Power supply for FCDEV3B

[Mychaela Falconia]

Hi DS,

> To use it
> with either DP-L10 or C1xx, I removed the lithium part of the battery,
> and connected the GND and power to where the lithium battery was.
> This way the phones believes there is an actual battery connected.
> Alternatively, I believe since the communication is I2C, one could
> use a microcontroller for the purpose of feeding the appropriate info.

There is no intelligence in Motorola or Pirelli batteries (they are
called "dumb" batteries unlike the one Openmoko made for GTA02), and
certainly no I2C.  Instead there is a thermistor inside the battery
pack connected between the third pin and GND, and nothing more.
Openmoko's GTA02 battery has HDQ on the third pin to communicate with
the "fuel gauge" chip instead of the original thermistor.

Instead the real difficulty with connecting a power supply instead of
a battery to a phone (as opposed to a board like our FCDEV3B made
specifically for development), or connecting either a power supply or
a real battery to a bare phone PCBA without the plastic case, is
mechanical - making a reliable, low-resistance and potentially high
current connection to the battery connector on the phone PCBA.

I may have a need at some point to connect either a power supply or a
real battery (either option would be equally acceptable) to bare (no
plastic case) GTA02 and Pirelli motherboards, and I haven't found a
good solution yet.  But this need is not immediate, just potential at
this point.

M~