[Android] Converting a brick into a phone

Steve Mosher steve at openmoko.com
Fri Dec 12 04:06:39 CET 2008

The Buzz is introduced into the Neo mic. ( Rf enters the mixer, and you 
will see a ripple on the DC coming out to the mic) consequently the far 
end of the call may hear a buzz.

There are two potential fixes: The rework Joerg is drafting ( adding a 
CAP) smooths the ripple and theoretically attenuates the buzz. I think 
you may see some loss in mic sensitivity so a minor adjustment to the 
mic sensitivity ( via ALSA states) may be in order.

Another fix would be to address the root cause and prevent the RF
from entering the mixer. This change is more substantial and requires a
layout change. It would involve adding some beads, changing the mic,
and minor mechanical changes to the case.

My preferred path is to test out the simple fix detailed in Joergs
document as that fix can easily be applied ( the theory goes) to devices
in the field.

Vasco Névoa wrote:
> I'm kinda confused here... is this "buzz issue" the one where the  
> caller (not the neo) hears the GSM buzzing? The one that has a SOP  
> repair paper with the "Big C"?... or is it something else?
> Citando Michel <michel at xternal.nl>:
>> Steve Mosher wrote:
>> Hi Steve,
>>>   A list on the wiki of all severe problems and the end user details
>>> would be great, especially for future reference. Some of the problems,
>>> like Buzz, 1024 (recamp) seem to happen to some people and not others.
>>> I never had the buzz problem, go figure.
>> I've created the page.
>>> 1. problems:  WSOD, recamp, Buzz, echo  ( insert gripe)
>>> 2. End user data:
>>>     a. email (optional)
>>>     b. Date code on phone ( under battery)
>>>     c.  s/n
>>>      d. p/n
>>>     e carrier.
>>>     f. 900Mhz or 850?
>>>     g distro  etc...
>> The page links from
>> http://wiki.openmoko.org/wiki/Neo_FreeRunner_Hardware_Issues#Poor_Audio_Quality
>> And you can find it here:
>> http://wiki.openmoko.org/wiki/Buzz_or_not
>> Please ad fields if necessary
>>> anything else? It might be nice to know what band the phone is operating
>>> on ( 900/1800/1900) if that's possible.
>> Tell me how I can find that info on the phone :)
>>> Steve
>> Regards,
>> Michel
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