Why beaglebone black restarts after a shutdown ??

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1

Hi,

I have noticed that the beaglebone black starts up after a shutdown.

I have a C++ program running in the bbb, the bbb is backed by an external +5V battery pack. When the C++ program issues the following command to start the shutdown procedure of the bbb.

system(“shutdown -h now”);

exit(0);

This does shutdown the bbb completely sometimes, most times the bbb starts up again, the power led turns off but then after a second or two lights up again and then bbb starts up all over again (the output voltage from the power bank does not switch OFF, it remains ON for some time).

In my previous bbb systems I have not faced this problem.

It is my belief that the output voltage from the power bank has a sudden dip, this causes the bbb to detect a new power cycle.

I am not sure though if I am correct…

Could anyone enlighten me on this problem ???

I am sorry if the above problem sounds vague…

thanks
a

2

Yes it does sound vague. I would hook a scope to the power and see what it does in the reset scenario. What is your current capacity of your power source?

If the power pin is held down too long, it will result in a power cycle and not a shutdown.

Gerald

3

The power bank is rated for 5 V, 1 amp.

I am going to check with a scope tomorrow…

thanks
a

4

Hi,

I have noticed that the beaglebone black starts up after a shutdown.

I have a C++ program running in the bbb, the bbb is backed by an external +5V battery pack. When the C++ program issues the following command to start the shutdown procedure of the bbb.

system(“shutdown -h now”);

exit(0);

Try “halt” instead.

Regards,
John

5

thanks I will try that out.

6

I tried that, and it still automatically restarted. Any ideas?

7

I tried that, and it still automatically restarted. Any ideas?

I’m running Debian with V3.8.13-bone41 and my BBB shuts down and powers off when I enter “halt”

To power up again, I click on the power button.

Regards,
John

8

Hi all,

I have the exact same problem with BBB when the board is powered with a 5V 2A source, but no problem is the board is usb powered.
I was wondering if the problem had been solved problem ?

Regards,

9

when the board is powered with a 5V 2A source
I confirm this! Never tried to use USB power

Kernel 3.8.13-bone67

10

Hi,

Did anybody find the cause for the restart?
My BBB has the same problem, my adapter is 5V 2A and there is definitely no restart issue with USB power.
I’m running Debian 3.8.13-bone70.

Thanks.

11

Hi,

Did anybody find the cause for the restart?
My BBB has the same problem, my adapter is 5V 2A and there is definitely no restart issue with USB power.
I’m running Debian 3.8.13-bone70.

Thanks.

12

Hi,

Did anybody find the cause for the restart?
My BBB has the same problem, my adapter is 5V 2A and there is definitely no
restart issue with USB power.
I'm running Debian 3.8.13-bone70.

From what I remember, and I can be quite wrong, it goes something like
this:

USB power is monitored.

With external 5V supply, the processor is fed, but the USB power input
is still monitored. If it is read as being "absent" then the
processor reboots due to a perceived power failure. The power monitor
chip apparently decides that the USB (as in main power) has failed,
shuts the processor down, detects that 5 volts is there, boots the
processor back up.

Some people made a shorting plug that simply shorts USB power to
ground (in which case it was never "up" and is not checked).

You could "ground" it through a 100 ohm resistor in a dummy plug, or
perhaps a 1K resistor from USB VCC to ground. 100 ohms would draw 50
ma when installed on the board and then connected to VCC (10% drain),
and 1K ohms would draw 5 ma (1% power), and might work just as well.

Just what I seem to remember from the discussions.

Harvey