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Subject: Re: AW: JB not starting with remote pin connected ?
From: sophana (
Date: 2004-06-23 wrote:

>>>I'm running with 9600 Baud (JB Studio).
>>>How is it possible to transmit with different Baud rates ?????
>>simply change the serial bitrate in the rockbox serial init.
>Serial init means, the Settings or some init inside the Rockbox ?
>As I know, the default is 9600Bd, that is also used with the original Archos
>Why did you change the default ?
>Your remote control is not anymore compatible with JB's with original SW,
>isn't it ?

there are 2 reasons for the serial bitrate change.
First It is related to my implementation for the unilink protocol.
In the unilink protocol, during the idle phases the data goes high and
low during 8ms each.
The master can talk only during the data low phases so I have to listen
to the master.
During the data high phase I am guarenteed that the master won't talk so
I can poll the rockbox by sending a polling char then wait for a
response as long as the data remains high (8ms).
if I want to send 10 chars, it takes about 10ms at 9600b/s. which is too

The second reason is that the software tx patch does poll the timer
during transmission, and I have to transmit inside the rx interrupt. So
the interrupt does last a long as the transmission (blocking other
The faster I transmit, the least time is spent inside the interrupt.

I should have used 57600 b/s but I had a problem (don't know where). It
does work at 19200 that's why I did not change.

Yes it is no more compatible with the standard remote that I don't own,
even if standard remote codes are still supported.
Just a matter of initialization.

Page was last modified "Jan 10 2012" The Rockbox Crew