On Thu, May 25, 2017 at 1:10 PM, Robert Nelson <[email protected]> wrote:
> On Thu, May 25, 2017 at 3:08 PM, jmelson <[email protected]> wrote: > > > > > > On Thursday, May 25, 2017 at 2:05:44 PM UTC-5, William Hermans wrote: > >> > >> Use an inline battery, e.g. between "AC in" and the barrel jack or > header > >> power input. Or put a battery on the test points as you mentioned. > Granted, > >> if you put a battery on the test points, you'll also need to > occasionally( > >> maybe always ?) toggle SYS_RESET before the power button will work. > >> > > And, what happens when the user just turns off the power? The battery > > drains, and then the Beagle Bone crashes and the battery is left totally > > drained, which ruins it, too. > > Doesn't sound like a solution. > > Sounds like someone needs to design-in a front end to handle that... ;) > "Somebody" has ;) But i guess some need things "spelled out" in detail ? Basically, you need an MCU that detects power in, that cuts power to the beaglebone from the battery after a set amount of time. *Or* that communicates between it's self and the beaglebone, which "Says" "Hey buddy battery is getting low you need to power down now!". The tricky part with the latter part here is how does the MCU know when the beaglebone is powered down ? I can think of a couple ways at least . . . Secondly, you'll need to basically code watchdog functionality into this MCU, so you know how to spot an improper power cycle, then toggle SYS_RESET, and then toggle the "power button". To make sure the board does in fact come up. Again, how does one do this ? By Being creative . . . I've done this with an MSP430, and I know of at least one other person(company ) that uses a PIC micro to do essentially the same thing I'm doing. With a cape for sale, in the context of a "UPS" style cape. He's posted a link to this cape before. We've(my buddy and I ) have been talking about this for years, and finally implemented hardware and software about a year ago. It works for us. Ideally, I think the best solution is to design something like I think Gerald was talking about some time ago, and something he actually made at one point I think. A real UPS, that sits before the 5vdc input to the board. This way if you need USB in your application, nothing gets disturbed. Then the board need not be "worried" about "Hey the PMIC says power went away, I need to shut down". In our own case we do have some devices that do need USB for a3G/4G modem that doesn't cost one their first born child. But in this case, the system they're controlling is also powered by AC, and it's a moot point. So other than contacting an external server to tell it the system is down. There's nothing left to do, but to wait it out(by powering down ). But honestly guys, come on, there about 5 billion ways to deal with this situation Be creative. -- 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/CALHSORq1a4XeBWCLM0bc4%2BS9hk5kU-Xur%3DWga3ugsMh0je4adg%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
