, thanks for your feedback.
I tried running PocketBeagle from Vin/pin1 and it worked smoothly here for more than 13 hours. It was powered via 5V that came from a USB connector. But I was running a bare metal application with no Linux involved. So may be there is a bug rather in the Linux system you are using than in the hardware? I remember the PMIC of the BeagleBone could be accessed from software, watchdog with some illegal parameters would be a candidate too (OK, watchdog would not explain why the power pin has an influence...). With kind regards Mike On Saturday, December 9, 2017 at 6:11:39 AM UTC+1, Graham wrote: > > I have been unable to get a PocketBeagle to run for more than about 12 > hours without rebooting when powered from Vin (P1-pin1), using a trusted > power supply. > It usually reboots itself successfully, so in order to see it, run some > commands to turn off the blinking blue lights. If they come back on by > themselves, it has rebooted. > Or you can read the system logs. > > It works fine when powered from Vi (P1-pin7) which is the same as the Vusb > +5 Volt input/output. > It works fine when Vi and Vin are paralleled, but I am uncomfortable > paralleling power supplies, unless someone who really understands them says > it is OK. > > The docs indicate that Vin (P1-pin1) should be the primary power input for > power inputs other than battery or USB, and this input should have the > highest current handling capability of the three. > > So far, I find that Vin is approximately worthless. > Your mileage may vary. > So far, no reaction or comment from Jason or Robert. > > If you can, or can not, duplicate my observations, please comment. > > As far as a replacement for SYS_RESETn, I don't think that the external > 3V3 power appears until the system has booted, so you could use this > Voltage to gate things that might upset the boot process, or break things > prior to the CPU booting. > At least that is how it worked on the BBB, so I assume the same on the > PocketBone. > > --- Graham > > == > > On Friday, December 8, 2017 at 3:16:45 AM UTC-6, [email protected] > wrote: >> >> Nobody an idea? While searching through the board here I find two >> different opinions about VDD/where to apply external power to, so some >> clarification would be really nice... >> >> >> >> On Saturday, December 2, 2017 at 6:22:47 PM UTC+1, [email protected] >> wrote: >>> >>> Can somebody verify where the following pins/signals can be found at the >>> PocketBeagle (comparing to BeagleBone Black): >>> >>> - VDD (to supply externel power apart from USB) >>> - SYS_RESETn (signalling SiP is in reset state and no inputs are allowed >>> to be pulled to LOW or HIGH) >>> >>> ? >>> >>> 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 [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/e79f8f6c-d001-4662-9f45-d8291a55fac3%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
