[drats_users] Interfacing ICOM RP2C

[Dan Smith]

> I'd like to use D-RATS at my repeaters. What information does D-RATS need to
> work properly for users on the repeater? I guess the plain serial data from
> the DV stream will be enough on the RX side? The RX stream is already
> available by TCP using "dstarmon" on a gateway.

Yeah, just access to the DV data stream (in both directions of course). 
  D-RATS can already use a socket for the connection, so you may be able 
to connect it to dstarmon to monitor traffic.

> What about the TX side? I assume D-RATS will set URCALL on a normal ICOM
> radio using the serial line?

No, D-RATS doesn't know what the radio's configuration is.  The only 
radios it could actually do this on (if it did) are the 91, 92, and 
ID-1.  D-RATS depends on the radio being properly configured before you 
send data.  Since the interface to the radio is just a bare serial 
channel, it has its own framing and multiplexing mechanisms.

> On a standard ICOM G2 gateway the "dsgwd"
> process will interface the RP2C. D-RATS could inject data using UDP Port
> 40000 on localhost (the common way). The first 5 "header" frames are with
> length of 56 Byte containing the URCALL,RPT1,RPT2,MYCALL settings. Then
> digital voice will follow with 27 Byte packets (which could be filled with a
> precoded audio message like "D-RATS communication" :D) containing the serial
> data bits as well. There are several open source tools with the information
> how to construct the frames. I can assist with testing infrastructure.
>
> If this is to much work, there might be some guys building an interface
> between D-RATS and dsgwd.

Yeah, this isn't something I really have time for at the moment, but if 
other people do, that would be great.  I think the proper interface is 
for someone to just open a socket that D-RATS can connect to, which 
provides bi-directional access to the slow-data stream, instead of 
making D-RATS aware of the lower level D-STAR protocol itself.

-- 
Dan Smith
www.danplanet.com
KK7DS