Hello everybody,
I am using a BeagleBone Black version A6A with Debian distribution on a µSD card.
debian@beaglebone:~$ uname -a
Linux beaglebone 3.8.13-bone50 #1 SMP Tue May 13 13:24:52 UTC 2014 armv7l GNU/Linux
I want to avoid BBB shutdown during power outage. Therefore a battery backup is directly connected to BBB as described on the following link: BeagleBone Black UPS
Unhappily, as soon as a power outage occurs, the BBB performs a clean shutdown within approx. 60 seconds as battery is still connected.
In fact, quite a lot of applications must still run during and after power outage.
I didn’t find in the BBB reference manual and documentation any tips related to “no shutdown” procedure. When Googling, every topic, I could find, is related to the way shutdown occurs. Monitoring battery level before shutdown procedure also exists on some forums but nothing preventing shutdown when a battery backup is available. I must admit that I am not skilled enough to handle very complicate programming tasks. Therefore trying to dig in source code is difficult. I only use Python for basic tasks.
I tried Angström distribution installed on the BBB (Rev A6A) and encountered the same shutdown problem when removing 5V DC power supply.
There is an interesting Power Cape on the market that may be configured for different BBB behaviours. It is certainly the best solution. But I want to keep budget and power consumption as low as possible.
Last comment to avoid misunderstanding: for my application, during power outage, I only need 3.3V power supply…not 5V.
Only Ethernet interface and some GPIO are used.
Does anyone knows how to avoid this shutdown procedure? Some guidelines would be appreciated
Kind regards
Michel.
No shutdown is a function of the SW. The SRM covers the hardware. No shutdown means you have enough battery power to keep running until power is restored. You would need to add that function into your SW.
Gerald
Thank you for your quick reply.
Nope you need to tell it..
Either via: "sudo halt" or.. setup a pin/interrupt to trigger systemd
to shutdown the system..
Regards,
Hello Robert,
Thank you spending your time to help me.
First of all, sorry if I didn’t explain things correctly. I think there is a misunderstanding (I am French speaking) .
I don’t want BeagleBone to perform a shutdown during power outage. I want BBB running continuously like my VoIP PBX also based on BeagleBone Black. But I think, that in this later case, the developper used Ubuntu (neither Debian nor Angström). As these OS are official BBB OS, I prefer using them for my application. I am electrician, I don’t really want to spend too much time on SW bugs as I am not skilled for that task.
One word perhaps about the application: it is very simple. I must monitor mains power supply in different locations and have to log power outage events on a file with time stamps. I have also to log grid switching events … The specialized 230V AC monitoring system has no Ethernet connection but can be associated with BBB GPIO’s. So that log file could be downloaded when power outage is over.
The problem is that, even with battery plugged in, the BeagleBone Black perform a self shutdown within 60 seconds after mains power off (5V DC power supply)…
Hope my explanation is now better.
Kind regards
Michel.
Maybe use a battery backup UPS to run your 5 volt power supply to the BBB?
-david
Hello David,
Yes you are right. If I cannot solve this shutdown problem it’s probably the only solution.
But it’s frustrating when you think that the BeagleBone Black has its own battery charger and own UPS that can only run during 60 seconds because of this self shutdown problem !
Why does it work correctly on a BBB running a VoIP PBX (probably running with Ubuntu) and not with a Debian or Angström distribution ?
I would prefer Debian or Angström built for BeagleBone Black distribution not to be able to make a self shutdown and let this possibility to the user.
An external backup UPS draws also additional current when running. I wanted to keep power consumption as low as possible. Moreover, I don’t need 5V from the BBB when running under UPS mode.
If a know that a SW solution exists, I won’t give up so easily. 
Kind regards
Michel.
Hello there Michael,
I have just tested my BeagleBone Black. I have connected the power through USB + battery. Then I disconnected the USB and left the BeagleBone Black on the battery. It havent shutdown after a minute or anything. I am using the console Debian image.
W dniu piątek, 17 października 2014 07:25:54 UTC+2 użytkownik Michel Gerin napisał:
Hello bremerpl,
GREAT !! you had the correct suggestion.
I installed the console version and BBB seems indeed not to shutdown.
I didn’t know these different behaviours between the ldxe and console version when a battery backup was installed on the BBB
Thank you for your help.
Kind regards
Michel.