[arm-allstar] adding a sdr to allstar node

[KD2NFC - Joe]

Ive been on a quest to use a rtlsdr dongle as radio receive with my Baofeng
for transmit. Not sure if its possible yet but I was able to add my rtlsdr
dongle to ASL and call it up on the node or direct dial it from a sip or iax
end point. 

 

Here are instructions:

 

Install the rtl-sdr drivers on the node. I'm using the Arch Linux OS so I do

 

Pacman -S rtl-sdr 

 

I compiled the keenerds version as he have some bells and whistles in his
build but you just install the package.  

 

Add these commands to rc.local, they will setup the loopback and get rtl_sdr
piping audio to the loopback.  Check the frequency (-f ) to whatever you
like, you can 146125000 syntax as well. 

 

modprobe snd-aloop   ; <-put this before asterisk loading

 

rtl_fm  -M fm -f 145640000  -s 30000 -r 12k -g 3.0 | aplay -r 12k -D
default:CARD=Loopback -c 1 -f S16_LE &  ; <-put this after asterisk loads

 

 

create a alsa.conf in /etc/asterisk/

 

add this.

 

[general]

autoanswer=yes

context=local

extensions=s

language=de

input_device=hw:1,1,0

output_device=hw:1,0,1  

 

 

I'm using usbaudio and it works with Simpleusb also but you have to enable
chan_alsa.so in modules.conf

 

Next create a file called console.conf in the /etc/asterisk directory

 

Add this..

 

[default]

input_device = default

output_device = default

autoanswer = yes

context = default

extension = s

callerid = Radio Console KD2NFC <(0049) 123456789>

language = en

overridecontext = no

mohinterpret = default

active = yes

 

 

I can connect with my sip device by adding this to my extentions.conf 

 

[dialplan]

exten => 222,1,Authenticate(1234)    ; use password 1234 to connect or
comment out this and the playback line below, you have to renumber the
order. 

exten => 222,2,Playback(access-granted)

exten => 222,3,Dial(Console/default)

exten => 222,n,Hangup()

 

 

If you add it to a dialplan context setup to work with your node you can get
to it by doing a autopatch. Rpt fun <yournode#> *6222

Or dial 222 with your sip or iax endpoint. Make sure their contexts points
to the dial plan with the extension you added. 

 

Reboot, don't forget to plug the rtl-sdr dongle in. 

 

This could be good to get a signal into the node like noaa weather, or maybe
you just want to monitor another RF repeater local to you on the node. For
now I have it listening to the frequency I have a svxlink node on and that
has some cool propagation alerts I setup and when they fire I can hear it
when I'm all my all star link node. 

 

Cheers.

 

 

 

Joe

Kd2nfc