[Gta04-owner] GT04+FSO+SHR+Debian: Bluetooth, suspend, lock, SHR profile

Dr. H. Nikolaus Schaller hns at goldelico.com
Sat Jan 26 20:14:49 CET 2013


Am 26.01.2013 um 20:04 schrieb arne anka:

>>>> The problem is that we try to document user-space behaviour of two
>>>> kernels developed by two teams on the same Wiki...
>>> 
>>> if i read that correctly, it would mean there are paths fro 3.x too?
>> 
>> I do not exactly understand what you mean.
> 
> from your phrase i thought, there should be the paths of both the 2.6 and the 3.x kernel. simple misunderstanding

Well, on some Wiki pages there is a section "2.6 kernel" and a section "3.x" kernel, but not all of them.

Generally, the 3.x kernels try to hide more explicit controls from the user and make things more automagic.
To start e.g. GPS, just cat </dev/ttyO1. On the older kernel you have to power on and reset the GPS through
GPIOs, enable the antenna voltage through /sys and then open the device file.

> 
> 
>>> gta04:~# hciattach -s 115200 /dev/ttyO0 any 115200 flow && sleep 2
>> 
>> I think you have to use 3 MBit, i.e. 3000000. There have only been some rare boards with 115200. All others have 3 MBit.
>> ..
>> Yes, that looks like bad baudrate.
> 
> and indeed it was.
> thanks!
> 
> i'ver glanced over the messages related to the baud rate in the past, but didn't really get them.
> my understanding was always, that the baudrate is variable in all cases (multiple of 9600 or such a value), kind of the old serial connections, and not, in fact, fixed.

Yes, the /dev/ttyO port is variable in speed (default is 9600). But not the Bluetooth module at the other end.
It has a flash memory where its baudrate is stored. It *can* be changed but there is no need to do that. And
it is pre-initialized to expect 3 MBit/s because that is the maximum speed and allows up to around 2 MBit/s
bluetooth data transfer (if the other Bluetooth end points are capable to do so).

> 
> thanks again and up to the next feat -- getting the bt keyboard working ...

Ok, for a keyboard you won't need 3 MBit/s max. data rate :) But the hci protocol takes care of everything.

Good luck,
Nikolaus



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