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crowd-funded eco-conscious hardware: https://www.crowdsupply.com/eoma68


On Mon, Aug 29, 2016 at 8:15 PM, Raphaël Mélotte
<raphael.melotte@gmail.com> wrote:
> Of course ! I forgot the touchpad actually had an lcd. It will be so great
> to be able to have some of those displayed right below the keyboard ! :-)
> I just saw the power button that's connected to the STM32F072 when looking
> for something else.
> If I got it right, PCB1 receives the CPU card and powers PCB2

 nope.  PCB3 powers PCB2, which (through the STM32F) controls the
Battery / Power IC on PCB3, through which power to PCB1 is controlled.

 yes it literally has to be that complex because EOMA68 power is
"OTG-like" i.e. may be *TWO-WAY*.  so the STM32F072 is responsible for
monitoring (through I2C in communication with the Battery / Power IC)
what is going on, also receives notification about power provision
from the EOMA68 Computer Card, and makes decisions whether to put the
Power IC into "OTG Host" or "OTG Client" power modes.

 look up the datasheet on the bq24193 for details.

> which contains
> the STM32F072. Does that mean that a CPU card have to be plugged in in order
> for the STM32F072 to be powered ?

 incorrect.  the STM32F072 is powered continuously  it can never be
powered off (short of opening up the laptop case and physically
disconnecting the battery).

 l.