On Tue, 30 Dec 2008 06:08:57 +1100, Franc Zabkar
wrote in
:

On Sun, 28 Dec 2008 08:18:55 -0800, John Navas
put finger to keyboard and composed:

True. But off topic. Usenet is reserved for uninformed speculation and
ranting, not facts. Please be more careful in the future.

Here are the facts:

USB "Battery Charging Specification":
http://www.usb.org/developers/devcla...arging_1_0.zip

A USB charger does not require any smart electronics, only a shorting
wire (R 200 ohms) between the D+ and D- pins. The 5th ID pin must
remain unconnected.

This means that one really only needs 4 wires, so any implementation
that uses a 4-pin connector would be compliant from an electrical
point of view.

If we assume that a Blackberry charger is wired as per the above
standard, then it should be able charge any compliant phone, camera,
etc.

Sorry, but that's your leap of faith, not what the spec says.

However, it won't charge a Motorola phone because the latter
expects to see a particular non-standard voltage on the ID pin.

It's standard, and not a voltage.

OTOH, a non-standard Motorola charger which places 1 volt on the ID
pin will not upset a compliant USB device (eg a Blackberry ?) because
such a device expects this pin to be either grounded or not grounded.
The device doesn't care whether the "not grounded" state is at 1V or
2V or whatever, it only cares that it is not 0V.

Those are your contentions, not what the spec says.

--
Very best wishes for the holiday season and for the coming new year,
John