>
> *As someone already posted, this is a bit more complicated than that, but
> I get the idea.*
>
I did not see anyone other than you, I, and Gerald post on your discussion
here. But I do not get every post to this group..
But, sure . . . it is not as simple as that because while the board is
still being powered, a shutdown now -h will keep one from being able to
reset the board remotely. This applies to being powered by battery too.
In this case, where the board is being powered by a battery, super cap, or
whatever. You need an external "device" to break VIN to the board. Or this
would be a perfect example of why having a hard reset tied to a test point,
or header pin would be beneficial. But we do not have this feature, so
externally is a must.
As for the software. Everything is already in place except for one small
piece. A userspace app that monitors the systems interrupts, particularly
for the PMIC. Something similar to acpid( a daemon ), or whatever you
prefer.
william@beaglebone:~$ cat /proc/interrupts
CPU0
16: 2671562 INTC 68 Level gp_timer
. . .
179: 20 INTC 7 Level tps65217
Err: 0
william@beaglebone:~$ cat /proc/irq/179/spurious
count 0
unhandled 0
last_unhandled 0 ms
Is pretty straight forward, and obvious. Things get a bit more complex, and
interesting where the external solution is concerned. It is solvable
though, we have solved it.
On Mon, May 2, 2016 at 11:55 AM, Yiannis Papelis <[email protected]> wrote:
> As someone already posted, this is a bit more complicated than that, but I
> get the idea.
>
> On Monday, May 2, 2016 at 2:09:44 PM UTC-4, William Hermans wrote:
>>
>> *Use a super capacitor.*
>>>
>>
>> Ok, a little abstract . . .
>>
>> Use a super capacitor, and if using a console image . . . sudo apt-get
>> install acpid
>>
>> Then the board will automatically shutdown when 5V input goes missing.
>> I'd make sure you pick a super cap that can sustain the beaglebone for ~30
>> seconds, even if not needed. Just in case. Typically though, here, we see
>> that the board shuts down within 5 seconds or so. Maybe slightly longer.
>>
>> On Mon, May 2, 2016 at 10:47 AM, William Hermans <[email protected]>
>> wrote:
>>
>>> *I have been building embedded systems for a while now and I am
>>>> considering using the beaglebone (BBB) for an upcoming project, but I am
>>>> confused by everything I read regarding the shutdown requirements. As an
>>>> embedded system the only way to turn it off is to simply shutdown the power
>>>> with a switch, yet my preliminary research indicates that this is a no-no
>>>> as it may damage the BBB and/or corrupt the file system. I also read a lot
>>>> of comments regarding voltage on the pins after a shutdown; in my case,
>>>> very likely there will be a CAT5 cable with live activity connected even
>>>> after power down; assume the magnetics should protect the BBB, but just
>>>> checking.*
>>>>
>>>
>>> This is true of any system running an OS that is not red only. If you
>>> unceremoniously yank the power, you're asking for trouble.
>>>
>>> *I have used quite a few micro controllers and various self-standing
>>>> systems, but am fairly new to the BBB - still mostly reading about it. Am
>>>> I missing something? How can a device meant to be used in embedded systems
>>>> not be tolerant of power loss and be so finicky about power?*
>>>>
>>>
>>> It sounds like you're missing a lot. It sounds like you've had a lot of
>>> experience with small micros, that run bare metal, but have have no, or
>>> limited experience with using an embedded OS.
>>>
>>> Then if you stop and think of the cost of this board, and what the goal
>>> of beagleboard.org was when the board was created. Perhaps then it
>>> become clear as to how / why we're where we are in this context. You can
>>> fix all of this yourself, using external hardware, and custom software.
>>>
>>>>
>>>> *By the way, I can see there is a battery backup circuit but I do not
>>>> want to use a lithium battery for safety/temperature/cost reasons. Using a
>>>> large capacitor also seems tricky as the shutdown may take a few seconds so
>>>> I don't see how that will work.*
>>>>
>>>> *Any suggestions would be greatly appreciated.*
>>>
>>>
>>> Use a super capacitor.
>>>
>>>
>>>
>>> On Mon, May 2, 2016 at 8:39 AM, Gerald Coley <[email protected]>
>>> wrote:
>>>
>>>>
>>>>
>>>> On Mon, May 2, 2016 at 10:36 AM, Yiannis Papelis <[email protected]>
>>>> wrote:
>>>>
>>>>> I have been building embedded systems for a while now and I am
>>>>> considering using the beaglebone (BBB) for an upcoming project, but I am
>>>>> confused by everything I read regarding the shutdown requirements. As an
>>>>> embedded system the only way to turn it off is to simply shutdown the
>>>>> power
>>>>> with a switch, yet my preliminary research indicates that this is a no-no
>>>>> as it may damage the BBB and/or corrupt the file system. I also read a
>>>>> lot
>>>>> of comments regarding voltage on the pins after a shutdown; in my case,
>>>>> very likely there will be a CAT5 cable with live activity connected even
>>>>> after power down; assume the magnetics should protect the BBB, but just
>>>>> checking.
>>>>>
>>>>> I have used quite a few micro controllers and various self-standing
>>>>> systems, but am fairly new to the BBB - still mostly reading about it. Am
>>>>> I missing something? How can a device meant to be used in embedded
>>>>> systems
>>>>> not be tolerant of power loss and be so finicky about power?
>>>>>
>>>>> By the way, I can see there is a battery backup circuit but I do not
>>>>> want to use a lithium battery for safety/temperature/cost reasons. Using
>>>>> a
>>>>> large capacitor also seems tricky as the shutdown may take a few seconds
>>>>> so
>>>>> I don't see how that will work.
>>>>>
>>>>> Any suggestions would be greatly appreciated.
>>>>>
>>>>> --
>>>>> For more options, visit http://beagleboard.org/discuss
>>>>> ---
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>>>>> To view this discussion on the web visit
>>>>> https://groups.google.com/d/msgid/beagleboard/4b2dc307-631d-405d-88d6-7537adb3ac29%40googlegroups.com
>>>>> <https://groups.google.com/d/msgid/beagleboard/4b2dc307-631d-405d-88d6-7537adb3ac29%40googlegroups.com?utm_medium=email&utm_source=footer>
>>>>> .
>>>>> For more options, visit https://groups.google.com/d/optout.
>>>>>
>>>>
>>>>
>>>> Main reason for the shutdown process is the corruption of the Linux
>>>> file system.
>>>>
>>>> If you have power on any signal when the processor is shutdown, then
>>>> you are asking for trouble.
>>>>
>>>>
>>>> http://www.elinux.org/Beagleboard:BeagleBoneBlack#Expansion_Header_Pin_Usage
>>>>
>>>>
>>>> Gerald
>>>>
>>>> [email protected]
>>>> http://beagleboard.org/
>>>> [email protected]
>>>>
>>>> --
>>>> For more options, visit http://beagleboard.org/discuss
>>>> ---
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>>>> To unsubscribe from this group and stop receiving emails from it, send
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>>>> <https://groups.google.com/d/msgid/beagleboard/CAHK_S%2BergZ8%2BPd5zBdxsHqJDzQphgPXKXF0oayzjV1PVHPY8kw%40mail.gmail.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
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> .
>
> For more options, visit https://groups.google.com/d/optout.
>
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