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Wenet RX Instructions (Linux using Docker)
Last Updated: 2024-11-16
The current simplest way of setting up a Wenet receiver station is to use the Docker image. This avoids the need to build dependencies, and lets you get into receiving quickly. Wenet Docker images are available for the majority of Linux platforms. Unfortunately we cannot provide docker images for Windows or OSX at this time
A huge thanks to Steven Honson for setting up the Docker containers and making this all possible!
Please contact me at vk5qi (at) rfhead.net if you have any issues with these instructions.
Wenet requires a RTLSDR to receive the transmitted signal, and of course some sort of antenna suited to the operating band (usually the 70cm amateur radio band). We highly recommend the 'v3' rtl-sdr.com dongles. (The v4 dongles may work, but have not been tested!)
Other SDRs with open-source APIs may be supported in the future...
Wenet transmissions are usually found on the upper half of the amateur 70cm band, with the nominal frequency used in South Australia being 443.5 MHz, and 441.2 MHz in Victoria. Depending on your distance from the Wenet transmitter, you will need some antenna gain for reliable reception. For best reception, a 5-element yagi works well. These are available commercially from places like Arrow Antennas, or you could build one yourself out of tape measure and PVC pipe.
To achieve best receive performance, a preamplifier should be used between the RTLSDR and the antenna, ideally as close to the antenna feed-point as possible. Examples of suitable amplifiers include:
- MiniKits options: Pre-built PGA-103-based Preamp; Kit Preamp
- UpuTronics Filtered Preamps: https://store.uputronics.com/index.php?route=product/category&path=59
- Cheapie options on AliExpress: Various options of varying quality. Search terms like 'SPF5189' will target results.
The Wenet receiver software can be configured to enable the Bias-Tee on the RTLSDR to power some preamplifiers via the coax. (Note that the MiniKits preamps required 12v and cannot be powered this way).
Wenet reception has been successful using the following platforms:
- Raspberry Pi 3B+
- Raspberry Pi 4
- Various Intel i3 Laptop computers running Ubuntu Linux (18.04 or newer)
Any reasonably modern single-board computer (Pi 3B+ performance or better) should be able to handle Wenet reception, and most modern laptops (when running a Linux OS) should also work.
As the Wenet receiver interface is now browser-based, your Linux installation will also need a modern-ish web browser, such as Firefox or Chromium.
If using a Raspberry Pi (3B+ or 4 recommended), I highly recommend installing Raspberry Pi OS using the Raspberry Pi Imager. This lets you pre-configure the OS with various settings. Some settings I recommend you change include:
- Enable SSH and set a username and password.
- Configure your WiFi details (note that if you are going to operate portable, you might need to set this to a mobile hotspot network!)
If running a Pi 3B+ or newer, use the "Raspberry Pi OS (64-bit)" or "Raspberry Pi OS Lite (64-bit)" (if only accessing the RPi via a network) versions. The latest Wenet images (as of 2024-07-21) have been confirmed to work on the latest Raspberry Pi OS version (Bookworm).
Once you've logged into the Pi for the first time (either via screen/keyboard/mouse or via SSH), ensure all your system packages are up to date by opening a terminal and running:
sudo apt-get update
sudo apt-get upgradeIt is highly recommended that you use the latest version of Docker, rather than the one available from your systems default package repositories. If you already have Docker installed, then hopefully you already know what you're doing here!
A quick way to install the latest version of Docker is by using the convenience script:
curl -fsSL https://get.docker.com -o get-docker.sh
sudo sh get-docker.shIf you see errors along the lines of "InRelease' changed its 'Suite' value from 'stable' to 'oldstable'", then you are likely running an out-of-date version of Raspbian. You can temporarily get around this error by running the command:
sudo apt update --allow-releaseinfo-changeTo be able to run docker commands as your non-root user (recommended), run:
sudo usermod -aG docker $(whoami)You will need to logout and log back in afterwards to pick up the changes to group membership (you can check this by running groups).
After logging out and back in, test that docker is available by running:
docker versionThis should return something along the lines of:
Client: Docker Engine - Community
Version: 20.10.14
API version: 1.41
... more lines here ...
Server: Docker Engine - Community
Engine:
Version: 20.10.14
API version: 1.41 (minimum version 1.12)
... more lines here ...
If you don't see the server section then you likely haven't give your user the correct permissions (see above).
The RTL DVB kernel modules must first be blacklisted on the Docker host. RTL-SDR itself is not required on the Docker host. This can be accomplished using the following commands:
echo 'blacklist dvb_usb_rtl28xxu' | sudo tee /etc/modprobe.d/blacklist-dvb_usb_rtl28xxu.conf
sudo modprobe -r dvb_usb_rtl28xxuIf the modprobe -r command errors, a reboot may be required to unload the module.
At this point it's recommended to disconnect and re-connect your RTLSDR, if it's already plugged in.
We will make a directory to store a startup script, and to save received images to:
mkdir -p ~/wenet/rx_images
cd ~/wenet/
curl -o start_docker.sh https://raw.githubusercontent.com/projecthorus/wenet/master/start_docker.sh
chmod +x start_docker.shNote: To run the latest testing version, replace start_docker.sh with start_docker_testing.sh in the commands above, and in any other instances below.
Modify the start_docker.sh script and update the fields within as appropriate. At the very least ensure you update your callsign!
You may also need to adjust the receive frequency depending on the launch you are receiving.
With your RTLSDR plugged in, from within the wenet directory, run the image by running:
$ ./start_docker.sh The first time this is run, it will download the required docker images, this may take a few minutes.
By default the Wenet docker image will start automatically on boot. See further below for information on how to disable this.
You can check the status of the container by checking the logs:
docker logs --tail 50 --follow wenetThis will usually show a lot of debug information, which may be a bit hard to interpret!
Open a web browser and navigate to: http://localhost:5003/
If all is working, this should show the Wenet web interface. The SNR value in the top-right corner should update even if only noise is being received (values of 3-4 dB are normal when receiving nothing). SNR values of >10dB are required for reliable reception of packets. Abnormally high values (e.g. >25 dB) may indicate you have a strong local interferer which the receiver is latching onto.
The main image display in the centre of the page will update as image packets are received. At the bottom of the page is further information on the image being received, and the status of packet uploads to ssdv.habhub.org. Also visible at the bottom of the page is the 'debug log' from the payload, showing the status of image capture and processing.
To see live image data received by all the receivers of a flight, visit https://ssdv.habhub.org/
Images received by just your station are available in the wenet/rx_images directory.
The container can be stopped by running:
$ docker stop wenetTo restart the container (for example, if you changed a setting in start_docker.sh, just re-run ./start_docker.sh.
Updating the docker image can be accomplished by running:
$ docker pull ghcr.io/projecthorus/wenet:latest
(If running the testing version, replace 'latest' with 'testing' in the above command)
You must then start the container again using the start_docker.sh script.
By default, the Wenet docker image will start automatically on boot.
If you do not want this to occur, you will need to modify the start_docker.sh scripts and remove the lines containing --restart="always" \
After you re-run start_docker.sh again, this will result in the wenet decoder not starting on system boot.