On Monday, July 23, 2018 at 7:32:19 PM UTC-4, An Ra wrote: > > Hello all, > > I am using a PocketBeagle supplied only by a single cell LiPo. It powers > up normally after pressing the power button. > When I want to shut it down, I press once on the same button and it starts > to shut down. In the end, the PWR LED and the USR2 LED are on and stay on > (steady light). >
Can you capture a serial log? In my experience, it shuts down fine. > > When pressing the Power button for 10s, all the LEDs (PWR and USR0 to > USR3) turn off and then (after 1s) the PWR LED turns on automatically > followed by the other USR LEDs and the PocketBeagle powers up again. > (Compared to when only supplied through USB (no battery), all the LEDs turn > off and stay off unless I press the power button to power it up). > It is hard to catch the window of where it would stay off without doing the software power down. > > My questions are: > 1) Is the Pocketbeagle considered to be turned off properly at this stage > when PWR LED and the USR2 LED stay on after pressing once the power button? > (The voltage rails are still high.) > No. > 2) Is this a normal behavior? And does it have something to do with the > clamping circuit discussed here > <https://www.google.com/url?q=https%3A%2F%2Foctavosystems.com%2Fapp_notes%2Fosd335x-design-tutorial%2Fbare-minimum-boot%2Fclamping-circuit%2F&sa=D&sntz=1&usg=AFQjCNGZvIVeguQjWlpprTasMvDKxpiUXA> > ? > No. No. Something happened with the kernel during shutdown. Capture the log. One of the services or drivers didn't shut down properly. The PMIC should have been powered off. > 3) If not, how can I fix it (HW or SW solution)? I want the Pocketbeagle > to safely power down when I once press the power button. > It is a SW problem. Get the USB UART Click and capture the output. You might need to cut the power pin to avoid providing power via the Click. Also, don't leave it on there long and potentially damage the processor by driving the UART line. Maybe even cut the RX (Click Board to PocketBeagle) signal as well (since you only need to monitor). > 4) I think there is no way to get the voltage rails to 0V due to the 3.3V > bug. But, is it safe to always disconnect the battery in that state (PWR > LED and USR2 LED are on after pressing the PWR button to shut the > PocketBeagle down)? > Are you talking about the LDO? Doesn't make any impact on PocketBeagle if you don't use that 3.3V output. Not sure where the confusion is coming from. > > I am using the Stretch IoT Debian 9.4 version. > > 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/0a83ba5a-31a1-4ec6-ae20-500e60ac854c%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
