Will the Neo1973 support Dual-SIM with SPST? Re: Using UART/SPI... for swithing 2-8 SIM-cards Re: [Neo1973] Hardware access: additional solder points ; )

[Robert Michel]

Salve Gabriel, *!

Gabriel Ambuehl schrieb am Sonntag, den 19. November 2006 um 16:56h:

> On Sunday 19 November 2006 16:36, Robert Michel wrote:
> > One of the potential would be a software controlled switching of
> > different SIM-cards. AFAIK "Benefon Twin Dual SIM" was the first
> > phone that allows the user to switch between two SIM-cards with
> > the phone GUI.
> 
> Pushing this further, I'd LOVE to see a phone that can use two SIM cards at 
> the SAME time (so I can have two numbers which would be useful for anyone who 
> has both business and private mobile numbers or got screwed with a bad tariff 
> and can't transfer his number right now...). 
> 
> I doubt this is possible but still one can dream ;)

Technicaly it would be no problem but the question would be if
this device will populare enough to be a mass market product.
I could imagine a (open linux) smartphone with a CF-II port and 
a CF-II GSM/GPRS or GSM/UMTS card to buid this - e.g.:
http://www.expansys.com/p.aspx?i=140979&stack=technical&action=open 

First I thought that just one number and a PBX like asterisk on the mobile,
would solve your problem:
with  different profiles and forwarding private calls during worktime
to the mailbox "Hello $callername I'm at work and I will hear
your message until $calender.break.next - when it realy can't
wait press 9 - or leave now your message after the beeep"

But when the phone is off - both - business and private would go
to the same network mailbox.
And second the phone cost will be mixed on the same bill - but
for this, a Dual-SIM could help you ;)

When you are screwed by a bad tariff you could just switch a network
mailbox on "I'm sorry, I have a new number..."


For my friends I prefer to give them a PSTN (voip) number cheaper for them to
call me and forward it to my mobile with asterisk. With a the Neo1973
asterisk will be able to inform me via GPRS (in the background) who is calling.
And asterisk could be used for call backs so for your monthly billing of your
mobile would be only business calls.

But I have a reason to add, why such a dual mobile would be nice:
Using GPRS with a different SIM then the phone calls.




BACK to the near future and let us think what would be possible to
do with the Neo1973:

################################################
#Will the Neo1973 support "dual-SIM" with SPST?#
################################################

This allows to use 2 SIM and switch with the most mobiles on the market
- you need only an adapter like:    www.dual-sim.com/

This pdf explains the ciruit
> http://www.novotechdistribution.com/productinfo/sonyericsson/GSM_GPRS/GM48-47/Application
> Note - Dual SIM connection.pdf 
and the secret is a signal line "Hi=SIM1, Low=SIM2" and an analog
multiplexer NLAS325 (given example by sonyericsson)

   "The NLAS325 is a dual SPST (Single Pole, Single Throw) switch"
   http://www.onsemi.com/pub/Collateral/NLAS325-D.PDF  
   
So when the Neo1973 GSM Hardware and driver support SPST switching,
we could programm the switching in dependences of time and localisation
and no hardwarehacking would be neccessery, just to by such an adapter
for 10€.

Further hacking - with the signalisation of Hi and Low and a free
access to programm it would it also possible to build a small circuit
for _4_ (6 or 8) SIM cards - HIGH and LOW would be used for signaling :))
And no I/O solderpoint would be used/blocked/wasted for such a muti-card
switching :))


So it would be great, when the phone GSM software and hardware would
support DUAL-SIM ;)
And Sean, please remember that free (just one) PIC (or/and I2C)
bus(es) for sensors/interfaces would be great ;)

Greetings,
rob