08/09/2004 21:57:49, Wookey <wookey@aleph1.co.uk> wrote:

>Having just been to a talk extolling the virtues of POE I did think 
'that
>would be nice on balloon' - the only truly international standard 
power
>source. 

Err, scrounging power from a USB port is also quite universal, 
certainly during development. It's one of the best things about 
USB, especially on desktop PCs - vast amounts of 5(ish) volts 
sloshing about. 

>But I wonder how it would fit in with the already numerous power
>options. And it would probably be 2 chips - the ethernet one 
and the POE
>one.

It's not that much extra area, and it's possible that the PoE chip 
could be used as the general purpose high-voltage supply input, 
too. (The PoE spec allows some pretty wide tolerances on the 
voltage seen at the port). Bear in mind that Ethernet also requires 
a huge RJ45 socket (which may contain the magnetics & LEDs, but 
it's still a lot of area. There's also the question of where to put the 
connector - a perennial problem on Balloon -  which side is a user 
likely to want pointing out of their case, if any?

>I do miss ethernet...but USB provides most of the same 
functionality.

CF-card ethernet works very nicely, both wired and wireless, so 
it's easy enough to get your fix. It's notable that neither of the 
commercial customers that I know of want / fit Ethernet except 
during development. 

Steve