Rockbox.org home
release
dev builds
extras
themes manual
wiki
device status forums
mailing lists
IRC bugs
patches
dev guide



Rockbox mail archive

Subject: Re: ANNOUNCE: Rockbox emulates M-Bus car CD changer (Alpine and OEM)
From: [IDC]Dragon (idc-dragon_at_gmx.de)
Date: 2004-02-13


> For the sony s-link it uses variable length pulses:
>
> http://www.undeadscientist.com/slink/encoding.html
>
> might still be possible to hack with the uart. But the BIG problem is that
> there is an uncertainty on the last bit value for each byte received. So
> it does not seems easily feasible.

You could use the UART at high baudrate to just find the falling edges
(getting a framing error a byte time after it) and use that for your decoding.

> Is it possible to program a 600us timer interrupt to sample the pin after
> the first falling edge?

Yes, you can do that.

A general thing: most CD changer protocols require more than one line for
their communication. A naked Archos (without external uC addon) can't handle
that. I was "lucky" that Alpine uses only one pin (bidirectionally), and that
the levels are OK.

Jörg

-- 
GMX ProMail (250 MB Mailbox, 50 FreeSMS, Virenschutz, 2,99 EUR/Monat...)
jetzt 3 Monate GRATIS + 3x DER SPIEGEL +++ http://www.gmx.net/derspiegel +++

_______________________________________________ http://cool.haxx.se/mailman/listinfo/rockbox



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