next: generalized the GPS interface to any USRP device. just give it a function to write/read strings to UART.

not sure if i'm happy with the interface; maybe inheriting is cleaner. this works though.
gps interface for usrp2 is disabled right now in mboard_impl.

1 files changed, 210 insertions, 0 deletions

diff --git a/host/lib/usrp/gps_ctrl.cpp b/host/lib/usrp/gps_ctrl.cpp
new file mode 100644
index 000000000..3c7c00134
--- /dev/null
+++ b/host/lib/usrp/gps_ctrl.cpp
@@ -0,0 +1,210 @@
+//
+// Copyright 2010 Ettus Research LLC
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+#include <uhd/usrp/gps_ctrl.hpp>
+#include <uhd/utils/assert.hpp>
+#include <boost/cstdint.hpp>
+#include <string>
+#include <boost/date_time/posix_time/posix_time.hpp>
+#include <boost/thread.hpp>
+#include <boost/algorithm/string/trim.hpp>
+#include <boost/tokenizer.hpp>
+
+using namespace uhd;
+using namespace boost::gregorian;
+using namespace boost::posix_time;
+using namespace boost::algorithm;
+
+/*!
+ * A GPS control for Jackson Labs devices (and other NMEA compatible GPS's)
+ */
+
+//TODO: multiple baud rate support (requires mboard_impl changes for poking UART registers)
+class gps_ctrl_impl : public gps_ctrl{
+public:
+  gps_ctrl_impl(gps_send_fn_t send, gps_recv_fn_t recv){
+    _send = send;
+    _recv = recv;
+
+    std::string reply;
+    bool i_heard_some_nmea = false, i_heard_something_weird = false;
+
+    gps_type = GPS_TYPE_NONE;
+
+//    set_uart_baud_rate(GPS_UART, 115200);
+    //first we look for a Jackson Labs Firefly (since that's what we sell with the USRP2+...)
+
+    _recv(); //get whatever junk is in the rx buffer right now, and throw it away
+    _send("HAAAY GUYYYYS\n"); //to elicit a response from the Firefly
+
+    //then we loop until we either timeout, or until we get a response that indicates we're a JL device
+    int timeout = GPS_TIMEOUT_TRIES;
+    while(timeout--) {
+      reply = safe_gps_read();
+      if(trim_right_copy(reply) == "Command Error") {
+        gps_type = GPS_TYPE_JACKSON_LABS;
+        break;
+      }
+      else if(reply.substr(0, 3) == "$GP") i_heard_some_nmea = true; //but keep looking for that "Command Error" response
+      else if(reply.length() != 0) i_heard_something_weird = true; //probably wrong baud rate
+      boost::this_thread::sleep(boost::posix_time::milliseconds(200));
+    }
+
+    if((i_heard_some_nmea) && (gps_type != GPS_TYPE_JACKSON_LABS)) gps_type = GPS_TYPE_GENERIC_NMEA;
+
+    //otherwise, we can try some other common baud rates looking to see if a GPS is connected (todo, later)
+    if((gps_type == GPS_TYPE_NONE) && i_heard_something_weird) {
+      std::cout << "GPS invalid reply \"" << reply << "\", assuming none available" << std::endl;
+    }
+
+    bool found_gprmc = false;
+
+    switch(gps_type) {
+    case GPS_TYPE_JACKSON_LABS:
+      std::cout << "Found a Jackson Labs GPS" << std::endl;
+      //issue some setup stuff so it spits out the appropriate data
+      //none of these should issue replies so we don't bother looking for them
+      //we have to sleep between commands because the JL device, despite not acking, takes considerable time to process each command.
+       boost::this_thread::sleep(boost::posix_time::milliseconds(FIREFLY_STUPID_DELAY_MS));
+      _send("SYST:COMM:SER:ECHO OFF\n");
+       boost::this_thread::sleep(boost::posix_time::milliseconds(FIREFLY_STUPID_DELAY_MS));
+      _send("SYST:COMM:SER:PRO OFF\n");
+       boost::this_thread::sleep(boost::posix_time::milliseconds(FIREFLY_STUPID_DELAY_MS));
+      _send("GPS:GPGGA 0\n");
+       boost::this_thread::sleep(boost::posix_time::milliseconds(FIREFLY_STUPID_DELAY_MS));
+      _send("GPS:GGAST 0\n");
+       boost::this_thread::sleep(boost::posix_time::milliseconds(FIREFLY_STUPID_DELAY_MS));
+      _send("GPS:GPRMC 1\n");
+       boost::this_thread::sleep(boost::posix_time::milliseconds(FIREFLY_STUPID_DELAY_MS));
+
+//      break;
+
+    case GPS_TYPE_GENERIC_NMEA:
+      if(gps_type == GPS_TYPE_GENERIC_NMEA) std::cout << "Found a generic NMEA GPS device" << std::endl;
+      found_gprmc = false;
+      //here we loop around looking for a GPRMC packet. if we don't get one, we don't have a usable GPS.
+      timeout = GPS_TIMEOUT_TRIES;
+      while(timeout--) {
+        reply = safe_gps_read();
+        if(reply.substr(0, 6) == "$GPRMC") {
+          found_gprmc = true;
+          break;
+        }
+      }
+      if(!found_gprmc) {
+        if(gps_type == GPS_TYPE_JACKSON_LABS) std::cout << "Firefly GPS not locked or warming up." << std::endl;
+        else std::cout << "GPS does not output GPRMC packets. Cannot retrieve time." << std::endl;
+        gps_type = GPS_TYPE_NONE;
+      }
+      break;
+
+    case GPS_TYPE_NONE:
+    default:
+      break;
+
+    }
+
+
+  }
+
+  ~gps_ctrl_impl(void){
+
+  }
+
+//TODO: this isn't generalizeable to non-USRP2 USRPs.
+  std::string safe_gps_read() {
+    std::string reply;
+    try {
+        reply = _recv();
+    } catch (std::runtime_error err) {
+      if(err.what() != std::string("usrp2 no control response")) throw; //sorry can't cope with that
+      else { //we don't actually have a GPS installed
+        reply = std::string();
+      }
+    }
+    return reply;
+  }
+
+  ptime get_time(void) {
+    std::string reply;
+    ptime now;
+    boost::tokenizer<boost::escaped_list_separator<char> > tok(reply);
+    std::vector<std::string> toked;
+    int timeout = GPS_TIMEOUT_TRIES;
+    bool found_gprmc = false;
+    switch(gps_type) {
+    case GPS_TYPE_JACKSON_LABS: //deprecated in favor of a single NMEA parser
+    case GPS_TYPE_GENERIC_NMEA:
+
+      while(timeout--) {
+        reply = safe_gps_read();
+        if(reply.substr(0, 6) == "$GPRMC") {
+          found_gprmc = true;
+          break;
+        }
+      }
+      UHD_ASSERT_THROW(found_gprmc);
+
+      tok.assign(reply);
+      toked.assign(tok.begin(), tok.end());
+
+      UHD_ASSERT_THROW(toked.size() == 11); //if it's not we got something weird in there
+
+      now = ptime( date( 
+                         greg_year(boost::lexical_cast<int>(toked[8].substr(4, 2)) + 2000), //just trust me on this one
+                         greg_month(boost::lexical_cast<int>(toked[8].substr(2, 2))), 
+                         greg_day(boost::lexical_cast<int>(toked[8].substr(0, 2))) 
+                       ),
+                   hours(  boost::lexical_cast<int>(toked[1].substr(0, 2)))
+                 + minutes(boost::lexical_cast<int>(toked[1].substr(2, 2)))
+                 + seconds(boost::lexical_cast<int>(toked[1].substr(4, 2)))
+                 );
+      break;
+    case GPS_TYPE_NONE:
+    default:
+      throw std::runtime_error("get_time(): Unsupported GPS or no GPS detected\n");
+      break;
+    }
+    return now;
+  }
+
+  bool gps_detected(void) {
+    return (gps_type != GPS_TYPE_NONE);
+  }
+
+private:
+  gps_send_fn_t _send;
+  gps_recv_fn_t _recv;
+
+  enum {
+    GPS_TYPE_JACKSON_LABS,
+    GPS_TYPE_GENERIC_NMEA,
+    GPS_TYPE_NONE
+  } gps_type;
+
+  static const int GPS_TIMEOUT_TRIES = 5;
+  static const int GPS_TIMEOUT_DELAY_MS = 200;
+  static const int FIREFLY_STUPID_DELAY_MS = 200;
+
+};
+
+/***********************************************************************
+ * Public make function for the GPS control
+ **********************************************************************/
+gps_ctrl::sptr gps_ctrl::make(gps_send_fn_t send, gps_recv_fn_t recv){
+    return sptr(new gps_ctrl_impl(send, recv));
+}