sp3rat / rtl-sdr-scanner-cpp

Introduction

This project contains sdr scanner written in c++ to scan and record multiple interesting frequencies bandwidth in the same time (eg. 108 MHz, 144 MHz, 440 Mhz, etc). This is possible by switching quickly between frequencies bandwidth.

Sdr scanner also allows you to record multiple transmissions simultaneously (if they are transmitted on the same band). For example, if one transmission is on 145.200 MHz and the other is on 145.600 MHz, the scanner will record and save both!

It also provides easy but very powerful web panel to explore recordings and spectrograms.

Supported devices

• rtl-sdr
• HackRF

Sample data collected

YouTube video

Spectrogram	Transmission

Quickstart

Install docker

If you do not have docker installed, follow the instructions available at https://docs.docker.com/desktop/ to install docker and docker compose.

Run

Download sample configuration and docker file, then run it. Customize config.json to your needs.

mkdir -p sdr
cd sdr
wget https://github.com/shajen/rtl-sdr-scanner-cpp/raw/master/config.json
wget https://github.com/shajen/rtl-sdr-scanner-cpp/raw/master/docker-compose.yml
docker compose up

Wait a moment to collect data and open panel.

To update docker images to latest version type:

docker compose pull

Panel

Open http://localhost:8000/sdr/spectrograms/ and wait for data to collect.

Admin panel available at http://127.0.0.1:8000/admin/. Username: admin, password: password.

Config

All of the following examples should be used in the config.json file.

rtl-sdr

single frequency range

To scan single frequency range:

{
  "scanner_frequencies_ranges": [
    {
      "device_serial": "auto",
      "ranges": [
        {
          "start": 144000000,
          "stop": 146000000,
          "step": 1000,
          "sample_rate": 2048000
        }
      ]
    }
  }
}

ppm and gain

To set ppm to 5 and gain to 49.6:

{
  "devices": {
    "rtl_sdr": {
      "ppm_error": 5,
      "tuner_gain": 49.6,
      "offset": 0
    }
  }
}

HackRF

single frequency range

To scan single frequency range:

{
  "scanner_frequencies_ranges": [
    {
      "device_serial": "auto",
      "ranges": [
        {
          "start": 430000000,
          "stop": 450000000,
          "step": 2500,
          "sample_rate": 20480000
        }
      ]
    }
  }
}

gain

To set lna to 16 and gain to 42:

{
  "devices": {
    "hack_rf": {
      "lna_gain": 16,
      "vga_gain": 42,
      "offset": 0
    }
  }
}

Use multipe devices

To use two dongles with serials 11111111 and 22222222:

{
  "scanner_frequencies_ranges": [
    {
      "device_serial": "11111111",
      "ranges": [
        {
          "start": 144000000,
          "stop": 146000000,
          "step": 1000,
          "sample_rate": 2048000
        }
      ]
    },
    {
      "device_serial": "22222222",
      "ranges": [
        {
          "start": 440000000,
          "stop": 442000000,
          "step": 1000,
          "sample_rate": 2048000
        }
      ]
    }
  ]
}

If you have multiple rtl-sdr dongles with the same serial you can change it with rtl_eeprom -s 12345678.

Scan multipe frequencies ranges

To scan 144 Mhz - 146 Mhz and 440 Mhz - 442 Mhz in the same time:

{
  "scanner_frequencies_ranges": [
    {
      "device_serial": "auto",
      "ranges": [
        {
          "start": 144000000,
          "stop": 146000000,
          "step": 1000,
          "sample_rate": 2048000
        },
        {
          "start": 440000000,
          "stop": 442000000,
          "step": 1000,
          "sample_rate": 2048000
        }
      ]
    }
  ]
}

Custom sample rate, step and frequency range

Please note that sample_rate must fit to step. You should meet the following equation sample_rate / step = 2 ^ n.

The smaller the step, the more accurate the spectrogram, but the larger the file size and the higher the CPU consumption.

The most popular values:

sample_rate	step
1024000	250
1024000	500
1024000	1000
2048000	250
2048000	500
2048000	1000
10240000	625
10240000	1250
10240000	2500
20480000	625
20480000	1250
20480000	2500

Please note that rtl-sdr do not support sample_rate greather than 2500000.

Please note that sample_rate must be greather than (stop frequency range - start frequency range).

Advanced usage

Build from sources

CMake

Build

sudo apt-get install build-essential cmake ccache libprocps-dev libfftw3-dev libspdlog-dev librtlsdr-dev libhackrf-dev libliquid-dev nlohmann-json3-dev libmosquitto-dev libgtest-dev libgmock-dev
git clone https://github.com/shajen/rtl-sdr-scanner-cpp sdr-scanner
cd sdr-scanner
cmake -B build -DCMAKE_BUILD_TYPE=Release .
cmake --build build -j$(nproc)

Run

./build/auto-sdr config.json

Docker

Build

git clone https://github.com/shajen/rtl-sdr-scanner-cpp sdr-scanner
cd sdr-scanner
docker build -t shajen/sdr-scanner -f Dockerfile .

Run

docker run --rm -it -v ${PWD}/config.json:/config.json --device /dev/bus/usb:/dev/bus/usb shajen/sdr-scanner

Distributed application system

It is possible to run every module (sdr-broker, sdr-scanner and sdr-monitor) on different machines and connect them. Please familiar with docker-compose.yml to do it.

Contributing

In general don't be afraid to send pull request. Use the "fork-and-pull" Git workflow.

1. Fork the repo
2. Clone the project to your own machine
3. Commit changes to your own branch
4. Push your work back up to your fork
5. Submit a Pull request so that we can review your changes

NOTE: Be sure to merge the latest from upstream before making a pull request!

Donations

If you enjoy this project and want to thanks, please use follow link:

License

• GPLv3 license