On 17 Jun 2005 18:35:37 -0700, "Adam Kumpf" <akumpf@gmail.com> wrote:

>Hello,
>
>  I have done some work with Bluetooth modules in the past and have
>connected them to microcontrollers.  However, I am still unclear as to
>what the best module for my applications is.  My main point of
>confusion lies in whether or not a "profile stack" is needed for simple
>data connections.
>
>  For example, I can purchase a $70 module with built in SPP (Serial
>Port Profile) or a $60 module without it.  With the $70 module, hook-up
>is fairly straigh forward.  Just talk to the module over UART/Serial.
>If, however, I go with the cheaper module, how much more work do I have
>to do in the microcontroller to talk to the module?  I'm sure this is
>somewhat module-specific, but in general, how necessary is the "profile
>stack"?  Is it worth the extra $10?
>
>Thank you very much for your comments.

Unless you want to use these modules in huge quantities, $10 is
peanuts to pay for the software stack. Also remember that the
production cost for the manufacturer is essentially 0 for this
software over time. So over time and with the competition one would
expect  they would drop this extra $10.
Just for interest sake, which modules are you considering ?

Regards
  Anton Erasmus

Thanks so much for the reply.

It sounds like $10 is a pretty small price to pay for greatly
simplifying the design of a proof-of-concept prototype.  The time and
cost required to implement my own HCI, L2CAP, and RFCOMM for a
bluetooth project is probably not worth it unless I end up wanting to
produce millions of these gadgets.

Your input was very helpful!

Thanks again,
  Adam
kumpf@mit.edu

Hello,

>  I have done some work with Bluetooth modules in the past and have
> connected them to microcontrollers.  However, I am still unclear as to
> what the best module for my applications is.  My main point of
> confusion lies in whether or not a "profile stack" is needed for simple
> data connections.

depends if it is a private project or a commercial project. And on the 
amount of pieces you want to produce. If it is commercial, you need a 
Bluetooth certification for your developed parts (Bluetooth stack), which is 
not cheap. Also a lot interop test are needed, if you want to be compatible. 
You already have an Bluetooth tester (Air Sniffer, HCI decoder...) ? Most 
important, also take into account the time (and amount of people) needed to 
write such a stack.

If private project, you can just take the modules, create a ACL connection 
and transfer some data. But this way is not compatible to anything else !

Perhaps, to make your decision easier, download the Bluetooth Core Spec. and 
have a look at chapters HCI, L2CAP, RFCOMM. All these are needed to 
implement your Serial Port Profile...

If yu have further questions you can contact me directly via email !

Regards,

        Martin

Hello,

  I have done some work with Bluetooth modules in the past and have
connected them to microcontrollers.  However, I am still unclear as to
what the best module for my applications is.  My main point of
confusion lies in whether or not a "profile stack" is needed for simple
data connections.

  For example, I can purchase a $70 module with built in SPP (Serial
Port Profile) or a $60 module without it.  With the $70 module, hook-up
is fairly straigh forward.  Just talk to the module over UART/Serial.
If, however, I go with the cheaper module, how much more work do I have
to do in the microcontroller to talk to the module?  I'm sure this is
somewhat module-specific, but in general, how necessary is the "profile
stack"?  Is it worth the extra $10?

Thank you very much for your comments.

Best Regards,
  Adam Kumpf
kumpf@mit.edu

Here are the two modules for comparison:

  http://www.mangocommerce.com/btdesigner/department.cfm?dcode=74

(look at the 2nd module <EYMF2CAMM-XX (with Antenna)> and the 6th
module <EYMF2CAMM (UART)>)

Thanks again. :)