[gta02-core] Calypso's last dance

Dr. H. Nikolaus Schaller hns at computer.org
Thu Jul 23 18:46:03 CEST 2009


Am 23.07.2009 um 11:52 schrieb Álvaro Lopes:

> Werner Almesberger wrote:
>> Furthermore, there is no immediate plan to produce more devices
>> that use the Calypso. So if gta02-core uses the Calypso, it may
>> well be the last time we see this chipset. This of course raises
>> the question how much work we want to put into this, and if we
>> couldn't do something more interesting instead.
>
> I'm sure we all do. From the beginning.
>
>> Until recently, we knew no suitable alternative. However, a few
>> weeks ago, we discovered a very compact 3G module that would fit
>> inside a slightly modified GTA02 case: the GTM501 made by a company
>> called Option.
>>
>> http://www.option.com/en/products/products/modules/gtm501/
>>
>> As far as I can tell, using the GTM501 instead of the Calypso would
>> be relatively easy if we accept that the existing GSM antenna will
>> be a poor fit. Specifically, the necessary changes should be:
>>
>> - addition of a 3.6 V/3 A DC-DC converter
>
> And how are we to get that amount of power ? That's almost 11W. Even  
> at 1.1A we will be unable to charge battery while USB-powered.
>
> Or am I misreading the numbers ?
>
>> So I wouldn't give up on the Calypso just yet, but I will approach
>> Option and see what I can achieve. To clarify our position, I've
>> prepared the "Disclosure Requisites" whitepaper described in my
>> previous posting.
>
> What other baseband chips are found in recent devices ? I see  
> infineon has some, but most look like full SoC.

I think there was already some discussion that an UMTS chipset is too  
expensive.
What about some GPRS module? I think the MC75I was evaluated and in  
consideration for the GTA03.

Nikolaus




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