[Arm-netbook] Handheld Games Console

[Luke Kenneth Casson Leighton]

On Tue, Sep 22, 2015 at 7:38 PM, GaCuest <gacuest at gmail.com> wrote:
> Hello everyone,
> I updated the block diagram. I would appreciate if someone can review it.
>
> http://rhombus-tech.net/community_ideas/games_console/news/pcb_block_diagram_22sep2015/

 ok so you liked the idea of being able to make a games controller
from the same PCB, then? :)  it would be really simple, a piece of
plastic and a USB connector - done!

 page 27:
 http://hands.com/~lkcl/eoma/kde_tablet/CM108_DataSheet_v1.6.pdf

 i don't see a need for an EINT to the CM108AH.

 ah, i see what it is:  the EINT goes directly to the Audio Jack.
it's the physical audio socket which has a "connection" which is
broken/made by the physical insertion of a jack.  that, in software,
you would then notice.

 actually what i've done in the hardware circuits i've made, is,
although yes there is a connection there, i added in a resistor bridge
into the circuit to bring the volume down when speakers are engaged.
the CM108AH "normally" would drive the headphones (directly), but in
"speaker" mode the L / R audio goes first to the headphones (where
insertion of the jack would make it "cut out"), and from there (if no
jack) it goes to the resistor-divider bridge to drop the voltage to
1/10th of its level, and *that* is fed into the TDA2822(s).

 so actually, in the circuit that i have done, strictly speaking the
EINT headphone is totally irrelevant... i just added it "just in
case", also to be able to do user-alerts.

l.