YouTube videos.

• OSB2013 - Michael Ossmann - HackRF: Software Defined Radio for Software People.
  • Talk about Jawbreaker, the hardware that became HackRF One.
  • Demos of using GNU Radio Companion (GRC).
  • GRC data flow programming uses sources, sinks, and data processing blocks wired together.
    • Data flow blue is complex.
    • Complex numbers is key to understanding radio waves.
    • Data flow orange is float.
  • GRC Osmocom Source block supports HackRF One and other SDRs.
    • Need to set sample rate, RF gain, frequency.
  • Instrument WX FFT block to visualize signals.
    • 2.45 GHz is the center of the FFT plot.
    • FFT bandwidth is the sample rate.
    • The center spike is the DC offset, a limitation of the SDR implementation or artifact of the SDR implementation.
    • You ignore the DC offset spike and avoid the DC offset.
    • Peak hold shows WiFi burst.
    • Trick, use peak hold and move transmitter supper close to the HackRF One antenna.
    • FFT does not display all the data.
    • Use a file sink to capture all the data.
  • Set WX Slider to frequency
  • GRC creates a Python program.
  • Need to learn DSP and radio stuff.
  • Getting from the radio wave to the digital bits is the hard part.
  • FFT shows where signal exists.
  • Shift the frequency by multiply by complex exponential
  • -1e6 shifts the frequency down 1 MHz.
  • Filter data before demodulation.
  • HackRF One uses 8 bits I and 8 bits Q per seconds. Summary 16 Mbytes per second over the USB interface.
  • GRC converts the I/Q to a float number, results in 4X data rate, summary 64 Mbytes per seconds.
  • Need to look into Bod line??
  • Throttle to limit the simulation.