Amateur Radio adventures with Satellites

Longmynd Client

This is a windows client for Longmynd, an opensource ATV client. I wanted to keep my minitiouner in the shack, but use the client elsewhere. This connects to a modified version of longmynd and it allows you to control and show the stream if its locked onto a transmission.


  • * Connect to longmynd from multiple clients across your network.
  • * If running in multicast mode then all clients can show the stream, in unicast mode longmynd will send the TS stream to the client it last received a frequency command from
  • * Live Oscar 100 spectrum (from here), can be disabled if using for terrestrial or when offline
  • * Control Tuner port selection and voltage
  • * Callsigns visible on spectrum as it locks to a signal
  • * Auto or manual snapshots

Raspberry PI Setup

Note: This requires a modified version of Longmynd done by Phil Crump (M0DNY)

  1. Flash your raspberry pi sd card with the Raspberry PI OS (Legacy) – Buster – released 2022-04-04
  2. Boot raspberry pi, connect to network and enable ssh using raspi-config
    sudo raspi-config
  3. Install dependencies
    sudo apt-get install cmake git make gcc libusb-1.0-0-dev libasound2-dev
  4. Clone repository
    git clone https://github.com/philcrump/longmynd.git
  5. Compile modified longmynd
    cd longmynd && make
  6. Install udev rules
    sudo cp minitiouner.rules /etc/udev/rules.d/


If you have been using a previous version of longmynd + client then you might need to update your longmynd on the raspberry pi:

  1. Stop longmynd
  2. cd /home/pi/longmynd
  3. git pull
  4. make
  5. Start longmynd


Run longmynd specifying the following parameters (adapt to your network)

./longmynd -W 8080 -i 4003 -I 4002 741538 1500


8080 is the configured web/websocket port. is my windows pc running the client
4003 is the UDP TS Port
4002 is the UDP Status Port
714538 is the initial frequency
1500 is the initial symbol rate

Launch the client on your windows pc and configure the following settings:

Longmynd Settings

Host: IP of the machine where longmynd is running
TS UDP Port: The UDP port specified to longmynd for the TS
WS Port: The Websocket port specified to longmynd
Freq Offset Port 0: Frequency offset for Port 0
Freq Offset Port 1: Frequency offset for Port 1
Default Tuner Port: Which port should be selected by default
Enable LNB Power: Enables power output when application is started
Enable Horiz Pol: Enable horizontal polarization (higher voltage for LNB, normally around 18v)
Modes: The modes define how the client will control the output TS stream from longmynd. Either stick to longmynd parameters, or automatically update the TS stream ip on client settings. (Usefull for running the client on multiple pc’s and have the TS stream go to a specific ip depending on which client sent a frequency change command.

Snapshot Settings

Snapshot Folder: Where the snapshot files will be saved
Snapshot Time: When using auto snapshot, this determines the time the client will wait before doing a snapshot once it has locked on to a signal.

Autotune Settings

Wait Time: If you run autotune (timed) then this specifies how long it will stay on a transmission before it selects the next transmission.
Avoid Beacon: Don’t switch to the beacon when auto tuning.

VLC Settings

VLC Hardware Decoding: Whether VLC library should use hardware decoding or not. I have had some freezing issue on the video of some transmissions. Disabling the hardware decoding fixed this. Your mileage may vary.

Oscar 100 Spectrum

Enable: If using the client for other than Oscar 100 DATV then you can disable the spectrum (it won’t connect to the internet then to get spectrum data)


The client needs a restart after saving your settings. You can select the signal on the spectrum below or specify a frequency and symbol rate manually.


If you use and enjoy my software and would like to support future projects, then you can buy me a beer.

Download – 2022/05/18


2022/05/18 – TS Control, Tuner Port Control, Improved spectrum including callsigns, LNB Power control, Fixed misc small bugs

2022/05/11 – Fixed snapshot png bug, added autotune, volume control, snapshot path setting

2022/05/08 – Fixed bug where the offset value wasn’t being saved properly

2022/05/07 – Initial Test Version


  1. If you are using the correct version of longmynd then you should be able to connect to the experimental web interface of longmynd (http://<your pi ip>:8080)
  2. If the client is communicating with longmynd, but there is no video. Use vlc on windows side to test that your longmynd and networksettings are setup correctly. You can connect to TS UDP stream using udp://@:4003 from vlc.

Credits & Thanks

Thanks to the following individuals who have spent a lot time to help test it:
Martin – G4FKK
Benno – PA3FBX
Henry – ZS6MC

Credit to Phil Crump (M0DNY) for his modified longmynd and to Rob Swinbank (M0DTS) for sharing his quicktune code for the wideband spectrum display.