[Arm-netbook] [flying squirrel] TODO list

[luke.leighton]

On Thu, Sep 26, 2013 at 11:16 AM, luke.leighton <luke.leighton at gmail.com> wrote:

> * find out why the AXP209 is randomly shutting off (could be floating reset?)

 *sigh* this turns out to be because (AGAIN) wits-tech did not...
AGAIN ... tell us that they'd made changes which were NOT authorised,
to the EOMA68-A20 CPU Card schematics.

 this time what they've done is wire the 5V (ACIN) directly to the
USB-OTG line of the AXP209.

 *deep breath*.... the consequences of that are that when the device
is being powered by USB-OTG, 5V appears on the EOMA68 5V power lines.

 the consequences of _that_ are that the flying squirrel I/O board
(which has its own AXP209 and a 5V step-up regulator to turn IPSOUT
into a stable 5.0V output) fights with the incoming 5V power... and
loses the moment that the voltage fluctuates by even the smallest
amount (such as the A20 doing anything resembling the slightest amount
of processing).

 if wits-tech had fucking well told me what they were doing i could
have put in a MOSFET or other power regulator on the I/O board to cope
with power-in as well as power-out.

 not entirely sure what to do here, i'll have to think about it.  as
far as testing the flying squirrel is concerned i can get it working
(in a rather painful laborious way) by disconnecting USB-OTG: i've
verified that the CPU Card can in fact be powered by *incoming* 5V
power from the I/O board... i might need to cut one of the micro-usb
cables i have here and remove its 5V line or something.

l.