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Datasheet: UDRCDS


Important: Use only Compass Linux images and dstarrepeater packages.  They contain support specific to the UDRC™. Source is available for review on GitHub.

During initial startup do not modify the basic Raspberry Pi setup. For example, do not overclock the Raspberry Pi, it is not needed as performance is more than adequate, and doing so can change clocking values on busses used by the UDRC™ causing it to either not function or be unstable.  If you make any changes not listed in these instructions, and your UDRC™ does not function, return to the original settings.

Please verify your DR-1X has recent firmware installed.  For analog and D-STAR with no Fusion Digital, the UDRC™ has been tested against versions 1.00m and 1.00t (no further testing will be performed on the 1.00 series firmware).  For D-STAR, Fusion Digital, and analog, the UDRC™ has been tested on 1.10D, 1.10J and 1.10Q.  We recommend that you upgrade to 1.10 series firmware.

Mount your UDRC™ on a Raspberry Pi 2 or 3

Note: Raspberry Pi 3 Addendum

ARMv6 Raspberry Pis are not supported.  This includes the A/A+, Zero, Pi 1 B/B+, and Compute Module.

Make sure the pins are properly aligned and use the supplied standoffs to support the board above the HDMI port.

Universal Digital Radio Controller Universal Digital Radio Controller


A video tutorial is available on YouTube 

ircDDB Registration

Now is a good time to register a unique callsign for your repeater at  In the United States this needs to be a club callsign, in other countries a secondary callsign is necessary.  If you want to use your personal call sign, you will be able to run the repeater and perform linking to repeaters and reflectors, but will be unable to do callsign routing including STARnet Digital groups. If you already have an ircddbgateway registered, you can just add this repeater to it via configuration.

Create the Boot Image

  1. Obtain a high quality microSD card.  A Class-10 card of 8GB or more is recommended.
  2. Download a Compass Linux image from
  3. The 'lite' version is without a GUI and will require hand editing of the dstarrepeater configuration file.  The full version has graphic configuration tools for those new to setting up dstarrepeater and ircddbgateway.
  4. Unzip and copy the uncompressed image to the SD card using the procedure outlined on the Raspberry Pi site.

Boot for the First Time

  1. Place the microSD card in the Raspberry Pi.
  2. Attach a monitor and keyboard/mouse to the Raspberry Pi
  3. Attach Ethernet via the RJ-45 jack to your network.
  4. Apply power via one of these methods
    • Using the microUSB port next to the HDMI port (good if you are not at the repeater site)
    • Through the 15-Pin connector while attached to the DR-1X repeater (Power down the repeater while installing the supplied 15-Pin cable)
  5. Allow the Raspberry Pi to boot up
  6. Login  (User: pi, Password: raspberry)
  7. From a terminal command line, verify that the UDRC™ is recognized by typing the command aplay -l (that's a lowercase l) and observe that udrc is listed as a card.  If you do not see it listed, power down and remount the UDRC™.
  8. Perform any Linux configuration specific to your installation, e.g. assign specific network addresses, install favorite tools, etc. (This is beyond the scope of NW Digital Radio support, please use Linux support resources for assistance.)
    Note: DO NOT RUN raspi-update - it will break your install
  9. You may wish to edit the /etc/hosts file and add reference to the hostname, for example if you keep the default 'compass' hostname, add a line compass
    If you want to change the computer hostname use the command:
    sudo raspi-config
    Then select "Advanced Options" -> "Hostname" and follow the instructions.  It will update the hostname for your Raspberry Pi and will make the change in /etc/hosts
  10. To preset the pins and levels on the UDRC™ we provide a script. Execute the following:
    curl -L -s | sudo sh
    (the 'pipe' or | is usually above the \ key on most keyboards -- if you want to see what the script does, leave off  '| sudo sh')
  11. Optionally disable the internal sound chip by editing /boot/config.txt and commenting out this line (recommended unless you need it for something else):
  12. To gracefully shutdown the Raspberry Pi, you may use the command:
    sudo halt

Install Applications

You may install any mix of GUI and non-GUI versions of the repeater and gateway software. Use the following commands on the command line.

For the GUI tools:

sudo apt-get update
sudo apt-get upgrade
sudo apt-get install dstarrepeater ircddbgateway

If you want a set of desktop Icons to start the GUI applications, see: 

and download file icons.tgz to the 'pi' user home directory /home/pi then

tar -xzvf icons.tgz

For the non-GUI tools:

sudo apt-get update
sudo apt-get upgrade
sudo apt-get install dstarrepeaterd ircddbgatewayd 

If you are running ircddbgateway on another computer, there is no need to install it on the Pi. You will configure dstarrepeater to access the ircddbgateway.

Prepare the DR-1X

The repeater must be set for remote mode.

Be sure to use CTCSS on RX/TX in analog, avoid 100.0 Hz as that can false on a GMSK signal.  

User radios should use CTCSS or DCS squelch on TX and RX.  Also, recommend to your users to activate BCLO (Busy Channel Lock Out) on their radios to help avoid stepping on transmissions in a different mode.

Configuration of dstarrepeater

Download the seed file for the dstarrepeater

sudo curl -L -s -o /etc/opendv/dstarrepeater_1

If using the GUI install, you can edit the file with:

sudo -E dstarrepeaterconfig 1

If non-GUI, use an editor like nano or vi to edit, e.g.

sudo nano /etc/opendv/dstarrepeater_1

You will need to change the repeater callsign and gateway callsign to your system.  If you are doing a 70cm repeater these are the only settings that need changed for initial configuration.  Only adjust other settings if you understand their effect.

If you are using a 2 meter configuration, you will need to change the Sound Card Modem RX to 0 or not inverted.

The repeater will switch to D-STAR upon receiving D-STAR traffic and return to the configuration set for the UDRC™ (serialConfig in dstarrepeater_1)

Configuration Choices are:

  1. Auto RX / Fixed FM TX
  2. Auto RX / Auto TX  (Default in the seed file)
  3. Fusion Digital Fixed RX / Fusion Digital Fixed TX
  4. Fixed FM RX / Fixed FM TX
    (Use this if you are on DR-1X firmware 1.00*)
  5. Is used for simplex access points (hotspots) and non DR-1X repeaters attached to the Mini DIN-6 connector

Starting dstarrepeater

If you powered the Raspberry Pi using the micro USB port, shutdown and remove the USB cable.

Make sure the UDRC™ is connected to the DR-1X using the provided 15 pin cable.  This should power up the Raspberry Pi.

NOTE: Many standard VGA Cables do not have all of the pins wired and will not work!

Login to the Raspberry Pi and issue the command:

sudo systemctl start dstarrepeaterd@1

The repeater should now repeat D-STAR signals received on the repeater's input. Test by keying up and watching the D-STAR radio's display.

The code gives preference to local traffic over D-STAR network traffic, regardless of mode.
If you want to run WIRES-X use a separate node radio attached to the HRI-200.  You cannot use the HD-15 and mini DIN-10 at the same time.

If you want to see a GUI, run the commands:

sudo systemctl stop dstarrepeaterd@1
sudo dstarrepeater 1

Logs for troubleshooting are at /var/log/opendv

If you want the dstarrepeaterd daemon to start on reboot, issue the command:

sudo systemctl enable dstarrepeaterd@1

A video of hints for management of the daemon.


Since there are no special instructions for ircDDBGateway for the UDRC™, please refer to the documentation in the files section of the Yahoo Group ircDDBGateway If you would like a web based dashboard for ircDDBGateway, check out the real time dashboard at ircNodeDashboard

Visit our quick startup Wiki page for ircDDBGateway.


  1. Did you follow the this Wiki exactly? Please review line by line.
  2. Make sure you didn't do anything to the Linux install, not listed in the Wiki (e.g. overclocking or other modifications)
  3. Are you using a Raspberry Pi 3 or 2? If a Raspberry Pi 3 -- review
  4. Which firmware revision is the repeater controller using? If not the latest 1.00 version, please update.
  5. Is the repeater set to remote mode?
  6. Is it on 2m or 70cm?  If 2m, note the change you need to make to configuration.
  7. Is the repeater in FM or Narrow FM?  If Narrow FM, you will need to modify the configuration.
  8. Does the repeater key up and repeat in FM mode? What PL are you using? Is PL set on both receive and transmit?
  9. Are you running dstarrepeater in GUI mode or daemon mode?  If GUI mode, make sure the daemon is not running in the background.
  10. Next see if the UDRC is receiving and decoding your transmissions. Open a terminal window and type:
    sudo tail -f /var/log/opendv/dstarrepeater_1.log
    (if in GUI, otherwise for the daemon run)
    sudo tail -f /var/log/opendv/dstarrepeaterd_1.log
  11. Key up on D-STAR, do you see header information coming from your transmissions?  If so, then receive should be good.
  12. Do you get a response from the repeater, with the end of transmission beep?  If yes, then your UDRC is functioning with the dstarrepeater program.  If no, then take a second radio and leave it open squelch on the output frequency of the repeater, transmit on D-STAR -- do you hear modem tones?  If so, switch the second FM radio to the input frequency of the repeater and transmit D-STAR, are the tones approximately the same "loudness"?  If not, then the setup is wrong from the alsa settings you loaded.


If you would like a web based dashboard for ircDDBGateway, check out the real time dashboard at  ircNodeDashboard


The DR-1X operates with a controller attached to the HD-15 accessory port or a Yaesu HRI-200 attached to the Mini DIN-10 connector. You cannot operate with both connected at the same time.  If you wish to run D-STAR via the UDRC and WIRES-X on the same repeater, it is necessary to set up a WIRES-X node on the repeater's frequencies.

A WIRES-X node consists of a Microsoft Windows based computer, Yaesu HRI-200, and a radio like the FTM-100DR, with an antenna separate from the repeater.