[Fwd: Re: [Discuss-gnuradio] Example of DMR receiver]

[John Gumb]

http://algoram.com/dcc2014/AMBE_Exposed.pdf

provides some interesting background to the intellectual property issues
with DMR.

The following is some info on the AMBE-3000 chip which might be of
interest/use to someone and a link selling that chip on a USB stick for
$120 (thumbdv)...

I think I'll crack on with my CW.

Codec2 and FreeDV at least provide some hope.

John
G4RDC
-------- Forwarded Message --------
From: John D. Hays <jo...@hays.org>
To: Veijo Arponen <oh3...@gmail.com>
Cc: discuss-...@gnu.org
Subject: Re: [Discuss-gnuradio] Example of DMR receiver
Date: Mon, 26 Jan 2015 10:03:20 -0800

Veijo,


https://github.com/argilo/gr-dsd


Be advised that mbelib may not be legal to use, hence the anonymity of
the authors.


This ambiguity could be eliminated if someone created a block to use an
AMBE-3000 device.


One source of AMBE devices is
http://nwdigitalradio.com/thumbdv-and-dv3000-resource-page (I am
affiliated with this company).

Talking to the AMBE-3000 devices listed is pretty straightforward,
should someone be inclined.


Open the device as a serial port at 230.4 kbps.


It's a simple packet interface and every packet has a reply.


Send a reset packet hex 61 00 01 00 33 at program startup


Then query for model number packet with hex 61 00 01 00 30 and
look for AMBE3000 in reply


Set D-STAR mode with 61 00 0c 00 0a 01 30 07 63 40 00 00 00 00
00 00 48
Set Yaesu, P25 , DMR, etc. HR mode with 61 00 0c 00 0a 04 31 07
54 24 00 00 00 00 00 6F 48
(See page 83 of AMBE-3000 manual -- link below)


From there, you send in audio 16-bit linear PCM data sampled at
8 kHz in packets and it sends out AMBE in packets. (You can also
use 8-bit ulaw/alaw but the PCM is better quality)


Audio header is 61 01 42 02 00 A0


Or send in AMBE packets and receive audio packets.


AMBE header is 61 00 0B 01 01 48


Pretty much it, just need to frame packet data based on the
packet protocol.


The manual is at http://www.dvsinc.com/manuals/AMBE-3000_manual.pdf --
see Chapter 6. Current software uses the non-parity field version, but
you are free to use either.





On Mon, Jan 26, 2015 at 7:37 AM, Veijo Arponen <oh3...@gmail.com> wrote:
Hello,


My first touch to the Gnu Radio happened this weekend. I managed
to listen a local FM repeater but building a DMR receiver was
too tough.


Please, could someone send me a simple working DMR receiver file
(*.grc) which has a DSD block.


Thanks advanced


73 de Veijo OH3NFC


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John D. Hays
K7VE


PO Box 1223, Edmonds, WA 98020-1223



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