ckuethe / gr-nmea

Adding NMEA and GPSD data to gnuradio flowgraphs

gr-nmea

This module includes a couple of blocks to connect to either a NMEA0183 GPS or a gpsd instance (for shared receivers or non NMEA protocols. This can be used to inject position, velocity, and time information into flowgraphs or recordings.

Usage

Instantiate an nmea_gpsd or nmea_serial block in your flowgraph. The raw NMEA output is available on the out port and can probably be safely discarded; asynchronous messages resulting from the parsing of the NMEA stream is available on the gps_msg port.

Both nmea_gpsd.py and nmea_serial.py can be run as standalone programs to demonstrate their functionality.

Dependencies

pynmea2 is required for NMEA0183 parsing

gpsd is useful for multiplexed device access, though not required for these modules

gr-nmea's Issues

Dictionary read wrong in cpp

Reading the PMT in c++ gives the wrong key value pairs, like so

******* MESSAGE DEBUG PRINT ********

Dictionary Keys: ((gps_time . 2017-05-15 12:23:41))

Dictionary Values: (((longitude . 23.8505) (latitude . 38.0829) (valid . #t) (host_time . 2017-05-15 12:23:41.843005) (protocol . nmea) (id . RMC)))
(((gps_time . 2017-05-15 12:23:41) (longitude . 23.8505) (latitude . 38.0829) (valid . #t) (host_time . 2017-05-15 12:23:41.843005) (protocol . nmea) (id . RMC)))

---

This output results from reading the keys, then values, then printing, like so

void reader_impl::print(pmt::pmt_t msg)
{
std::cout << "******* MESSAGE DEBUG PRINT ********\n";

  std::cout<<"\nDictionary Keys: "<<pmt::dict_keys(msg)<<"\n";
std::cout<<"\nDictionary Values: "<<pmt::dict_values(msg)<<"\n";
//auto m = mappify1(pmt::symbol_to_string(msg));
//for(auto const& p: m)
//    std::cout << '{' << p.first << " => " << p.second << '}' << '\n';
  pmt::print(msg);
  std::cout << "************************************\n";
}

Am I doing something wrong? Or are pmts read differently in python and cpp?

GNU Radio 3.8

Hi there!
Is it possible to make gr-nmea work in GNU Radio 3.8?
Thanks a lot!