Can you generate a plot of the power applied on P1_1? I suspect some additional bulk capacitance might be required to keep it sufficiently stable. Monitoring the RESET# line at the same time as P1_1 would be ideal.
I'll try to reproduce next week. I only ever tested with a bench supply and not for extended durations. Given the similarity to the BeagleBone Black circuit, it doesn't seem so necessary, but let's make sure the input is sufficiently stable as much of the capacitance that was there is now gone. On Monday, December 4, 2017 at 9:11:42 AM UTC-5, Graham wrote: > > P1-pin7 is the 5V power input normally associated with power coming in the > USB connectors. > In the case of the PocketBeagle, it is the input from the USB0 connector. > It can be used as either a 5V input or, if there is power coming in USB > port0, as a power output for USB port 1. > It is just a straight connection. > > It happens to work fine, and does not seem to have the stability problem I > am seeing on P1-pin1. > > --- Graham > > == > > On Mon, Dec 4, 2017 at 1:23 AM, <[email protected]> wrote: > >> >> >> On Sunday, December 3, 2017 at 4:21:33 PM UTC+1, Graham wrote: >>> >>> The PocketBeagle, when powered only by the Vin input (P1-pin1) is >>> unstable. >>> This is the power supply input, normally assigned to the barrel jack in >>> the BBB, or the AC adapter input in the TI docs. >>> >>> Not to be confused with the Vi input (P1-pin7) which is connected to >>> Vusb0 and Vusb1 on the PocketBeagle. >>> >> >> I'm not quite sure but isn't P1/7 the same as VDD on the BBB? In this >> case you definitely shouldn't use P1/1 for powering the board... >> >> >> -- >> For more options, visit http://beagleboard.org/discuss >> --- >> You received this message because you are subscribed to a topic in the >> Google Groups "BeagleBoard" group. >> To unsubscribe from this topic, visit >> https://groups.google.com/d/topic/beagleboard/8Y5COfcW-Ok/unsubscribe. >> To unsubscribe from this group and all its topics, send an email to >> [email protected]. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/beagleboard/9de62b40-9e5c-459f-b258-8e500aa43a31%40googlegroups.com >> >> <https://groups.google.com/d/msgid/beagleboard/9de62b40-9e5c-459f-b258-8e500aa43a31%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> >> 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 [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/93ed0edb-b244-4a3c-a91c-496e7c6d2d9d%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
