uhd: added call to readback time registers, work on locking clocks in mimo config

8 files changed, 65 insertions, 4 deletions

diff --git a/gr-uhd/lib/uhd_mimo_sink.cc b/gr-uhd/lib/uhd_mimo_sink.cc
index 9226d6004..6d603d7bc 100644
--- a/gr-uhd/lib/uhd_mimo_sink.cc
+++ b/gr-uhd/lib/uhd_mimo_sink.cc
@@ -92,6 +92,10 @@ public:
         return _dev->get_tx_antennas(chan);
     }
 
+    uhd::time_spec_t get_time_now(void){
+        return _dev->get_time_now();
+    }
+
     void set_time_next_pps(const uhd::time_spec_t &time_spec){
         return _dev->set_time_next_pps(time_spec);
     }
diff --git a/gr-uhd/lib/uhd_mimo_sink.h b/gr-uhd/lib/uhd_mimo_sink.h
index 280f7c0e8..951980908 100644
--- a/gr-uhd/lib/uhd_mimo_sink.h
+++ b/gr-uhd/lib/uhd_mimo_sink.h
@@ -114,6 +114,12 @@ public:
     virtual std::vector<std::string> get_antennas(size_t chan) = 0;
 
     /*!
+     * Get the current time registers.
+     * \return the current usrp time
+     */
+    virtual uhd::time_spec_t get_time_now(void) = 0;
+
+    /*!
      * Set the time registers at the next pps (across all mboards).
      * \param time_spec the new time
      */
diff --git a/gr-uhd/lib/uhd_mimo_source.cc b/gr-uhd/lib/uhd_mimo_source.cc
index bcd6aa695..fb811572b 100644
--- a/gr-uhd/lib/uhd_mimo_source.cc
+++ b/gr-uhd/lib/uhd_mimo_source.cc
@@ -46,10 +46,11 @@ public:
     {
         _dev = uhd::usrp::mimo_usrp::make(args);
         set_streaming(false);
+        sync_times(); //TODO may want option to disable this
     }
 
     ~uhd_mimo_source_impl(void){
-        //NOP
+        set_streaming(false);
     }
 
     void set_samp_rate_all(double rate){
@@ -93,6 +94,10 @@ public:
         return _dev->get_rx_antennas(chan);
     }
 
+    uhd::time_spec_t get_time_now(void){
+        return _dev->get_time_now();
+    }
+
     void set_time_next_pps(const uhd::time_spec_t &time_spec){
         return _dev->set_time_next_pps(time_spec);
     }
@@ -126,13 +131,33 @@ protected:
     const uhd::io_type_t _type;
     bool _is_streaming;
 
+    void sync_times(void){
+        //set the times to zero at the next pps and sleep (race condition)
+        set_time_next_pps(uhd::time_spec_t(0, 0)); sleep(1);
+
+        //catch the seconds rollover at the next pps
+        double last_frac_secs = 0.0, curr_frac_secs = 0.0;
+        while(curr_frac_secs > last_frac_secs){
+            last_frac_secs = curr_frac_secs;
+            curr_frac_secs = get_time_now().get_frac_secs();
+        }
+
+        //set the times to zero at the next pps and sleep (all boards synced)
+        set_time_next_pps(uhd::time_spec_t(0, 0)); sleep(1);
+    }
+
     void set_streaming(bool enb){
-        if (enb){ //FIXME TODO handle this better
+        if (enb){
+            //make an estimate of the trip time
+            uhd::time_spec_t time1 = get_time_now();
+            uhd::time_spec_t time2 = get_time_now();
+            double rtt = 2*(time2 - time1).get_real_secs();
+
+            //setup a stream command that starts streaming slightly in the future
             uhd::stream_cmd_t stream_cmd(uhd::stream_cmd_t::STREAM_MODE_START_CONTINUOUS);
             stream_cmd.stream_now = false;
-            stream_cmd.time_spec = uhd::time_spec_t(1, 0);
+            stream_cmd.time_spec = time2 + uhd::time_spec_t(0, (_dev->get_num_channels()+1)*rtt);
             _dev->issue_stream_cmd(stream_cmd);
-            sleep(1);
         }
         else
             _dev->issue_stream_cmd(uhd::stream_cmd_t::STREAM_MODE_STOP_CONTINUOUS);
diff --git a/gr-uhd/lib/uhd_mimo_source.h b/gr-uhd/lib/uhd_mimo_source.h
index 916f50972..e234779df 100644
--- a/gr-uhd/lib/uhd_mimo_source.h
+++ b/gr-uhd/lib/uhd_mimo_source.h
@@ -114,6 +114,12 @@ public:
     virtual std::vector<std::string> get_antennas(size_t chan) = 0;
 
     /*!
+     * Get the current time registers.
+     * \return the current usrp time
+     */
+    virtual uhd::time_spec_t get_time_now(void) = 0;
+
+    /*!
      * Set the time registers at the next pps (across all mboards).
      * \param time_spec the new time
      */
diff --git a/gr-uhd/lib/uhd_simple_sink.cc b/gr-uhd/lib/uhd_simple_sink.cc
index 1443490cd..d4bb7d437 100644
--- a/gr-uhd/lib/uhd_simple_sink.cc
+++ b/gr-uhd/lib/uhd_simple_sink.cc
@@ -95,6 +95,10 @@ public:
         return _dev->set_clock_config(clock_config);
     }
 
+    uhd::time_spec_t get_time_now(void){
+        return _dev->get_time_now();
+    }
+
     void set_time_now(const uhd::time_spec_t &time_spec){
         return _dev->set_time_now(time_spec);
     }
diff --git a/gr-uhd/lib/uhd_simple_sink.h b/gr-uhd/lib/uhd_simple_sink.h
index aad90d098..7f1596259 100644
--- a/gr-uhd/lib/uhd_simple_sink.h
+++ b/gr-uhd/lib/uhd_simple_sink.h
@@ -111,6 +111,12 @@ public:
     virtual void set_clock_config(const uhd::clock_config_t &clock_config) = 0;
 
     /*!
+     * Get the current time registers.
+     * \return the current usrp time
+     */
+    virtual uhd::time_spec_t get_time_now(void) = 0;
+
+    /*!
      * Set the time registers asap.
      * \param time_spec the new time
      */
diff --git a/gr-uhd/lib/uhd_simple_source.cc b/gr-uhd/lib/uhd_simple_source.cc
index c680aa313..c734e9244 100644
--- a/gr-uhd/lib/uhd_simple_source.cc
+++ b/gr-uhd/lib/uhd_simple_source.cc
@@ -96,6 +96,10 @@ public:
         return _dev->set_clock_config(clock_config);
     }
 
+    uhd::time_spec_t get_time_now(void){
+        return _dev->get_time_now();
+    }
+
     void set_time_now(const uhd::time_spec_t &time_spec){
         return _dev->set_time_now(time_spec);
     }
diff --git a/gr-uhd/lib/uhd_simple_source.h b/gr-uhd/lib/uhd_simple_source.h
index 06e4d2431..8568fc2d4 100644
--- a/gr-uhd/lib/uhd_simple_source.h
+++ b/gr-uhd/lib/uhd_simple_source.h
@@ -111,6 +111,12 @@ public:
     virtual void set_clock_config(const uhd::clock_config_t &clock_config) = 0;
 
     /*!
+     * Get the current time registers.
+     * \return the current usrp time
+     */
+    virtual uhd::time_spec_t get_time_now(void) = 0;
+
+    /*!
      * Set the time registers asap.
      * \param time_spec the new time
      */