Gerald what is your opinion on this subject ? Le lun. 16 mai 2016 21:46, evilwulfie <[email protected]> a écrit :
> spend 50 bux on a power supply to solve a 5 dollar problem yeah right. > > > > On 5/16/2016 12:34 PM, John Syne wrote: > > > On May 15, 2016, at 4:25 PM, evilwulfie < <[email protected]> > [email protected]> wrote: > > msp430 has an internal watchdog > > And so does the AM3358, so I’m not sure whats your point? If it is a > micro-controller, it is not guaranteed to boot up successfully every time, > given an unstable power supply. To start with, you need to make the power > supply more predictable so that brown outs, dips and sags are not seen by > the micro-controller and that power down only occurs if the input power > fails for more than a specified time. Also, if you do start a shutdown, > then a full power cycle is needed in a controlled manner. When input power > returns, don’t boot until the input power looks reliable. > > This is where you need an understanding of how the power utility network > operates, which includes understanding how protection operates, what an ARC > (Automatic Reclosure Relays) do, etc. For example, when a large breaker > trips due to a protective signal, the ARC will attempt to reclose that > breaker, sometimes more than once. At night, in a storm, you will see your > lights dim for a second or two; that is an ARC operation. When a > transformer has water in the oil or when a insulator is arching, or a power > line is arching on the ground, these all result in very strange power > behavior. In summary, power failure isn’t just an on or off problem, but a > multitude of more problematic cases. > > Regards, > John > > > On 5/15/2016 3:37 PM, John Syne wrote: > > > On May 15, 2016, at 3:14 PM, evilwulfie <[email protected]> wrote: > > We use an external msp430 for our intelligent watchdog > > So who or what monitors the MSP430? Since it is a micro-controller, it is > easy to get it into a lock situation. All you need is a programable power > supply which will ramp up and down the voltage into the micro-controller at > predefined times and it will lock and become completely unresponsive. > Granted this will rarely happen, but in our applications where 100K or more > devices are installed, we cannot accept some devices locking up because of > a power failure. > > Regards, > John > > > > On 5/15/2016 1:07 PM, Super Twang wrote: > > > > I've just come across this conversation in my own search for a rock-solid, > embeddable configuration for the BeagleBone Black. I’m trying to develop > an embedded controller device that needs to live behind walls, in ceilings > and in other inaccessible places. ( It is for the automation of art & other > electronic installations.) > > From what I gather here, the BBB is not quite up to the task, without an > external watchdog circuit (please correct me if I’m misreading this thread). > > @John3909: Your suggestion of the GreenPak prompted my own discovery of > that tech — it looks great, esp the ecosystem of tools around the platform. > > In looking around, I found some Silego application notes that implement a > hardware watchdog for MCUs. > http://www.silego.com/products/352/312/AN-1058.html This might be a > useful starting point for anyone using GreenPak for a hardware watchdog. > > @John3909: Does this design look like it might be a good fit for the BBB? > (Not knowing how to read GreenPak internals, it is not obvious to me) > > Alternately, I'm wondering in the two years that have passed since this > thread started, if anyone has developed a hardware watchdog design for the > BBB they'd be willing to share. An open-source hardware watchdog for the > BBB would go a long way towards ameliorating the hardware issues with the > PMIC on RevC, and allow it to prosper as a base for applications where > long-term reliability matters. > > Although I’m first and foremost a software engineer, I've got some > electronics chops (albeit mostly digital), but (sadly) very limited > hardware design equipment (oscilloscope, etc). [That said, I have iron, > and will solder!] I’d be happy to develop & contribute the software > components for such a system (I’d envision a library + device tree overlay) > if someone(s) else would like to partner up to design the hardware side. > > Best, > > ST > > -- > For more options, visit <http://beagleboard.org/discuss> > 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]> > [email protected]. > To view this discussion on the web visit > <https://groups.google.com/d/msgid/beagleboard/c7fb39d8-84ef-4127-9db8-cd65a6965e31%40googlegroups.com> > https://groups.google.com/d/msgid/beagleboard/c7fb39d8-84ef-4127-9db8-cd65a6965e31%40googlegroups.com > . > For more options, visit <https://groups.google.com/d/optout> > 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]> > [email protected]. > To view this discussion on the web visit > <https://groups.google.com/d/msgid/beagleboard/976bd440-2729-5157-8692-3357a8d607a0%40gmail.com> > https://groups.google.com/d/msgid/beagleboard/976bd440-2729-5157-8692-3357a8d607a0%40gmail.com > . > 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/E00049D5-E39B-42CB-8A5E-A19F4E51199F%40gmail.com> > https://groups.google.com/d/msgid/beagleboard/E00049D5-E39B-42CB-8A5E-A19F4E51199F%40gmail.com > . > 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/300489a5-a027-8f30-a598-89be5b17b4a4%40gmail.com?utm_medium=email&utm_source=footer> > https://groups.google.com/d/msgid/beagleboard/300489a5-a027-8f30-a598-89be5b17b4a4%40gmail.com > . > 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/7BFABDDC-D4D0-4E6F-863C-1015E9794658%40gmail.com?utm_medium=email&utm_source=footer> > https://groups.google.com/d/msgid/beagleboard/7BFABDDC-D4D0-4E6F-863C-1015E9794658%40gmail.com > . > 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/4b8c4f6e-abae-446c-d964-26d37b92d4b3%40gmail.com > <https://groups.google.com/d/msgid/beagleboard/4b8c4f6e-abae-446c-d964-26d37b92d4b3%40gmail.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. 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