In November 2023 I described how to install DroidStar on you mobile phone (cellphone) to work digital radio modes. Click HERE to read Part 1.
In Part 2 (this article) I will be looking at installing DroidStar on a PC running Linux Mint 22 (Wilna).
What is DroidStar?
DroidStar is an open-source digital voice client application for Android, iOS, Windows, and Linux that allows amateur radio operators to connect to various digital voice modes—including DMR, D-Star, Fusion (YSF/FCS), M17, P25, NXDN, and AllStarLink (IAX2)—directly from their device without needing a radio or hot spot. It connects to reflectors via IP and supports software vocoders.
Key Features of DroidStar:
- No Radio Required: Enables access to digital networks directly from a smartphone or computer.
- Multi-Mode Support: Supports DMR, D-Star, C4FM (Fusion), M17, P25, and NXDN.
- AllStarLink: Functions as an IAX2 client to connect to AllStar nodes.
- Hardware Support: Compatible with AMBE USB devices (e.g., DVSI, DVstick 30) and MMDVM modems.
- Platforms: Available on the Google Play Store, iOS/Android, and via source code for desktop.
How it Works:
You do not need a hotspot for DroidStar to work, however you will have to sign-up for a DMR ID if you do not have one yet. You will also have to register with BrandMeister whose servers will enable you to link to different digital radio modes.
Register HERE to obtain a DMR ID
Register HERE to gain access to BrandMeister
DroidStar Vocoder Plugins Downloads (Needed for audio and TX to work)
Setting up a BrandMeister Password (Read more)
The above registrations need to be done before installing DroidStar. Google is your friend here to assist you in getting registered.
DroidStar connects to M17, Fusion (YSF/FCS, DN and VW modes are supported), DMR, P25, NXDN, D-STAR (REF/XRF/DCS) reflectors and AllStar nodes (as an IAX2 client) over UDP. It is compatible with all of the AMBE USB devices out there (ThumbDV, DVstick 30, DVSI, etc). It also supports MMDVM modems and can be used as a hotspot, or as a stand-alone transceiver via direct mode to the MMDVM device. This software is open source and uses the cross platform C++ library called Qt. It will build and run on Linux, Windows, MacOS, Android, and iOS.
Installing DroidStar on Linux Mint 22 (Wilna):
To install DroidStar on Linux Mint, the recommended method is using Flatpak via Flathub, as it manages dependencies easily. Alternatively, you can compile from source or use a pre-compiled binary if familiar with make. It requires a valid amateur radio callsign and DMR ID to operate.
Preferred Method : Installing via Flatpak (Recommended)
Open a terminal and run:
sudo flatpak install flathub io.github.nostar.DroidStar
You must ensure that the Vocoder Plugin is installed. For my system I installed the following Vocoder:
How to install the Vocoder?
Open DroidStar by launching the application from the Menu - Sound and Video - DroidStar. Once open go to Settings and scroll down to the Vocoder URL slot. Copy the above pizzanbeer url link into the slot and click the Download vocoder button. The vocoder will be downloaded.
Setup DroidStar for use:
With DroidStar still open go to the Main heading. Select DMR, S2, CCo, BM_6551_South_Africa and TGID: 65522. Now go to Settings. Add your callsign, DMRID, ESSID = 01, BrandMeister Password and Location. Scroll down to Update hosts and Update ID files by clicking on the TABS. The log will show you the updates. Leave other settings as is. (default)
We are nearly ready to use DroidStar. If your Vocoder or Soundcard settings is not setup correctly Droidstar will crash (program close on desktop)
Lets look at the audio setup of DroidStar:
Linux Mint 22 uses AlsaMixer for audio purposes. I use alsamixer for Qtel Echolink Client and it works fine. However I found that DroidStar on my machine "preferred" PulseAudio. I am sure that you can use Alsa instead but DroidStar keep on crashing if I tried to use it on my machine.
Therefor I had to stop Alsa from directly controlling the audio hardware and force DroidStar to use PulseAudio.
To
stop ALSA and use PulseAudio in DroidStar on a Linux system, you need
to ensure PulseAudio is running and properly configured to handle the
audio routing, allowing it to act as the intermediate server between
DroidStar and the underlying ALSA drivers.
Here are the steps to switch from ALSA to PulseAudio:
1. Ensure PulseAudio is Running
If PulseAudio was disabled or replaced by ALSA, restart it:
Open a Terminal window and enter
sudo pulseaudio --start
2. Configure DroidStar for PulseAudio
- Open DroidStar.
- Go to the settings or audio configuration menu.
- Locate the input and output device settings.
- Select PulseAudio (or
default) rather than selecting direct ALSA hardware devices (likehw:0,0).
3. Ensure PulseAudio Takes Control of ALSA
If
ALSA is grabbing the hardware exclusively, PulseAudio cannot function.
To force PulseAudio to take control, you may need to prevent ALSA from
autospawning, or kill existing ALSA processes if they are blocking it.
- Check/Kill PulseAudio:
pulseaudio -k - Restart PulseAudio:
pulseaudio --start - Ensure it's loaded:
pactl info
Forcing
DroidStar to use PulseAudio generally applies to running the
application on Linux-based systems (like Raspberry Pi or desktop Linux)
rather than Android, where DroidStar typically uses the native Android
Audio HAL
. On Linux, DroidStar is a Qt application and will default to PulseAudio
if it is active on the system. If it is not defaulting to it, you can
force it using environment variables.
Using
SDL_AUDIODRIVER=pulseaudio
before launching DroidStar on Linux is a common workaround to force the
application to use the PulseAudio sound server, which can resolve
issues where the app fails to initialize audio or has no sound output. Run DroidStar from your terminal with the following command:
We are using the Flatpak version of DroidStar, you may need to use:
flatpak run --env=SDL_AUDIODRIVER=pulseaudio io.github.nostar.DroidStar
Why this is necessary:
- SDL2 Backend Selection: Modern SDL2 applications often need to explicitly be told to use
pulseaudiorather thanpulse(which is for older SDL1.2) to work correctly, particularly on newer Linux distributions. - Fixing Audio Issues: If DroidStar shows it is receiving packets (RX) but you have no sound, or if it crashes on startup, it is likely unable to properly connect to your system's audio output.
- Vocoder Requirements: For modes like D-Star, DMR, and Fusion, DroidStar requires a vocoder plugin to function, which should be downloaded and configured in the settings tab.
Troubleshooting Audio Issues:
If DroidStar is connected but has no audio output, it might be using the wrong sound card.
- Use
pavucontrol: Install and openpavucontrol(PulseAudio Volume Control) while DroidStar is running and connected. You can select the specific input/output device under the "Recording" or "Playback" tabs for the DroidStar app. - Check Build Dependencies: Ensure your Linux system has the proper PulseAudio development libraries installed before compiling:
sudo apt install libpulse-dev- ALSA still grabbing device: If PulseAudio isn't taking over, ensure that you do not have autospawn = no set in your /etc/pulse/client.conf.
cd /etc/pulse (enter)
sudo nano client.conf (enter)
Move curser to autospawn =yes and ensure that it is set to yes.
Reboot your computer and start DroidStar. You should be in business using DroidStar on DMR.
I currently use DroidStar to monitor my personal DMR Repeater TalkGroup 65522 which is permanently connected to AllStar and Echolink via the ZS1I DMR Bridge. More information available HERE.
Finally:
DroidStar is a fun, free and easy way to experiment with the digital radio modes. If you have an Android, IOS or PC and have an interest in playing around with digital radio modes, then get going with DroidStar.
That's it! You can now use DroidStar on Linux Mint 22 (Wilna) to access DMR and the ZS Link Netwerk.
Enjoy!!
Images: Click on images for larger view.
