On 5/27/14, 10:45 AM, "Dr. Michael J. Chudobiak" <[email protected]> wrote:
>> A battery powered >> cape for a graceful power-down might be option. I don't have the >> knowledge to design/build one (relatively) easily. > >On the BeagleBone white, I use a 5F supercap on the "battery" terminals. >When my hardware detects failing prime power it flags an input that my >software watches for. My software then immediately uses the magic-sysrq >to sync disks and remount as read-only, to protect the filesystem. The >supercap provides just enough power/time to do that. I really don¹t see how this can work. First, the supercaps are 2.5v so you need two in series which means you need an energy balance circuitry to ensure one supercap doesn¹t receive more charge than the other. Also, the PMC won¹t like a short circuit, which the supercap is when it is fully discharged. I could go on, but this idea doesn¹t make sense to me. Regards, John > >Also, I use full data+metadata journaling on the filesystem (ext4). > >It's been very robust so far. > >- Mike > >-- >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.
