Bluetooth to 2410 Wiring

[Ian Stirling]

Harald Welte wrote:
> Hi Wally!
> 
> On Thu, Jul 26, 2007 at 10:48:59PM -0400, Wally Ritchie wrote:
> 
>>>I'll look into that issue, though.  If we still can make it, we will.
>>>But I'm not very confident.
>>>
>>
>>Thanks for looking. There are a total of 8 flexible PIO's on the on BT module
>>of which you are using two. 
> 
> 
> I know.  The problem is that the bluetooth module was put on a FPC, and
> that FPC has only a fixed (minimal) number of lines.   The entire design
> was done by the hardware team which was not really under our control at
> that time, so our influcence (and actual knowledge of what was going on)
> was very minimal.

I need to do more reading on the CSR hardware in the bluetooth module.

Having said that.
As I understand, the chip is in principle quite flexible, having FLASH, 
and ROM versions, as well as a flexible development environment.

I do not of course know what the price delta is between FLASH and ROM 
parts, or what the initial cost would be for a ROM part.

If it is possible to reroute one of the FPC lines to an interrupt 
capable pin of course.

Find an interrupt device that can be wire-ORed with the wakeup line - 
perhaps the GSM wake?

Configure(if possible) the bluetooth module for weak pullup/down.

Alter the firmware in the module so that it can be switched to 'suspend' 
mode, which changes the meaning of one of the IOs on the FPC to be wakeup.

If you want woken on GSM interrupts only, turn the bluetooth module off 
first. (it cannot have its power turned off, as otherwise it will 
violate the input voltage conditions with 0V VCC) however the power use 
is really low in this mode - fractions of a milliwatt.

If you want woken only on bluetooth wake interrupts, do the same with 
the GSM module.

If you want to put it to sleep totally, and not wake on either, power 
both down.

This could (potentially) be one additional trace from the existing GPIO 
to an EINT pin, and software changes on the module.


To expand more on use-cases.

I want to wake on keypresses on an external keyboard.
To wake on calls from an external bluetooth modem.
To wake on coming into range of a known bluetooth device.
   Getting into car, and having phone start logging your journey 
automatically)
   Coming into range while wearing a BT headset, and having the phone 
notify you of missed calls.