Installation

USB SDR Device
To use Salamandra you nee to have a SDR (Software Define Radio) device. It can be any from the cheap USB devices, such as this.

rtl_power software
Salamandra needs the rtl_power software installed in your computer. To install it you can do:

• On MacOS:
  sudo port install rtl-sdr
  

If you don't have ports in your MAC, see port installation

• On Linux:
  apt-get install rtl-sdr
  
• On Windows: See http://www.rtl-sdr.com/getting-the-rtl-sdr-to-work-on-windows-10/
  

If rtl_power was installed correctly, you should be able to run this command in any console:

rtl_test

And you should see one device detected.

Usage

Basic usage for detecting microphones

./salamandra.py 

This command will use a default threshold of 10.8, a min freq of 100Mhz, a max freq of 400Mhz and sound. You can change the default values with parameters.

Location Mode to find Hidden Microphones

• Run Salamandra with a threshold of 0, starting in the frequency 100MHz and ending in the frequency 200MHz. Search is activated with (-s). And make sounds (-S)
  ./salamandra.py -t 0 -a 100 -b 200 -s -S
  

Location Mode from a stored rtl_power file

./salamandra.py -t 0 -a 111 -b 113 -s -f stored.csv

To actually create the file with rtl_power, from 111MHz to 114MHz, with 4000Khz step, gain of 25, integration of 1s and capturing for 5min, you can do:

rtl_power -f 111M:114M:4000Khz -g 25 -i 1 -e 300 stored.csv

Detection Mode (deprecated now). To detect microphones in one pass.

• Run Salamandra with a threshold of 0, starting in the frequency 100MHz and ending in the frequency 200MHz. Search is activated with (-s). And make sounds (-S)
  ./salamandra.py -t 10.3 -a 100 -b 200 -F 2
  

Tips

• The wider the range of frequencies selected, the longer the analysis takes.
• The wider the range, the more probabilities to find microphones.
• Once you know the prob freq you can narrow it down with the parameters.

TODO

1. Make more clear if there is a detection or not
2. Separate the FP by
   • Sound generation based on the length of the histogram
   • Discard the frequencies that do not look like analog audio (Equidistant freqs)
3. Logs in file
4. Make the execution of rtl_power in another process in the background