Tag: DSTAR

Week 9 – Many Problems

This week, I downloaded a Nextion Display layout created by PD0DIB and modified it to include a system control page and an information page. After trying out the Nextion Driver Installer created by ON7LDS, I could get the screen to display information one time, but after switching pages, the data would disappear. To solve this problem, I looked at the Nextion Driver Installer script and followed most of the steps manually. Doing it this way also allowed me to switch the displayed CPU temperature from celsius to Fahrenheit. This pretty much solved the issues with the display.

In the Nextion Driver Installer Script, I followed this section:

if [ "$ND" = "" ]; then
    echo "+ No NextionDriver found, trying to install one."
    compileer
    $SYSTEMCTL
    $NDSTOP
    $MMDVMSTOP
    killall -q -I MMDVMHost
    killall -9 -q -I MMDVMHost
    if [ "$CHECK" = "PISTAR" ]; then 
        cp $DIR"/mmdvmhost.service.pistar" /usr/local/sbin/mmdvmhost.service
    fi
    if [ "$CHECK" = "JESSIE" ]; then 
        cp $DIR"/mmdvmhost.service.jessie" /lib/systemd/system/mmdvmhost.service
        cp $DIR"/mmdvmhost.timer.jessie" /lib/systemd/system/mmdvmhost.timer
        cp $DIR"/nextion-helper.service.jessie" /lib/systemd/system/nextion-helper.service
        if [ -e /etc/systemd/system/nextion-helper.service ]; then
            echo "+ there is already a link /etc/systemd/system/nextion-helper.service"
            echo "+ I'll leave it like that."
        else
            ln -s /lib/systemd/system/nextion-helper.service /etc/systemd/system/nextion-helper.service 
        fi
    fi
    cp NextionDriver $BINDIR
    echo "+ Check version :"
    NextionDriver -V
    checkversion
    helpfiles
    echo -e "+ NextionDriver installed\n"
    echo -e "+ -----------------------------------------------"
    echo -e "+ We will now start the configuration program ...\n"
    $DIR/NextionDriver_ConvertConfig $CONFIGDIR$CONFIGFILE
    herstart
    exit
fi

Basically all I did was the following:

  1. Stop MMDVMHost with “sudo service mmdvmhost stop”
  2. Download the Nextion Driver from github into the /tmp folder
  3. rpi-rw
cd /tmp
git clone https://github.com/on7lds/NextionDriver.git
cd NextionDriver
  4. Compile the driver by running “make”
  5. Then you should end up with a binary called “NextionDriver”.
  6. Copy the binary into /usr/local/bin with 
    sudo cp NextionDriver /usr/local/bin/NextionDriver
  7. This was all done AFTER running NextionDriverInstaller.sh on its own. So, my installation had all the helper files already installed before I ran through these commands.

Problem 2

The hotspot/repeater doesn’t startup right away like it does at home. I’m guessing this is because of the enterprise WiFi at my University. Sometimes the repeater starts right up and works perfectly and other times it does not work.

Problem 2 Solutions

  1. Create a simple script to reset the WiFi connection on the Pi and create a button on the Nextion Display Layout that would allow me to run this script.
  2. Use the same script, but have it run after the Pi is completely booted and add a line to restart the MMDVMHost service.

Problem 3

I could not always access the PiStar dashboard through the ethernet/crossover cable or through the University’s WiFi. Again sometimes I had no issues and other times it would not connect. At first I thought this was due to having both the ethernet and the WiFi running on the Pi, but after removing the ethernet, I had the same issue. I’m growing more suspicious of the enterprise WiFi. As for it not working over the crossover cable, I believe this is due to the fact that the computer is addressing itself with a self-assigned IP address (a 169 address). The problem appears intermittent.

Problem 3 Solutions

  1. Use the solutions for problem 2 as I believe the two problems may be related.
  2. Create a static IP on the Pi and the Computer for the ethernet connection.
  3. Change the PiStar firewall rule for the dashboard from “Private” to “Public.”

Going Forward

  1. Enable DMR and configure it.
  2. Install the Brandmeister control panel on PiStar.
  3. Program the DMR Radio.
  4. Create a blog post about programming the DSTAR and DMR radios.

I also wanted to create a 3D printed case for this project, however I am not sure I will have enough time to do that, especially with encountering these problems.

Week 7 – Configure DSTAR Mode

First we’ll go turn on the DSTAR digital mode and configure it.

  1. Start by going to your PiStar dashboard in your web browser.
  2. After logging into your dashboard, click on the “Configure” tab.
  3. Next we’ll turn on DSTAR in the MMDVMHost Configuration.
  4. Notice that I also set the RF Hangtime and Net Hangtime to 5 seconds. The hangtime is the amount of time the MMDVM will stay in that mode before allowing other digital mode signals a chance to reach the repeater. RF Hangtime is the amount of time the MMDVM waits after the end of an incoming RF (Radio Frequency) signal. Net Hangtime is the amount of time the MMDVM waits after the end of an incoming network transmission from a distant station.
  5. Click “Apply Changes.”
  6. After the changes are applied, scroll down and you will see a new configuration box named “DSTAR Configuration.” The defaults will look like this:
  7. Here are my settings for DSTAR and I’ll explain them after the photo.

Explanation of Settings

  1. RPT1 Callsign – This is the callsign of the node or repeater with its module letter. B = 70CM / C = 2M
  2. RPT2 Callsign – This is the callsign of the gateway, which in our case will be the same as the repeater, but instead of module “B” it will be “G” for “Gateway.”
  3. Remote Password – This is the password used by the ircDDBRemote application as well as the command-line Remote Control application.
  4. Default Reflector – This is the default reflector that the repeater will connect to. A reflector is like a group chat or conference server for many repeaters to connect to. Note that this can be set to “Startup” or “Manual.” I chose “Manual” because I do not want my repeater to automatically connect to a reflector when the repeater turns on.
  5. APRS HOST – APRS stands for Amateur Packet Reporting System and allows data like GPS coordinates, altitude, speed, etc to be reported to other amateurs. This data can be viewed online at a few sites like https://aprs.fi the “rotate” APRS Host is a round robin server according to http://www.aprs-is.net/aprsservers.aspx
  6. ircDDBGateway Language – Select your language and country code if applicable. I selected “english_(US).”
  7. Time Announcements – If turned on, the hotspot/repeater will announce the time every hour.
  8. Use DPLUS for XRF – I don’t use XRF reflectors, so I left it turned off, but this would allow you to use the DPLUS protocol to connect to XRF Reflectors.

Later this week, I’ll discuss programming your DSTAR radio as well as enabling DMR. I’ll also be adding a Nextion Display to this project and attempting to create my own Nextion Display layout in the Nextion Editor Software.

Week 5 – PiStar Setup Part 2 of 2

In this post I will explain how to update, upgrade, and configure the basic settings for Pi-Star. I will also explain how to register your amateur radio callsign for DSTAR and DMR use.

Part 1 of this post: https://n3tdm.tdmorris.com/week-4-setup-part-1/

First of all, for this project you MUST be a licensed Amateur Radio Operator. In the USA, that means passing a licensing exam and being assigned a callsign from the Federal Communications Commission (FCC). For licensing information check out the American Radio Relay League.

Register your Callsign for Dstar

  1. Follow the instructions to register your own callsign found here: http://www.dstargateway.org/D-Star_Registration.html
  2. After you receive your confirmation email, go to this page to learn how to assign terminal ID’s to your callsign (STEP 1 only). Terminal ID’s are just what they sound like, it’s an identifier for your individual station. If you’re just using one radio, you can typically set a terminal ID of a single space, however we’re setting up a repeater, so you would need the space terminal ID and whatever module you’re using B for 70CM or C for 2M frequencies.
  3. My terminal ID’s look like the following: 
  4. Here is more information on Terminal ID’s: https://wb1gof.dstargateway.org/DStarTerminalIDs.html
  5. After you’ve registered for DSTAR you need to get a CCS7 ID for DMR.

Get a ccs7 id number for DMR / DSTAR

  1. Head over to this site and fill out the form selecting the option for a private callsign and NOT a repeater. I’m going to be setting up a private repeater for experimentation so it won’t be running 24/7.
  2. Once your request is processed, you’ll receive an email containing your CCS7 ID number. Put that in a safe place.

Setup and Configure wifi

In order to configure this, because I had no way of getting the IP address from a headless Raspberry Pi, I connected a crossover cat5e cable between the Pi and a PC so I could connect into it and make adjustments.

That said, I want to first explain how I setup the enterprise WiFi for the Pi to work on Pitt’s wireless network.

    1. I followed the instructions located here: https://gist.github.com/chatchavan/3c58511e3d48f478b0c2
    2. First open a new tab in your browser and go to
      Windows: http://pistar/admin/expert/ssh_access.php
      macOS: http://pistar.local/admin/expert/ssh_access.php
    3. Enter “pi-star” without the quotes for the username and press enter.
    4. Enter “raspberry” for the password without quotes and press enter.
    5. You should be greeted with a screen spelling out PI-STAR.
    6. Now type 
      sudo nano /etc/networking/interfaces
    7. You should see the following screen:
    8. Use the arrow keys to navigate the page and move down to the section that says 
      allow-hotplug wlan1
iface wlan1 inet manual
        wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf
    9. Erase the section above and enter the following: 
      auto wlan1
allow-hotplug wlan1
iface wlan1 inet dhcp
	pre-up wpa_supplicant -B -Dwext -i wlan1 -c/etc/wpa_supplicant/wpa_supplicant.conf
	post-down killall -q wpa_supplicant
    10. Press CTRL+o and press enter, then press CTRL+x to exit the nano editor.
    11. Then go to the Configuration page of your Pi, then to the Expert tab, then click “WiFi” in the “Full Edit” line of editors.
    12. You should see a list of networks (probably just one) after a header of sorts
    13. Make sure the country code following “country=” matches your country code. In the USA it’s “country=US” without quotes.
    14. For the enterprise wifi you need to make a new network in this config file. For WIRELESS-PITTNET at the University of Pittsburgh at Bradford, I used the following settings. In this editor I set up the following network:
    15. Go back to your SSH access page in your browser and do the follow steps.
    16. Enter the following substituting YOUR_PASSWORD with your university email password leave the single quotes around your password. and press enter. 
      echo -n 'YOUR_PASSWORD' | iconv -t utf16le | openssl md4
    17. Next copy the resulting random letters and numbers into the WiFi editor in the other tab after the colon where it says “password=hash:”
    18. Now go back to your SSH editor and clear your history by typing: 
      history -c
    19. Press “Apply Changes” at the bottom of the page beneath the wifi editor.
    20. If you followed these steps correctly your pi should connect to WIRELESS-PITTNET.

Configure Pi-star

  1. In your browser go the main page of your Pi-Star dashboard at:
    Windows: http://pi-star/
    macOS: http://pi-star.local/
  2. You should see the following page:
  3. Start by selecting MMDVMHost and Duplex (repeaters) or Simplex (personal hotspots), then click apply changes.
  4. After the services are restarted, you should see the following page:
  5. I started the configuration process without the actual interface board, keep that in mind. I did not activate any services yet, however I set the hostname, the node callsign, the RX/TX Frequencies, the GPS coordinates, the town (in the format of “city”, “grid locator”, the country, the URL (this can be either a manual URL of the dashboard for the repeater or automatic and will default the QRZ page for the node callsign), the node type (public – anyone can use it / private – only the node callsign can use it), the time zone, and the dashboard language_country code.
  6. You can also setup the firewall if you wish. Private makes it only work within your local network, public will make it work from outside your network provided the correct ports are forwarded on the router.
  7. I left Auto AP on because if the Pi doesn’t/can’t make a network connection, it will create a wifi hotspot of it’s own so you can connect to it and configure the network settings.
  8. I left UPNP turned off. If your router also has UPNP, you can turn this feature on and Pi-Star will configure your router’s firewall to open the necessary ports.

I found a neat little circuit board on eBay that works with MMDVMHost software and is a mini personal repeater on a single board. I thought this would be a great way to demonstrate a repeater without having to bring in multiple radios, a power supply, the computer, etc. So I’m going to use the MMDVM_HS_Dual_Hat. The board on eBay is a cheaper Chinese “clone” of the original board which is pictured below.

Week 3 – DSTAR Repeaters

Last week, I decided to use a software I’ve worked with in the past, called Pi-Star to setup a digital multimode amateur radio repeater. This week I did a bit more research on DSTAR and found some diagrams to hopefully explain things a little better. If you aren’t familiar with what a ham radio repeater does, there is a diagram below.

Basically a repeater listens on one frequency and simultaneously retransmits what it “hears” on another frequency. Typically a repeater is at an elevated location (i.e. a mountain top, tall building, etc), running a high performance antenna system and higher power output.

How does a digital repeater work? It works in much the same way as a regular repeater, however with DSTAR, there is often an internet link via a computer added to the repeater as shown below.

The diagram above is of one digital mode called DSTAR, but most digital modes work similarly in respect to the hardware required. In a DSTAR repeater there is a radio connected to an interface board which is then connected to a computer (usually either a PC or a Raspberry Pi). The computer makes and manages the connections through the internet to other repeaters or reflectors (conference servers). The computer makes these connections based on commands sent over the radio, sent through a remote control application, or sent through a web interface. An example of the Pi-Star web interface for the KC3ESS DSTAR repeater that I help manage is included below.

The dashboard lists the timestamp of the transmission, the target (where the transmission is intended to go), the RPT 1, and RPT 2 callsigns.

The target of a transmission tells the computer what to do, so CQCQCQ means that the transmission is intended for everyone to hear, REF030CL tells the computer to link to reflector 30C, and _______U, tells the computer to unlink from the current connection.

The RPT 1 callsign is the callsign of the repeater/hotspot/reflector that the transmission is being received by and forwarded to the internet from. In this photo the RPT 1 callsign, KC3ESS_B means that the transmission is going through the KC3ESS repeater and the B means a frequency in the UHF 70 centimeter band (420Mhz to 450Mhz). The callsign may also be REF063C which means the transmission is being received over the internet from reflector 63C.

The RPT 2 callsign is the destination callsign. In the photo above we have, KC3ESS_G, which means the destination of the transmission is the internet gateway on the KC3ESS repeater. Essentially that tells the computer connected to the KC3ESS repeater to send the transmission over the internet. If this were set to KC3ESS_B, the transmission would never leave the local KC3ESS repeater.

The target or URCALL field, RPT1 field, & RPT2 field all work together to route the DSTAR transmission to the appropriate location within the DSTAR network.

I also created a Gantt Chart for this project with a list of tasks.

Photos link to their respective sources.

Week 2

This week I continued my research on digital repeaters and software. I’ve decided to use a Raspberry Pi with the Pi-Star image, which contains software used to setup, configure, and maintain a digital repeater. It’s the most complete package I’ve seen and is widely recommended by other hams running digital repeaters. I have worked with this particular software package before so I have some understanding of how it works and how to use it. It basically contains many pieces of software which work together to manage and control a digital repeater. It can also be used to control digital multimode hotspots (duplex or simplex hotspots).

Pi-Star contains the popular digital radio software created by Jonathan Naylor, G4KLX: ircDDBGateway, DSTARRepeater, DMRGateway, and MMDVMHost. It also contains a complete dashboard and can support a wide variety of hardware. MMDVM stands for Multi Mode Digital Voice Modem.

The Raspberry Pi is a great piece of hardware for projects like this due to its cost, reliability, availability, and small size. I will be using the one I have already, a Pi 3B.

Capstone Project Proposal

For my capstone project, I want to build a digital multimode amateur radio repeater.

Amateur Radio is a two way radio service which in the United States is licensed by the Federal Communications Commission (FCC). It allows amateur radio operators the ability to talk to one another around the world using radio and to experiment with/design radio(s) and radio antennas. Amateur radio is often called “ham” radio. Ham radio is also used during natural disasters/emergencies to communicate when all other means of communication have failed.

I earned my Extra Class license about nine years ago. The Extra Class license is the highest license class that one can earn. While I’m not very active on the air talking to people, I enjoy the electronics and technology side of ham radio. More recently I have been working with digital repeaters, mainly Digital Smart Technology Amateur Radio (DSTAR) repeaters and occasionally Digital Mobile Radio (DMR) repeaters.

For my capstone I want to setup a multimode digital repeater that will switch between DSTAR and DMR depending on the signal it receives. This will be accomplished through the use of readily available software running on a Raspberry Pi that will be interfaced with a radio operating in the 70cm band.

The project will include a Nextion display to display information about the repeater and who is currently talking & allow one to control the repeater via touchscreen. I will design a screen layout for the Nextion display using Nextion Editor.

I will also add or enable a few extra features such as remote control through the ircDDBRemote app for DSTAR, remote SSH access, automatic linking based on a schedule, and possibly a few more as time permits.

I would like to learn how to design or modify and print a 3D printed case for my project too. 3D printing is something I have very limited experience with and would like to learn more about.