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] >> <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]> 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 >>>>> --- >>>>> 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/c7fb39d8-84ef-4127-9db8-cd65a6965e31%40googlegroups.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] >>>> <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. >>>> 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] >>> <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. >>> 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] >> <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 >> <https://groups.google.com/d/msgid/beagleboard/300489a5-a027-8f30-a598-89be5b17b4a4%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. > 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 > <https://groups.google.com/d/msgid/beagleboard/7BFABDDC-D4D0-4E6F-863C-1015E9794658%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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