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Subject: Re: sony cd changer emulation almost finished
From: sophana (
Date: 2004-06-01 wrote:

>>I have 6 buttons of the HU mapped to the 6 buttons of my archos. Simple
>>isn't it?
>>So the protocol and implementation is very very simple.
>>I have added 4 more actions:
>>key release (for key repeat implementation)
>>pause (when switching to tuner)
>>resume (when switching from tuner)
>>and power off (when switching off the HU)
>You added, that additional actions to the rockbox SW, right ?
>Is there a plan to integrate that features to the main path development of
>Rockbox ?
>Talking in a general way of implementation into Rockbox, how could these
>functions be accessed (maybe via extended remote interface) ?
Yes I did. It is based on the software Tx patch, and is quite clean.
non polling codes are error filtered like standard remote codes.
key repeat is also implemented quite easily.
My patch for recent rockbox cvs version is available on my site. Feel
free to get what you want there.

>>the status display is also very simple: I display exactly the same than on
>>the archos lcd (scrolling included).
>>I dynamically change the displayed line according to the cursor position.
>>I also transmit track number and elapsed time separatly.
>So the Unilink protocol enables you sending that data to the HU ?
Yes, I had lot of problems in the begining trying to display more than 8
chars. The HU should be able to display up to 48 chars in cd-text mode
and 16 chars in md-mode (managing the scroll by itself).
Finally rockbox does manage the scrolling better...
I still can switch from HU timing display to rockbox text display.
It now works reliably.

>My Panasonic CDC simulator project isn't able to do that, because the
>protocol itself doesn't contain the possibility of any text sending :-((
So my approach won't be possible, because you won't have the necessary
feedback to navigate through rockbox features.
Too bad.
Are you sure there is no extension to the protocol for text display?

>>There is only one poll code, and the rockbox decides what to update by
>>having a header.
>Aahh, some kind of "ping-pong" protocol....
Yes. To manage the half duplex serial pin, the rockbox is polled (every
16ms in my case)

>>I have a power transistor missing for implementing power control from the
>>haven't modded my archos yet for auto power-on. Hope it won't be too
>There were several discussions about that some weeks ago, and that power on
>pulse thing is definetly not working on all JB devices !
>Maybe you should think in shortcutting the JB's OFF key with that
>transistor, that would be electrically the same behaviour as pressing the
yes the dc power pulse does not work for players.
Yesterday, I opened my box, but did not find any wire connecting the
'ON' button. I have to unmount the LCD to have access to the button
switch, but I have scratched one screw, so I can't. I will have to cut
the screw.

Too bad players cannot be flashed yet. because I can see there is a
flash in it.

That would solve the start problem.



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