RE: [Balloon] Re: Next Balloon

>Having spent half of today reading data, it does look like a very
>fine candidate. (and it's got 4 PWM channels, which I know you
>guys were hankering after, and the interface to FPGAs looks
>exceptionally convenient)

Four PWM's certainly gets my vote...

And I was just about to suggest a bottom side FPGA please, before Steve
mentioned it...

I'd also like to see a 3v3 switcher and a 5v switcher.
This should be configurable to allow the board to work off a single LiPo
cell at 3.6v or a Nicad/Nimh stack of 4 cells at 4.8vish...
Given that most balloons are in battery based products.

Once that’s on board support for charging would be nice.

It doesn’t have to be a full blown charger since chemistry may change
and new battery sizes etc may undermine any design cast in stone.
Is it possible to integrate a micro with access to the right bits of a
charging circuit and leave the implementation open?

It may also be a good idea to add a micro so that the board has a little
more intelligence when in standby. Standby is currently 4mA and may well
be lower on a new design (certainly with lower power RAM). A micro
consuming 1mA would be a gain if it can monitor Battery, or Comm's
connections, or other IO and decide to wake up the "Giant" to do real
work.

On other issues raised to date:
a) I wouldn't want to see any change in the physical size, I want to be
able to "field" replace existing Balloon boards in Hydra systems where
they are in applications that are running out of CPU power.

b) We should stick to the one PCB, one Design, many fit options scenario
as this is easy to manage and seems to have made Balloon more broadly
interesting. However we need to specify a very low cost minimum fit
option to keep hobbyists happy. I'd suggest a target BOM cost of £50
giving a possible selling price of about £150-£200. Lower if possible...


Now for the dose of reality....

Currently Balloon board manufacture of 2.05 is due to stop at Xmas...

It's unlikely that a replacement based on PXA27X will be available in
time to replace it as this is going to take at least 6 months to spin
out and get right through to production (which is about a quarter of the
time it took to get 2.05 out and fully productionised).

If PXA27X is so new we may have trouble getting silicon since as Steve
points out 3G phones will take the lions share of production, it only
takes one too many 3G phone designs based on it to dry up supply of the
few 100 per month that we will need.

Thirdly unless a new source of funding has appeared, TCL are going to
have to "want" this new design since in essence they will be paying for
much of it.... David M?

It's possible that the PXA27X is a step too far. Has Linux ported to it
yet?
Are all the device drivers available? (Nick?)

Thoughts?

David.