I guess it is all about prospective. Perhaps for your application you are right. However, if you have 10K or 100K or more devices installed, and now you have to recall them all because they keep on going offline, then it isn’t a $5 problem.
Regards, John > On May 16, 2016, at 12:46 PM, evilwulfie <[email protected]> wrote: > > 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 < >>> <mailto:[email protected]>[email protected] >>> <mailto:[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] >>>>> <mailto:[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 >>>>>> <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 >>>>>> <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 >>>>>> <mailto:[email protected]>[email protected] >>>>>> <mailto:[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 >>>>>> >>>>>> <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 >>>>>> <https://groups.google.com/d/optout>. >>>>> >>>>> >>>>> -- >>>>> 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 >>>>> <mailto:[email protected]>[email protected] >>>>> <mailto:[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 >>>>> >>>>> <https://groups.google.com/d/msgid/beagleboard/976bd440-2729-5157-8692-3357a8d607a0%40gmail.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 >>>> <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] >>>> <mailto:[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 >>>> >>>> <https://groups.google.com/d/msgid/beagleboard/E00049D5-E39B-42CB-8A5E-A19F4E51199F%40gmail.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 >>> <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] >>> <mailto:[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 >>> >>> <https://groups.google.com/d/msgid/beagleboard/300489a5-a027-8f30-a598-89be5b17b4a4%40gmail.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 >> <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] >> <mailto:[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 >> >> <https://groups.google.com/d/msgid/beagleboard/7BFABDDC-D4D0-4E6F-863C-1015E9794658%40gmail.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 > <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] > <mailto:[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 > <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/E578F304-881C-4929-9E13-F886D69C62DD%40gmail.com. For more options, visit https://groups.google.com/d/optout.
