I use the Beagle Bone Black in a project, it is mains powered with a source we developed and has a lead-acid battery (not appropriate) for backup when the power does not supply energy that would be only in the event of a fall or a shutdown scheduled for maintenance, so the system does not hang up. However when we detect a power outage the backup battery kicks in and the system correctly turn off after a period thus preventing the system files get corrupted.
Ideally enjoy the Beagle Bone Black system to feed her through a cell Li + of 4.2V, I need is to find out how I can make the detection of power outages and turn this battery after about 10 minutes, just as we do with the lead battery, it all via firmware.
I am using it with a rechargeable lithium battery and am able to detect power outages (via i2c) and shutdown/restart beaglebone - it has several neat features and if I recall correctly you can read the battery levels as well.
There is a battery input on the pmmc that you can use, it is for a
single cell 3.7v Li battery. or more in parallel if you need more
holding time.
one battery will give you plenty of time for a orderly shutdown http://www.ti.com/lit/ds/slvsb64g/slvsb64g.pdf
ref page 2 of the BBB schematic upper right part of page
There is a battery cape that seems to do what you want http://andicelabs.com/beaglebone-powercape/
this board does not use the pmic power pins
Lords am new to the BBB and what I need is to turn off the battery management so that when my system is not connected to battery is not consumed in its entirety.
Yup, that’s what I do with the powercape from Andice Labs as mentioned above. Except for very low drain battery is essentially disconnected.
I initially went the route of trying to use the onboard battery connector but it’s not really a decent solution if you want solid system and battery management.
Just out of curiosity. What is the attraction of a “battery cape” ? I mean I can see the need for consistent power, and perhaps keeping this as small as possible, but is that it ?
I have always imagine using an “inline” power source such as a regulated battery output to the barreljack, with a small inline mains to battery charging circuit. But . . . yeah that’s me.
Anyway my comment is not meant to discourage, or discount other avenues of thought. I’m simply curious.
Just out of curiosity. What is the attraction of a "battery cape" ? I mean
I can see the need for consistent power, and perhaps keeping this as small
as possible, but is that it ?
The main advantage if an integrated solution is that you get to monitor the
supply and the battery from the manager chip. This way you can shut yourself
down cleanly when the battery is about to give up, and go into power save mode
when not running on the mains.
My original reasoning behind the Power Cape was to get a 5V supply with a low quiescent “off” current and that could restart the BeagleBone on a scheduled timeout or external event. Using a 5V supply instead of the PMIC’s battery interface also allows for using USB devices. The battery charger was added after the first prototype.
As David pointed out, the INA219 allows system software to monitor the battery voltage & current and take appropriate action. DC “power good” from the charger is also available and can trigger power-up allowing the BeagleBone to restart when power is restored. The micro-controller does a few other things like RTC, WDTs, power-up retries, and holding reset during power-up intended to make the system more reliable for remote operation. The firmware is on Github if you need to customize behavior.
My original reasoning behind the Power Cape was to get a 5V supply with a low quiescent “off” current and that could restart the BeagleBone on a scheduled timeout or external event. Using a 5V supply instead of the PMIC’s battery interface also allows for using USB devices. The battery charger was added after the first prototype.
As David pointed out, the INA219 allows system software to monitor the battery voltage & current and take appropriate action. DC “power good” from the charger is also available and can trigger power-up allowing the BeagleBone to restart when power is restored. The micro-controller does a few other things like RTC, WDTs, power-up retries, and holding reset during power-up intended to make the system more reliable for remote operation. The firmware is on Github if you need to customize behavior.
All this can be done without using a cape. Whats more, using a single msp430g2553, and a few GPIO’s you can have all of that, plus a watchdog reset, and whatever else you can dream up.
So, I suppose the cape is just a matter of convenience. Which, there is nothing wrong with that, and I’ve been accused many a time of coming up with elaborate / extravagant solutions. When a simpler / easier one will do . . .