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Raspberry Pi / Debian

Smaller radio systems can be covered using a Raspberry Pi. If you are interested in doing this, you should really get a Pi 4. It maybe possible to get things running on an older Pi, but you often get unexpect behavior and errors. A Pi 4 can handle 3-4 simulatanious recordings. Make sure you have a good power supply. Also pay attention to heat. If the Pi gets too hot, it will slow down. A good case or fan can help keep it going full tilt. You can also just run debian on a NUC or Miniform PC. These commands will work with a vaneilla debian install as well.

RaspberryOS (aka Raspbian)​

Setup Raspbian​

This is a good guide on how to setup a Raspberry Pi in headless mode. This means that you do not have to attach a monitor, keyboard or mouse to it to get it working. The steps below are pulled from this guide.

Download and burn the image​

The first step is to put the Raspberry Pi OS onto a MicroSD card. You will need to have a USB MicroSD card adaptor, so you can connect it to your computer. Either of these approaches should work:

Setup for headless boot​

After the OS has been written to MicroSD card, we need to change a few files so that the Pi can get on Wifi and also allow for SSH connections. See the guide for how to do it using Windows.

  • On a Mac touch /Volumes/boot/ssh
  • Next, add the WiFi info
    • nano /Volumes/boot/wpa_supplicant.conf
country=US
ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1

network={
    ssid="NETWORK-NAME"
    psk="NETWORK-PASSWORD"
}
  • Eject the MicroSD card (first in the OS and then physhically from the reader)
  • Put the MicroSD card in the Pi and power it on.

Remote Access​

This is a good guide for how to find and connect to a Pi on your network.

These steps should work on a Mac and assume you only have one Pi on the Network

  • Check to see if it is up: ping raspberrypi.local
  • Clear old known hosts: ssh-keygen -R raspberrypi.local
  • See if you can connect: ssh pi@raspberrypi.local default password is: raspberry
  • Exit: exit
  • Create your SSH keys if you don't have them yet: ssh-keygen
  • Send over you keys: ssh-copy-id pi@raspberrypi.local

Setup​

The following steps setup all of the libraries needed to build Trunk Recorder.

  • Add the Debian Multimedia source and include non-free libraries, like fdkaac. Edit the sources.list file: 
sudo nano /etc/apt/sources.list
  • and add this line to the end:
deb https://www.deb-multimedia.org bookworm main non-free
  • Download the keys for the apt source and install them:
wget https://www.deb-multimedia.org/pool/main/d/deb-multimedia-keyring/deb-multimedia-keyring_2016.8.1_all.deb
sudo dpkg -i deb-multimedia-keyring_2016.8.1_all.deb
  • You can verify the package integrity with:
sha256sum deb-multimedia-keyring_2016.8.1_all.deb
9faa6f6cba80aeb69c9bac139b74a3d61596d4486e2458c2c65efe9e21ff3c7d deb-multimedia-keyring_2016.8.1_all.deb
  • Update the OS:
sudo apt update
sudo apt upgrade
  • Add all of the libraries needed:
sudo apt -y install libssl-dev openssl curl git fdkaac sox libcurl3-gnutls libcurl4 libcurl4-openssl-dev gnuradio gnuradio-dev gr-osmosdr libhackrf-dev libuhd-dev cmake make build-essential libboost-all-dev libusb-1.0-0-dev libsndfile1-dev

Configure RTL-SDRs to load correctly:

sudo wget https://raw.githubusercontent.com/osmocom/rtl-sdr/master/rtl-sdr.rules ~/rtl-sdr.rules
sudo mv ~/rtl-sdr.rules /etc/udev/rules.d/20.rtlsdr.rules

You will need to restart for the rules to take effect. Logging out and logging back in will not be enough.

sudo shutdown -r now

Now go Build Trunk Recorder!

Ubuntu 22.04 Server (64-bit support!)

Ubuntu has a very good guide on setting up Ubuntu Server to run on a Raspberry Pi. Follow this to get started.

sudo apt update
sudo apt upgrade
sudo apt install -y apt-transport-https build-essential ca-certificates fdkaac git gnupg gnuradio gnuradio-dev gr-osmosdr libboost-all-dev libcurl4-openssl-dev libgmp-dev libhackrf-dev liborc-0.4-dev libpthread-stubs0-dev libssl-dev libuhd-dev libusb-dev pkg-config software-properties-common cmake sox libsndfile1-dev

If you are using a HackRF:

sudo apt install -y hackrf libhackrf-dev libhackrf0

Configure RTL-SDRs to load correctly:

sudo wget https://raw.githubusercontent.com/osmocom/rtl-sdr/master/rtl-sdr.rules  /etc/udev/rules.d/20.rtlsdr.rules

Building Trunk Recorder

In order to keep your copy of the Trunk Recorder source code free of build artifacts created by the build process, it is suggested to create a separate "out-of-tree" build directory. We will use trunk-build as our build directory.

Assuming you are in the desired directory to place both trunk-recorder and trunk-build folders to, perform the following...

cd ~
mkdir trunk-build
git clone https://github.com/robotastic/trunk-recorder.git
cd trunk-build
cmake ../trunk-recorder
make -j `nproc`
sudo make install

Note: If the Pi hangs during the make -j 'nproc' command, try make instead (it may take longer but may also prevent locking up the Pi due to all processor cores being 100% in use)

Profile​

(It takes about 15 minutes for this section.)

Run the command volk_profile to ensure that VOLK (Vector-Optimized Library of Kernels) uses the best SIMD (Single instruction, multiple data) architecture for your processor.

Configuring Trunk Recorder​

The next step is to configure Trunk Recorder for the system you are trying to capture.

Running trunk recorder.​

If all goes well you should now have the executable named trunk-recorder, and created the config.json configuration file as described in the Wiki and README.

From your build directory (e.g. trunk-build) you can now run ./trunk-recorder

Runtime options​

Trunk Recorder will look for a config.json file in the same directory as it is being run in. You can point it to a different config file by using the --config argument on the command line, for example: ./trunk-recorder --config=examples/config-wmata-rtl.json.