gps fix detector: add timeout

4 files changed, 59 insertions, 22 deletions

diff --git a/doc/example.ini b/doc/example.ini
index ee9d567..1c76766 100644
--- a/doc/example.ini
+++ b/doc/example.ini
@@ -182,17 +182,24 @@ txgain=2.0
 channel=13C
 
 ; The reference clock to use.
-; possible values : internal, external, MIMO
+; possible values : internal, external, MIMO, gpsdo
 refclk_source=internal
 
 ; The reference one pulse-per second to use
-; possible values : none, external, MIMO
+; possible values : none, external, MIMO, gpsdo
 pps_source=none
 
 ; Behaviour when external clock reference lock lost
 ; possible values: ignore, crash
 behaviour_refclk_lock_lost=ignore
 
+; The maximum accepted holdover time for the gpsdo.
+; Valid only if the refclk and pps_source are set to gpsdo.
+; Units: seconds
+; Set to 0 to disable holdover check
+; default value: 0
+max_gps_holdover_time=30
+
 ; section defining ZeroMQ output properties
 [zmqoutput]
 
diff --git a/src/DabMod.cpp b/src/DabMod.cpp
index ec1a4cd..dacc84e 100644
--- a/src/DabMod.cpp
+++ b/src/DabMod.cpp
@@ -559,6 +559,8 @@ int launch_modulator(int argc, char* argv[])
                 throw std::runtime_error("Configuration error");
             }
 
+            outputuhd_conf.maxGPSHoldoverTime = pt.get("uhdoutput.max_gps_holdover_time", 0);
+
             useUHDOutput = 1;
         }
 #endif
@@ -671,10 +673,14 @@ int launch_modulator(int argc, char* argv[])
         fprintf(stderr, " UHD\n"
                         "  Device: %s\n"
                         "  Type: %s\n"
-                        "  master_clock_rate: %ld\n",
+                        "  master_clock_rate: %ld\n"
+                        "  refclk: %s\n"
+                        "  pps source: %s\n",
                 outputuhd_conf.device.c_str(),
                 outputuhd_conf.usrpType.c_str(),
-                outputuhd_conf.masterClockRate);
+                outputuhd_conf.masterClockRate,
+                outputuhd_conf.refclk_src.c_str(),
+                outputuhd_conf.pps_src.c_str());
     }
 #endif
     else if (useZeroMQOutput) {
diff --git a/src/OutputUHD.cpp b/src/OutputUHD.cpp
index 090602a..06efb82 100644
--- a/src/OutputUHD.cpp
+++ b/src/OutputUHD.cpp
@@ -225,13 +225,15 @@ OutputUHD::OutputUHD(
     }
     else if (myConf.refclk_src == "gpsdo") {
         uwd.check_refclk_loss = true;
-        uwd.check_gpsfix = true;
+        uwd.check_gpsfix = (myConf.maxGPSHoldoverTime != 0);
     }
     else {
         uwd.check_refclk_loss = true;
         uwd.check_gpsfix = false;
     }
 
+    uwd.max_gps_holdover = myConf.maxGPSHoldoverTime;
+
     SetDelayBuffer(config.dabMode);
 
     shared_ptr<barrier> b(new barrier(2));
@@ -410,14 +412,15 @@ void UHDWorker::process_errhandler()
     uwd->logger->level(warn) << "UHD worker terminated";
 }
 
-bool gps_fix_ok(struct UHDWorkerData *uwd)
+// Check function for GPS fixtype
+bool check_gps_fix_ok(struct UHDWorkerData *uwd)
 {
     try {
         std::string fixtype(
                 uwd->myUsrp->get_mboard_sensor("gps_fixtype", 0).to_pp_string());
 
         if (fixtype.find("3d fix") == std::string::npos) {
-            uwd->logger->level(alert) << "OutputUHD: GPS lost fix : " << fixtype;
+            uwd->logger->level(warn) << "OutputUHD: " << fixtype;
 
             return false;
         }
@@ -425,7 +428,7 @@ bool gps_fix_ok(struct UHDWorkerData *uwd)
         return true;
     }
     catch (uhd::lookup_error &e) {
-        uwd->logger->level(warn) << "no gps_fixtype sensor";
+        uwd->logger->level(warn) << "OutputUHD: no gps_fixtype sensor";
         return false;
     }
 }
@@ -438,8 +441,10 @@ void UHDWorker::process()
     double last_pps   = 2.0;
     double usrp_time;
 
+    // Variables needed for GPS fix check
     double last_gps_fix_check = 0.0;
-    const double gps_fix_check_interval = 5.0; // seconds
+    const double gps_fix_check_interval = 10.0; // seconds
+    int num_checks_without_gps_fix = 0;
     boost::packaged_task<bool> gps_fix_pt;
     boost::unique_future<bool> gps_fix_future;
     boost::thread gps_fix_task;
@@ -547,36 +552,49 @@ void UHDWorker::process()
         usrp_time = uwd->myUsrp->get_time_now().get_real_secs();
 
         if (uwd->check_gpsfix and
-                last_gps_fix_check + gps_fix_check_interval < usrp_time) {
+                // Divide interval by two because we alternate between
+                // launch and check
+                last_gps_fix_check + gps_fix_check_interval/2.0 < usrp_time) {
             last_gps_fix_check = usrp_time;
 
             // Alternate between launching thread and checking the
             // result.
             if (gps_fix_task.joinable()) {
                 if (gps_fix_future.has_value()) {
-                    uwd->logger->level(warn) << "GPSFIX " << usrp_time <<
-                        " Future ready";
 
                     gps_fix_future.wait();
 
                     gps_fix_task.join();
 
                     if (not gps_fix_future.get()) {
-                        throw std::runtime_error("Lost GPS Fix.");
+                        if (not num_checks_without_gps_fix) {
+                            uwd->logger->level(alert) <<
+                                "OutputUHD: GPS Fix lost";
+                        }
+                        num_checks_without_gps_fix++;
+                    }
+                    else {
+                        if (num_checks_without_gps_fix) {
+                            uwd->logger->level(info) <<
+                                "OutputUHD: GPS Fix recovered";
+                        }
+                        num_checks_without_gps_fix = 0;
                     }
-                }
-                else {
-                    uwd->logger->level(warn) << "GPSFIX " << usrp_time <<
-                        " Future not ready yet";
-                }
 
+                    if (gps_fix_check_interval * num_checks_without_gps_fix >
+                            uwd->max_gps_holdover) {
+                        std::stringstream ss;
+                        ss << "Lost GPS fix for " << gps_fix_check_interval *
+                            num_checks_without_gps_fix << " seconds";
+                        throw std::runtime_error(ss.str());
+                    }
+                }
             }
             else {
-                uwd->logger->level(warn) << "GPSFIX " << usrp_time <<
-                    " Launching task";
-
+                // Checking the sensor here takes too much
+                // time, it has to be done in a separate thread.
                 gps_fix_pt = boost::packaged_task<bool>(
-                        boost::bind(gps_fix_ok, uwd) );
+                        boost::bind(check_gps_fix_ok, uwd) );
 
                 gps_fix_future = gps_fix_pt.get_future();
 
diff --git a/src/OutputUHD.h b/src/OutputUHD.h
index 03acd94..2017f60 100644
--- a/src/OutputUHD.h
+++ b/src/OutputUHD.h
@@ -120,8 +120,13 @@ struct UHDWorkerData {
     // If we want to verify loss of refclk
     bool check_refclk_loss;
 
+    // If we want to check for the gps_fixtype sensor
     bool check_gpsfix;
 
+    // After how much time without fix we abort
+    int max_gps_holdover; // seconds
+
+
     // muting set by remote control
     bool muting;
 
@@ -183,6 +188,7 @@ struct OutputUHDConfig {
     bool enableSync;
     bool muteNoTimestamps;
     unsigned dabMode;
+    unsigned maxGPSHoldoverTime;
 
     /* allowed values : auto, int, sma, mimo */
     std::string refclk_src;