hackrf: implement BB lowpass filter control

To use the default (automatic) bandwidth filter selection, this should
be set to 0.

grc/gen_osmosdr_blocks.py

@@ -37,9 +37,8 @@ self.\$(id).set_gain_mode(\$gain_mode$(n), $n)
 self.\$(id).set_gain(\$gain$(n), $n)
 self.\$(id).set_if_gain(\$if_gain$(n), $n)
 self.\$(id).set_bb_gain(\$bb_gain$(n), $n)
-\#if \$ant$(n)()
 self.\$(id).set_antenna(\$ant$(n), $n)
-\#end if
+self.\$(id).set_bandwidth(\$bw$(n), $n)
 \#end if
 #end for
   </make>
@@ -53,6 +52,7 @@ self.\$(id).set_antenna(\$ant$(n), $n)
   <callback>set_if_gain(\$if_gain$(n), $n)</callback>
   <callback>set_bb_gain(\$bb_gain$(n), $n)</callback>
   <callback>set_antenna(\$ant$(n), $n)</callback>
+  <callback>set_bandwidth(\$bw$(n), $n)</callback>
   #end for
   <param>
     <name>$(dir.title())put Type</name>
@@ -183,6 +183,9 @@ Antenna:
 For devices with only one antenna, this may be left blank.
 Otherwise, the user should specify one of the possible antenna choices.
 
+Bandwidth:
+Set the bandpass filter on the radio frontend. To use the default (automatic) bandwidth filter setting, this should be zero.
+
 See the OsmoSDR project page for more detailed documentation:
 http://sdr.osmocom.org/trac/
 http://sdr.osmocom.org/trac/wiki/rtl-sdr
@@ -276,6 +279,21 @@ PARAMS_TMPL = """
       \#end if
     </hide>
   </param>
+  <param>
+    <name>Ch$(n): Bandwidth (Hz)</name>
+    <key>bw$(n)</key>
+    <value>0</value>
+    <type>real</type>
+    <hide>
+      \#if not \$nchan() > $n
+        all
+      \#elif \$bw$(n)()
+        none
+      \#else
+        part
+      \#end if
+    </hide>
+  </param>
 """
 
 def parse_tmpl(_tmpl, **kwargs):

include/osmosdr/osmosdr_source_c.h

@@ -263,6 +263,27 @@ public:
    */
   virtual void set_iq_balance( const std::complex<double> &correction,
                                size_t chan = 0 ) = 0;
+
+  /*!
+   * Set the bandpass filter on the radio frontend.
+   * \param bandwidth the filter bandwidth in Hz
+   * \param chan the channel index 0 to N-1
+   * \return the actual filter bandwidth in Hz
+   */
+  virtual double set_bandwidth( double bandwidth, size_t chan = 0 ) = 0;
+
+  /*!
+   * Get the actual bandpass filter setting on the radio frontend.
+   * \param chan the channel index 0 to N-1
+   * \return the actual filter bandwidth in Hz
+   */
+  virtual double get_bandwidth( size_t chan = 0 ) = 0;
+
+  /*!
+   * Get the possible bandpass filter settings on the radio frontend.
+   * \return a range of bandwidths in Hz
+   */
+  virtual osmosdr::meta_range_t get_bandwidth_range( size_t chan = 0 ) = 0;
 };
 
 #endif /* INCLUDED_OSMOSDR_SOURCE_C_H */

lib/hackrf/hackrf_source_c.cc

@@ -625,13 +625,13 @@ std::string hackrf_source_c::get_antenna( size_t chan )
   return "ANT";
 }
 
-void hackrf_source_c::set_bandwidth( double bandwidth, size_t chan )
+double hackrf_source_c::set_bandwidth( double bandwidth, size_t chan )
 {
   int ret;
 //  osmosdr::meta_range_t bandwidths = get_bandwidth_range( chan );
 
-  if ( bandwidth == 0.0 )
+  if ( bandwidth == 0.0 ) /* bandwidth of 0 means automatic filter selection */
-    return;
+    bandwidth = _sample_rate;
 
   if ( _dev ) {
     /* compute best default value depending on sample rate (auto filter) */
@@ -643,6 +643,8 @@ void hackrf_source_c::set_bandwidth( double bandwidth, size_t chan )
       throw std::runtime_error( std::string( __FUNCTION__ ) );
     }
   }
+
+  return _bandwidth;
 }
 
 double hackrf_source_c::get_bandwidth( size_t chan )

lib/hackrf/hackrf_source_c.h

@@ -113,7 +113,7 @@ private:
   std::string set_antenna( const std::string & antenna, size_t chan = 0 );
   std::string get_antenna( size_t chan = 0 );
 
-  void set_bandwidth( double bandwidth, size_t chan = 0 );
+  double set_bandwidth( double bandwidth, size_t chan = 0 );
   double get_bandwidth( size_t chan = 0 );
   osmosdr::meta_range_t get_bandwidth_range( size_t chan = 0 );
 

lib/osmosdr_source_c_impl.cc

@@ -561,8 +561,8 @@ double osmosdr_source_c_impl::set_bb_gain( double gain, size_t chan )
   BOOST_FOREACH( osmosdr_src_iface *dev, _devs )
     for (size_t dev_chan = 0; dev_chan < dev->get_num_channels(); dev_chan++)
       if ( chan == channel++ )
-        if ( _if_gain[ chan ] != gain ) {
+        if ( _bb_gain[ chan ] != gain ) {
-          _if_gain[ chan ] = gain;
+          _bb_gain[ chan ] = gain;
           return dev->set_bb_gain( gain, dev_chan );
         }
 
@@ -662,3 +662,39 @@ void osmosdr_source_c_impl::set_iq_balance( const std::complex<double> &correcti
   }
 #endif
 }
+
+double osmosdr_source_c_impl::set_bandwidth( double bandwidth, size_t chan )
+{
+  size_t channel = 0;
+  BOOST_FOREACH( osmosdr_src_iface *dev, _devs )
+    for (size_t dev_chan = 0; dev_chan < dev->get_num_channels(); dev_chan++)
+      if ( chan == channel++ )
+        if ( _bandwidth[ chan ] != bandwidth ) {
+          _bandwidth[ chan ] = bandwidth;
+          return dev->set_bandwidth( bandwidth, dev_chan );
+        }
+
+  return 0;
+}
+
+double osmosdr_source_c_impl::get_bandwidth( size_t chan )
+{
+  size_t channel = 0;
+  BOOST_FOREACH( osmosdr_src_iface *dev, _devs )
+    for (size_t dev_chan = 0; dev_chan < dev->get_num_channels(); dev_chan++)
+      if ( chan == channel++ )
+        return dev->get_bandwidth( dev_chan );
+
+  return 0;
+}
+
+osmosdr::meta_range_t osmosdr_source_c_impl::get_bandwidth_range( size_t chan )
+{
+  size_t channel = 0;
+  BOOST_FOREACH( osmosdr_src_iface *dev, _devs )
+    for (size_t dev_chan = 0; dev_chan < dev->get_num_channels(); dev_chan++)
+      if ( chan == channel++ )
+        return dev->get_bandwidth_range( dev_chan );
+
+  return osmosdr::meta_range_t();
+}

lib/osmosdr_source_c_impl.h

@@ -66,6 +66,10 @@ public:
   void set_iq_balance_mode( int mode, size_t chan = 0 );
   void set_iq_balance( const std::complex<double> &correction, size_t chan = 0 );
 
+  double set_bandwidth( double bandwidth, size_t chan = 0 );
+  double get_bandwidth( size_t chan = 0 );
+  osmosdr::meta_range_t get_bandwidth_range( size_t chan = 0 );
+
 private:
   osmosdr_source_c_impl (const std::string & args);  	// private constructor
 
@@ -73,19 +77,22 @@ private:
   // access the private constructor.
   friend osmosdr_source_c_sptr osmosdr_make_source_c (const std::string & args);
 
+  std::vector< osmosdr_src_iface * > _devs;
+
   double _sample_rate;
   std::map< size_t, double > _center_freq;
   std::map< size_t, double > _freq_corr;
   std::map< size_t, bool > _gain_mode;
   std::map< size_t, double > _gain;
   std::map< size_t, double > _if_gain;
+  std::map< size_t, double > _bb_gain;
   std::map< size_t, std::string > _antenna;
-  std::vector< osmosdr_src_iface * > _devs;
 #ifdef HAVE_IQBALANCE
   std::vector< iqbalance_fix_cc * > _iq_fix;
   std::vector< iqbalance_optimize_c * > _iq_opt;
   std::map< size_t, std::pair<float, float> > _vals;
 #endif
+  std::map< size_t, double > _bandwidth;
 };
 
 #endif /* INCLUDED_OSMOSDR_SOURCE_C_IMPL_H */

lib/osmosdr_src_iface.h

@@ -216,6 +216,47 @@ public:
    * \return the actual antenna's name
    */
   virtual std::string get_antenna( size_t chan = 0 ) = 0;
+
+  /*!
+   * Set the RX frontend IQ balance mode.
+   *
+   * \param mode iq balance correction mode: 0 = Off, 1 = Manual, 2 = Automatic
+   * \param chan the channel index 0 to N-1
+   */
+  virtual void set_iq_balance_mode( int mode, size_t chan = 0 )
+    { return; }
+
+  /*!
+   * Set the RX frontend IQ balance correction.
+   * Use this to adjust the magnitude and phase of I and Q.
+   *
+   * \param correction the complex correction value
+   * \param chan the channel index 0 to N-1
+   */
+  virtual void set_iq_balance( const std::complex<double> &correction, size_t chan = 0 )
+    { return; }
+
+  /*!
+   * Set the bandpass filter on the radio frontend.
+   * \param bandwidth the filter bandwidth in Hz
+   * \param chan the channel index 0 to N-1
+   * \return the actual filter bandwidth in Hz
+   */
+  virtual double set_bandwidth( double bandwidth, size_t chan = 0 ) { return 0; }
+
+  /*!
+   * Get the actual bandpass filter setting on the radio frontend.
+   * \param chan the channel index 0 to N-1
+   * \return the actual filter bandwidth in Hz
+   */
+  virtual double get_bandwidth( size_t chan = 0 ) { return 0; }
+
+  /*!
+   * Get the possible bandpass filter settings on the radio frontend.
+   * \return a range of bandwidths in Hz
+   */
+  virtual osmosdr::meta_range_t get_bandwidth_range( size_t chan = 0 )
+      { return osmosdr::meta_range_t(); }
 };
 
 #endif // OSMOSDR_SRC_IFACE_H