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The E-Z Pass Decoder Agent

ZEPASSD: E-Z Pass Capture Agent

ZEPASSD is a software defined radio (SDR) agent for capturing nearby E-Z Pass metadata.

Dependencies

There are a number of third-party dependencies for ZEPASSD.

  • boost.program-options
  • boost.crc
  • boost.circular-buffer
  • libfftw3
  • libuhd 3.9.5 or later

Building

Clone the repo, install the above dependencies, and simply run make.

Usage

Usage: ./zepassd {options} [output filename]
Options:
  -h [ --help ]                    Get some help (this screen)
  -d [ --device ] arg              USRP device ID to use
  -c [ --center ] arg (=915750000) Center frequency
  -T [ --tx-gain ] arg (=75)       Transmit gain
  -t [ --tx-port ] arg (=A:A)      Transmit port on USRP
  -A [ --tx-ant ] arg (=TX/RX)     Transmit antenna on specified USRP TX port
  -R [ --rx-gain ] arg (=75)       Receive gain
  -r [ --rx-port ] arg (=A:A)      Receive port on USRP
  -a [ --rx-ant ] arg (=RX2)       Receive antenna on the specified USRP RX 
                                   port
  -P [ --pulse-len ] arg (=20)     Length of activation pulse, in microseconds
  --gps-pps                        Use the GPS PPS source and synchronize local
                                   time
  -p [ --pulse-spacing ] arg (=25) Pulse interval, in milliseconds
  -m [ --max-age ] arg (=30)       Maximum stale pass age, in seconds

For example:

./zepassd --device "serial=F00FC7C8" --tx-port "A:A" --rx-port "A:A" --tx-gain 87 --rx-gain 85 -p 20 foobar 

will start ZEPASSD on the specified USRP, on the given TX/RX ports, with the specified gains, a 20ms interval between activations, and will write the outputs to a file named foobar.

Hardware Compatibility

ZEPASSD will work with most radios that support UHD (i.e. USRPs). It relies on the event triggering in hardware that the USRP supports. There are other radios (such as LimeSDR?) that could offer the same capabilities.

License, Copyright, Author

ZEPASSD is licensed under the GPLv3 or later.

ZEPASSD is Copyright (c) 2018 Phil Vachon You can reach him at [email protected]