Setting up Ardop on an Raspberry Pi

This instructions assumes that you have already downloaded piardopc to your Pi, have an usb sound card and some piece of software that uses Ardop to send and receive data over the air. Pat and ARIM are both excellent programs.

Info from the maker here.

http://www.cantab.net/users/john.wiseman/Documents/ARDOPC.html

http://www.cantab.net/users/john.wiseman/Downloads/Beta/ARDOPC.txt

Open a terminal, if connected to an monitor, or SSH into the Pi. Find the Pi's IP address by using Fing on an android phone or tablet connected to the same nettwork. If using Juice ( or other terminal amulator/SSH app) on your phone use Screen to be able to run multiple processes in one terminal.

Navigate to the folder where you downloaded piardopc. Make it executable by running the command " sudo chmod 755 piardopc "

Connect an USB sound card and run the command " arecord -l "

This gives me the output:

**** List of CAPTURE Hardware Devices ****

card 1: Set [C-Media USB Headphone Set], device 0: USB Audio [USB Audio]

Subdevices: 1/1

Subdevice #0: subdevice #0

Remember the card number and navigate to your home folder and open or create the file .asoundrc. " nano .asoundrc " The . in front of the file name is important.

This file should contain the following lines. Just copy and paste, and replace the card number with the output number from arecord.

pcm.ARDOP {

type rate

slave {

pcm "plughw:1,0"

rate 48000

}

}

CTRL+o saves the file and CTRL+x exits nano.

Start ardop with PTT on GPIO 17 by navigating to the folder with piardopc and running the command " ./piardopc -p gpio "

If everything is working properly you will see something like this in the terminal.

pi@raspberrypi:~ $ ./piardopc -p gpio

ARDOPC Version 1.0.2.5l-BPQ

GPIO interface for PTT available

Using GPIO pin 17 for PTT

ARDOPC listening on port 8515

getReadDevices

Card 0, ID `ALSA', name `bcm2835 ALSA'

Card 1, ID `Set', name `C-Media USB Headphone Set'

Device 0, ID `USB Audio', name `USB Audio', 1 subdevices (1 available)

1 channel,

sampling rate 44100..48000 Hz

hw:1,0 USB Audio(C-Media USB Headphone Set)

getWriteDevices

Card 0, ID `ALSA', name `bcm2835 ALSA'

Device 0, ID `bcm2835 ALSA', name `bcm2835 ALSA', 7 subdevices (7 available)

1..2 channels,

sampling rate 8000..48000 Hz

hw:0,0 bcm2835 ALSA(bcm2835 ALSA)

Device 1, ID `bcm2835 ALSA', name `bcm2835 IEC958/HDMI', 1 subdevices (1 available)

2 channels,

sampling rate 44100..48000 Hz

hw:0,1 bcm2835 IEC958/HDMI(bcm2835 ALSA)

Card 1, ID `Set', name `C-Media USB Headphone Set'

Device 0, ID `USB Audio', name `USB Audio', 1 subdevices (1 available)

2 channels,

sampling rate 44100..48000 Hz

hw:1,0 USB Audio(C-Media USB Headphone Set)

Opening Playback Device ARDOP Rate 12000

Playback Buffer Size 65536

Opening Capture Device ARDOP Rate 12000

ARDOPC listening on port 8515

Input peaks = 0, 322

Input peaks = 0, 321

Input peaks = 0, 319

Connect you radio and make level adjustments.

Adjust RX level until Input peaks show something around +/-20000

More about this here http://www.cantab.net/users/john.wiseman/Downloads/Beta/ARDOPC.txt

You can use alsamixer from terminal to adjust volumes.

Next use your favorite client and send some data to adjust TX level according to to your radios instructions.

Thats about it.

Good luck.