Hi

My aim is to build low power(battery powered) 3G surveillance camera based 
on Beagle Bone(or black) and I have done some research regarding power 
management of BB and those attentions goes for BBB too:

Using prebuild image included in AM335xSDK  07_00_00_00( 
http://software-dl.ti.com/sitara_linux/esd/AM335xSDK/latest/index_FDS.html) 
I can put BB in deep sleep giving command 

echo -n "mem" > /sys/power/state

After that current draw goes from ~210mA -> 150mA and BB wakes hapily up 
when I type any characters to console via USB-OTG

TI announces that power consumpion of AM335x is in deep sleep about 1mA so 
something is consuming current and I guess those are usb-circuits and 
lan-circuits at least. According BB RevA6 schematic 
<https://github.com/CircuitCo/BeagleBone-RevA6/blob/master/BEAGLEBONE_REV_A6A.pdf?raw=true>
 lan 
and usb are powered via rail VDD_3V3B so I enhtusiastically command PMIC 
with

i2cset -f -y 0 0x24 0x0b 0x6b; i2cset -f -y 0 0x24 0x16 0x1f;

which turns rail VDD_3V3B off BUT unhapily also affects system reset, 
because U14B in schematic is powered via VDD_3V3B! In BBB if I have 
understand the schematic right, both VDD_3V3B and VDD_3V3A tied together 
via PMIC and regulators enable-pin so both rails are on or off.

after issuing command

i2cset -f -y 0 0x24 0x0b 0x6b; i2cset -f -y 0 0x24 0x16 0x00

current consumpition is zero, so there is no quiescent current, which PMIC 
has no control(you can guess that White Bone is really black after that 
command :D ) 

So the after this scrambling I ask: is there something I have missed if I 
want to put BB or BBB deep sleep state with minimal power consumption and 
wake it up hapily with GPIO(this needs some config?) or it is overall 
possible with current schematics and if not is there coming new version of 
BBB where it is possible disable all unnecessary leak currents? 

Thanks for your interest,
Mikko Pakarinen


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