So I should also add that I'm not an electronics engineer by any stretch of the imagination. However, I do know various things about power, and digital electronics. Most of which I picked up from Wulfman, who has been an EE for 35+ years . . .
Digital electronics 101, a floating trace / line is a "bad" trace / line. So my reasoning on a trace that goes directly to a PMIC, on a trace that can control the PMIC to power and maybe reset the board . . . all it takes is a power fluctuation to reset the board . . . Everything "screams" this to me - However. Wulfman has looked through the datasheet for the PMIC, and even the schematics for the eval board of this PMIC( from TI ), and can not see why / how this would / could happen. Anyway, I have no idea how this PMIC is connected to the system through software. I *think* I remember reading something about it being connected through I2C1 . . . but that is a vague memory at best. I do remember that uboot can control the PMIC in the same way that the linux kernel does though. For whatever that is worth . . . On Sun, Jul 19, 2015 at 10:40 AM, evilwulfie <[email protected]> wrote: > I Powered one from a USB power supply only with no random reboots > > > > On 7/19/2015 9:45 AM, Graham Haddock wrote: > > Yes, I will go run the USB-Power test. > > I guess my question is... are you are powering your BBB from the USB port > on a computer, or, are you powering your BBB via the USB port from > something like a power supply or cellphone charger, which does not have a > computer and USB driver in it. > > If you are powering the BBB from a computer, and that computer has the > BBB driver on it, that allows you to see the BBB's internal web site, etc, > then, even though you are not using it, when you plug it in, the driver > comes up and starts polling the BBB at 1000 times per second, to see what > is going on. A lot is happening at the lower levels of USB that take time > to service on the BBB. > > --- Graham > > == > > On Sun, Jul 19, 2015 at 11:14 AM, William Hermans <[email protected]> > wrote: > >> *Or, are you just powering it via the USB connector and not >>> using/engaging the USB subsystem in the BBB?* >> >> >> Not sure if g_multi or g_ether is setup on this image. In either case, >> I'm only using ethernet. I'll look though. *looks* >> >> *Looks like the answer is "no".* >>> >>> *debian@beaglebone:~$ lsmod* >>> *Module Size Used by* >>> *snd_soc_evm 5854 0* >>> *omap_rng 5140 0* >>> *rng_core 8755 1 omap_rng* >>> *snd_soc_davinci_mcasp 18528 2* >>> *snd_soc_edma 1166 1 snd_soc_davinci_mcasp* >>> *snd_soc_hdmi_codec 2514 1* >>> *uio_pdrv_genirq 3657 0* >>> *uio 9930 1 uio_pdrv_genirq* >>> >> >> Anyway, I can understand that you may not want to use USB to power the >> device. However as a test to see if vbus / vusb is floating . . . this can >> not really hurt to power via USB for a little while during tests. >> >> Once it is established that this problem is related or not, then you >> and others can act accordingly. Grounding the necessary lines, or not. >> >> This really makes sense to me though, at least from my own perspective. >> Since I'm not having the problems you all are having with the same kernels. >> Passed that, if it does not pan out. Well, a little wasted time, but well >> worth the effort considering this problem seems to plague several people. >> Easy enough to test anyway . . . >> >> On Sun, Jul 19, 2015 at 9:00 AM, Graham Haddock <[email protected]> >> wrote: >> >>> My advice to Erik is that, if he has something important to do, to go >>> back to an official release. He should use a "Beta" release only if he can >>> afford the additional problems it might bring, and in this case there are >>> some. In my application for the BBB, I do not use or want to use the USB >>> connector. The previous kernels worked fine with the +5V power. Although >>> the +5V versus USB power behavior could be an important clue to what the >>> problem is. >>> >>> == >>> >>> When you say "powered by USB" are you also running the USB g_multi >>> interface to a PC and engaging the driver in the PC? >>> >>> Or, are you just powering it via the USB connector and not >>> using/engaging the USB subsystem in the BBB? >>> >>> I think there are (at least) two variables here. >>> >>> I will go power my BBB via the USB connector, which will power the >>> Vusb line, but without any USB activity on the USB connector and see what >>> happens. >>> >>> I agree that systemd is not the likely problem, since kernel 3.14 uses >>> systemd, and works fine, USB or +5V connector. >>> >>> My personal observation is that the less the BBB is doing, the more >>> likely the self-reboot is to happen. >>> If I turn off the four blinking blue LEDs, with the BBB not doing >>> anything else, the reboots seem to happen more often. >>> So, if you are powering the USB connector from a computer, it may be >>> the USB activity, not the power source that is changing the behavior. >>> >>> --- Graham >>> >>> == >>> >>> >>> >>> On Sun, Jul 19, 2015 at 10:11 AM, William Hermans <[email protected]> >>> wrote: >>> >>>> Graham, thats where you're wrong. I've been using all those testing >>>> kernels EXACT SAME KERNELS you've been having troubles with. Except, I'm >>>> not having troubles with them. Why ? Becasue I'm powering via USB. >>>> >>>> So if you REALLY want to prove the problem this won't work for *you* >>>> try powering via USB . . . >>>> >>>> On Sun, Jul 19, 2015 at 7:55 AM, Graham <[email protected]> wrote: >>>> >>>>> Eric: >>>>> You never said what you were trying to do with the BBB, and why you >>>>> need Debian 8.1/kernel 4.x.x. >>>>> As you have seen, it is temporarily broken, but is being worked on. >>>>> This is a "test" release, and not recommended for active use, unless you >>>>> like adventures, like you are having. >>>>> >>>>> If you need the capemanager, consider Debian 7.8/kernel 3.8 >>>>> >>>>> If you don't need the capemanager, but need some other benefit of >>>>> Debian 8, then use Debian 8.x and kernel 3.14. >>>>> >>>>> Both of these options are solid, do not reboot by themselves, and >>>>> don't care whether it is powered from the 5V barrel connector or USB. >>>>> --- Graham >>>>> >>>>> == >>>>> -- >>>>> 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]. >>>>> 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 a topic in >>>> the Google Groups "BeagleBoard" group. >>>> To unsubscribe from this topic, visit >>>> https://groups.google.com/d/topic/beagleboard/2yOpE3XYJ1Y/unsubscribe. >>>> To unsubscribe from this group and all its topics, send an email to >>>> [email protected]. >>>> 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]. >>> 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 a topic in the >> Google Groups "BeagleBoard" group. >> To unsubscribe from this topic, visit >> https://groups.google.com/d/topic/beagleboard/2yOpE3XYJ1Y/unsubscribe. >> To unsubscribe from this group and all its topics, send an email to >> [email protected]. >> 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]. > 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]. > 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. 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