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Subject: Re: external commands

Re: external commands

From: [IDC]Dragon <idc-dragon_at_gmx.de>
Date: Thu, 13 May 2004 11:18:10 +0200 (MEST)

> I like the way it is defined, with a few tiny extensions:
>
> [IDC]Dragon wrote:
> > CD select buttons:
> > - 0xA0-0xA5 button n (1-6)
> > - 0xA6-0xAF reserved
>
> better (my head unit has got 10 direct disc buttons):
> - 0xA0-0xA9 button n (1-10)
> - 0xAA-0xAF reserved

That's what these "reserved" were for... ;-)

> > Inquiry commandos:
> > - 0xB0 give play status: state (changing, etc) (return payload: 2 byte
> > flags, tbd)
> > - 0xB1 give disk status: #of tracks (return payload: 16 Bit little
> endian)
> > - 0xB2 give current track # (return payload: 16 Bit little endian)
> > - 0xB3 give current track time (return payload: seconds as 16 Bit little
> > endian)
>
> still missing:
> - 0xB4 give track title (return payload tbd)
> - 0xB5 give artist name
> - 0xB6 give album title
> - 0xB7-0xBF reserved

Taking some more, eh? Well, that's what they are for. I hope my "grouping"
by the first hex digit holds.

> I'm not sure yet how the "return payload" should be handled for the text
> strings.

The generic response pretty much defines it:
Byte 1: negated command byte
Byte 2: number of chars
Byte 3...n-1: chars
Byte n: Checksum, 8-bit sum of bytes 1 to n-1

Jörg

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Received on 2004-05-13

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