Re: Bluetooth setup

Hi,

On Thursday 09 September 2004 23:56, Guylhem Aznar wrote:
>  - where did you get the modulew ith integrated antenna? I think the
I bought several of them via a german distributor frm mitsumi. Since i had a 
bluetooth project in a german computer magazine, you can buy them in Berlin 
from Segor (www.segor.de).

>  - regarding high data rates and resistors inducted unreliabilty - did
>    you test that idea cooling the resistors with say liquid nitrogen
>    spay? According to Johnson theory, the resistor's heat should be the
>    source of unreliability (noise). If getting them cold fixes the problem,
This is a joke, isn't it? Serial resistors combined with a capacitance (which 
cannot be 100% avoided) limits the frequency. This is how simple low-pass 
filters are built. The SIMpad uses them to limit the current flowing from 5V 
DECT module control lines to the 3.3V signals of the simpad. The resistors 
limit the current going through the protection diodes in the 3.3V parts. The 
low-pass this setup builds may limit the data rate.

If the restistors were getting hot, something would be seriously wrong inside 
my simpad ...

>    go along and remove them! It should also remove the need of a voltage
>    regulator.
Why that? The SIMpad still provides 5V and the Bluetooth modules still runs t 
3.3V even if you change the resistors.

Till

-- 
Dr.-Ing. Till Harbaum                       Tel.:  +49 721 4998963
BeeCon GmbH                                 Fax:   +49 721 4998962
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