Create doppler shift correction block

grc/CMakeLists.txt

@@ -28,5 +28,6 @@ install(FILES
     satnogs_ax25_decoder_b.xml
     satnogs_udp_msg_source.xml
     satnogs_debug_msg_source.xml
-    satnogs_tcp_rigctl_msg_source.xml DESTINATION share/gnuradio/grc/blocks
+    satnogs_tcp_rigctl_msg_source.xml
+    satnogs_doppler_correction_cc.xml DESTINATION share/gnuradio/grc/blocks
 )

grc/satnogs_doppler_correction_cc.xml

@@ -0,0 +1,38 @@
+<?xml version="1.0"?>
+<block>
+  <name>doppler_correction_cc</name>
+  <key>satnogs_doppler_correction_cc</key>
+  <category>satnogs</category>
+  <import>import satnogs</import>
+  <make>satnogs.doppler_correction_cc($target_freq)</make>
+  <!-- Make one 'param' node for every Parameter you want settable from the GUI.
+       Sub-nodes:
+       * name
+       * key (makes the value accessible as $keyname, e.g. in the make node)
+       * type -->
+  <param>
+    <name>...</name>
+    <key>...</key>
+    <type>...</type>
+  </param>
+
+  <!-- Make one 'sink' node per input. Sub-nodes:
+       * name (an identifier for the GUI)
+       * type
+       * vlen
+       * optional (set to 1 for optional inputs) -->
+  <sink>
+    <name>in</name>
+    <type><!-- e.g. int, float, complex, byte, short, xxx_vector, ...--></type>
+  </sink>
+
+  <!-- Make one 'source' node per output. Sub-nodes:
+       * name (an identifier for the GUI)
+       * type
+       * vlen
+       * optional (set to 1 for optional inputs) -->
+  <source>
+    <name>out</name>
+    <type><!-- e.g. int, float, complex, byte, short, xxx_vector, ...--></type>
+  </source>
+</block>

include/satnogs/CMakeLists.txt

@@ -40,5 +40,6 @@ install(FILES
     udp_msg_source.h
     debug_msg_source.h
     tc_tm.h
-    tcp_rigctl_msg_source.h DESTINATION include/satnogs
+    tcp_rigctl_msg_source.h
+    doppler_correction_cc.h DESTINATION include/satnogs
 )

include/satnogs/doppler_correction_cc.h

@@ -0,0 +1,66 @@
+/* -*- c++ -*- */
+/*
+ * gr-satnogs: SatNOGS GNU Radio Out-Of-Tree Module
+ *
+ *  Copyright (C) 2016, Libre Space Foundation <http://librespacefoundation.org/>
+ *
+ *  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/>.
+ */
+
+#ifndef INCLUDED_SATNOGS_DOPPLER_CORRECTION_CC_H
+#define INCLUDED_SATNOGS_DOPPLER_CORRECTION_CC_H
+
+#include <satnogs/api.h>
+#include <gnuradio/sync_block.h>
+
+namespace gr
+{
+  namespace satnogs
+  {
+
+    /*!
+     * \brief This block corrects the doppler effect between the ground
+     * station and the satellite. It takes the imput stream in baseband
+     * and applies proper corrections to keep the carrier at the desired
+     * frequency. To achieve that it uses messages containing the absolute
+     * predicted frequency of the satellite from software like Gpredict.
+     *
+     * \ingroup satnogs
+     *
+     */
+    class SATNOGS_API doppler_correction_cc : virtual public gr::sync_block
+    {
+    public:
+      typedef boost::shared_ptr<doppler_correction_cc> sptr;
+
+      /*!
+       * The doppler correction block. The input is the complex signal at
+       * baseband as it comes from the SDR device. The message input \p freq
+       * received periodically messages containing the predicted absolute
+       * frequency of the satellite at the moment of the
+       * @param target_freq the absolute frequency of the satellite
+       * @param sampling_rate the sampling rate of the signal
+       * @param corrections_per_sec the number of the corrections every second
+       * that the block should perform
+       */
+      static sptr
+      make (double target_freq, double sampling_rate,
+	    size_t corrections_per_sec = 1000);
+    };
+
+  } // namespace satnogs
+} // namespace gr
+
+#endif /* INCLUDED_SATNOGS_DOPPLER_CORRECTION_CC_H */
+

lib/CMakeLists.txt

@@ -37,7 +37,8 @@ list(APPEND satnogs_sources
     ax25_decoder_b_impl.cc
     udp_msg_source_impl.cc
     debug_msg_source_impl.cc
-    tcp_rigctl_msg_source_impl.cc )
+    tcp_rigctl_msg_source_impl.cc
+    doppler_correction_cc_impl.cc )
 
 set(satnogs_sources "${satnogs_sources}" PARENT_SCOPE)
 if(NOT satnogs_sources)

lib/doppler_correction_cc_impl.cc

@@ -0,0 +1,84 @@
+/* -*- c++ -*- */
+/*
+ * gr-satnogs: SatNOGS GNU Radio Out-Of-Tree Module
+ *
+ *  Copyright (C) 2016, Libre Space Foundation <http://librespacefoundation.org/>
+ *
+ *  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/>.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <gnuradio/io_signature.h>
+#include "doppler_correction_cc_impl.h"
+
+namespace gr
+{
+  namespace satnogs
+  {
+
+    doppler_correction_cc::sptr
+    doppler_correction_cc::make (double target_freq, double sampling_rate,
+				 size_t corrections_per_sec)
+    {
+      return gnuradio::get_initial_sptr (
+	  new doppler_correction_cc_impl (target_freq, sampling_rate,
+					  corrections_per_sec));
+    }
+
+    /*
+     * The private constructor
+     */
+    doppler_correction_cc_impl::doppler_correction_cc_impl (
+	double target_freq, double sampling_rate, size_t corrections_per_sec) :
+	    gr::sync_block ("doppler_correction_cc",
+			    gr::io_signature::make (1, 1, sizeof(gr_complex)),
+			    gr::io_signature::make (1, 1, sizeof(gr_complex))),
+	    d_target_freq (target_freq),
+	    d_samp_rate (sampling_rate),
+	    d_update_period (sampling_rate / (double) corrections_per_sec),
+	    d_freq_diff (0.0)
+    {
+      message_port_register_in (pmt::mp ("freq"));
+      /*
+       * Set the maximum number of samples to be equivalent of half a second.
+       * With this way we are sure that at least one frequency message
+       * per second will be processed.
+       */
+      set_max_noutput_items (d_samp_rate / 2.0);
+    }
+
+    /*
+     * Our virtual destructor.
+     */
+    doppler_correction_cc_impl::~doppler_correction_cc_impl ()
+    {
+    }
+
+    int
+    doppler_correction_cc_impl::work (int noutput_items,
+				      gr_vector_const_void_star &input_items,
+				      gr_vector_void_star &output_items)
+    {
+      const gr_complex *in = (const gr_complex *) input_items[0];
+      gr_complex *out = (gr_complex *) output_items[0];
+
+      return noutput_items;
+    }
+
+  } /* namespace satnogs */
+} /* namespace gr */
+

lib/doppler_correction_cc_impl.h

@@ -0,0 +1,55 @@
+/* -*- c++ -*- */
+/*
+ * gr-satnogs: SatNOGS GNU Radio Out-Of-Tree Module
+ *
+ *  Copyright (C) 2016, Libre Space Foundation <http://librespacefoundation.org/>
+ *
+ *  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/>.
+ */
+
+#ifndef INCLUDED_SATNOGS_DOPPLER_CORRECTION_CC_IMPL_H
+#define INCLUDED_SATNOGS_DOPPLER_CORRECTION_CC_IMPL_H
+
+#include <satnogs/doppler_correction_cc.h>
+
+namespace gr
+{
+  namespace satnogs
+  {
+
+    class doppler_correction_cc_impl : public doppler_correction_cc
+    {
+    private:
+      const double d_target_freq;
+      const double d_samp_rate;
+      const double d_update_period;
+
+      double d_freq_diff;
+
+    public:
+      doppler_correction_cc_impl (double target_freq, double sampling_rate,
+				  size_t corrections_per_sec);
+      ~doppler_correction_cc_impl ();
+
+      // Where all the action really happens
+      int
+      work (int noutput_items, gr_vector_const_void_star &input_items,
+	    gr_vector_void_star &output_items);
+    };
+
+  } // namespace satnogs
+} // namespace gr
+
+#endif /* INCLUDED_SATNOGS_DOPPLER_CORRECTION_CC_IMPL_H */
+

swig/satnogs_swig.i

@@ -22,6 +22,7 @@
 #include "satnogs/udp_msg_source.h"
 #include "satnogs/debug_msg_source.h"
 #include "satnogs/tcp_rigctl_msg_source.h"
+#include "satnogs/doppler_correction_cc.h"
 %}
 
 
@@ -50,3 +51,5 @@ GR_SWIG_BLOCK_MAGIC2(satnogs, udp_msg_source);
 GR_SWIG_BLOCK_MAGIC2(satnogs, debug_msg_source);
 %include "satnogs/tcp_rigctl_msg_source.h"
 GR_SWIG_BLOCK_MAGIC2(satnogs, tcp_rigctl_msg_source);
+%include "satnogs/doppler_correction_cc.h"
+GR_SWIG_BLOCK_MAGIC2(satnogs, doppler_correction_cc);