Automatic Power Up

Moderator: nferre

travisgriggs
Posts: 6
Joined: Wed Sep 17, 2014 6:38 pm

Automatic Power Up

Thu Jan 29, 2015 1:04 am

I have an xPlained board as part of a little hobby project. I'm running Debian Jesse. Things are working mostly good, but when I lose power and then power comes back on, the board doesn't start up unless I press either the wake or reset buttons. I am running off of 5V power supply soldered in at the 5V_Ext points. I'm running off of the SD Card for now. Is this a hardware thing? Some expected behavior of the board? Or is it something in my uBoot configuration? Or something in the Linux kernel configuration?

I really just want it to reliably power back on whenever it experiences a power blip.

I'm not sure what other specifics to provide, but can try if someone points me at it...
travisgriggs
Posts: 6
Joined: Wed Sep 17, 2014 6:38 pm

Re: Automatic Power Up

Thu Jan 29, 2015 2:09 am

I knew once I posted, an answer would turn up. I'll share just in case it helps someone else long run. I have some other components attached to the same power supply. One of them has a large super cap designed to smooth its operation when powered by a battery. That cap was large enough that the power up voltage ramped up slow enough that the PMU didn't see enough of an edge to trigger a reset. Once the cap was clipped, everything worked as wanted.

Sorry for the noise. 

Return to “SAMA5-based”

Who is online

Users browsing this forum: No registered users and 2 guests