From: ags <[email protected]> Reply-To: <[email protected]> Date: Monday, May 12, 2014 at 4:04 PM To: <[email protected]> Subject: Re: [beagleboard] A simple cape to prevent power-interrupt corruption?
> So perhaps all I'll need is a small battery (recharged when DC power is > available) attached to the pads on the BBB, and some software. I am looking > for an orderly shutdown when DC power is removed - the sole purpose of the > battery is to provide power just until the BBB can be shutdown properly. No > need to be monitoring for a wakeup event (just power back on when DC power is > restored). Can you point me to any examples of how to monitor the DC status > (through I2C as you say below or any other way) and initiate the shutdown? > Thanks. You need to consider corner cases as well. For example, what happens if the power restores during the shutdown process or what happens if the power dies before BBB is fully booted. This isn¹t a trivial issue to resolve and I and others have written about this issue on this mailing list before. Ultimately, you need an external state machine to ensure reliable operations even when the unexpected occurs. Regards, John > > > On Friday, May 9, 2014 10:12:58 PM UTC-7, Ron B. wrote: >> ... >> So, for the shutdown, the cape itself doesn't do anything since that's a >> software issue. But since DC power status is reported through a status >> register over I2C, I used that in a bash script while toying with a "podcast >> car computer". I haven't spent much time on it but it definitely turns >> itself on and off with the car. I guess the other option would be a kernel >> module that monitors power good and initiates the shutdown... >> >> -Ron >>>>>> > > -- > 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.
