filter: add variable_low_pass_filter_taps

Convenience block in GRC to generate taps using
firdes.low_pass(...)

3 files changed, 79 insertions, 1 deletions

diff --git a/gr-filter/grc/CMakeLists.txt b/gr-filter/grc/CMakeLists.txt
index 575f6675d..2f7aa8ad8 100644
--- a/gr-filter/grc/CMakeLists.txt
+++ b/gr-filter/grc/CMakeLists.txt
@@ -45,6 +45,7 @@ install(FILES
     filter_band_pass_filter.xml
     filter_band_reject_filter.xml
     filter_root_raised_cosine_filter.xml
+    variable_low_pass_filter_taps.xml
     DESTINATION ${GRC_BLOCKS_DIR}
     COMPONENT "filter_python"
 )
diff --git a/gr-filter/grc/filter_block_tree.xml b/gr-filter/grc/filter_block_tree.xml
index fbba9daf0..1c6eaa5e8 100644
--- a/gr-filter/grc/filter_block_tree.xml
+++ b/gr-filter/grc/filter_block_tree.xml
@@ -1,7 +1,7 @@
 <?xml version="1.0"?>
 
 <!--
- Copyright 2012 Free Software Foundation, Inc.
+ Copyright 2012,2015 Free Software Foundation, Inc.
 
  This file is part of GNU Radio
 
@@ -30,6 +30,8 @@
    <name></name> <!-- Blank for Root Name -->
    <cat>
       <name>Filters</name>
+      <!-- FIR filter tap generators -->
+      <block>variable_low_pass_filter_taps</block>
       <!-- FIR convenience filters -->
       <block>low_pass_filter</block>
       <block>high_pass_filter</block>
diff --git a/gr-filter/grc/variable_low_pass_filter_taps.xml b/gr-filter/grc/variable_low_pass_filter_taps.xml
new file mode 100644
index 000000000..e3367b1ec
--- /dev/null
+++ b/gr-filter/grc/variable_low_pass_filter_taps.xml
@@ -0,0 +1,75 @@
+<?xml version="1.0"?>
+<!--
+######################################################
+## Convenience wrapper around call to fides.low_pass()
+######################################################
+ -->
+<block>
+  <name>Low-pass Filter Taps</name>
+  <key>variable_low_pass_filter_taps</key>
+  <import>from gnuradio.filter import firdes</import>
+  <var_make>
+self.$(id) = $(id) = firdes.low_pass($gain, $samp_rate, $cutoff_freq, $width, $win, $beta)
+  </var_make>
+  <var_value>firdes.low_pass($gain, $samp_rate, $cutoff_freq, $width, $win, $beta)</var_value>
+  <make></make>
+  <param>
+    <name>Gain</name>
+    <key>gain</key>
+    <value>1.0</value>
+    <type>float</type>
+  </param>
+  <param>
+    <name>Sample Rate (Hz)</name>
+    <key>samp_rate</key>
+    <value>samp_rate</value>
+    <type>float</type>
+  </param>
+  <param>
+    <name>Cutoff Freq (Hz)</name>
+    <key>cutoff_freq</key>
+    <type>float</type>
+  </param>
+  <param>
+    <name>Transition Width (Hz)</name>
+    <key>width</key>
+    <type>float</type>
+  </param>
+  <param>
+    <name>Window</name>
+    <key>win</key>
+    <value>firdes.WIN_HAMMING</value>
+    <type>int</type>
+    <option>
+      <name>Hamming</name>
+      <key>firdes.WIN_HAMMING</key>
+    </option>
+    <option>
+      <name>Hann</name>
+      <key>firdes.WIN_HANN</key>
+    </option>
+    <option>
+      <name>Blackman</name>
+      <key>firdes.WIN_BLACKMAN</key>
+    </option>
+    <option>
+      <name>Rectangular</name>
+      <key>firdes.WIN_RECTANGULAR</key>
+    </option>
+    <option>
+      <name>Kaiser</name>
+      <key>firdes.WIN_KAISER</key>
+    </option>
+  </param>
+  <param>
+    <name>Beta</name>
+    <key>beta</key>
+    <value>6.76</value>
+    <type>float</type>
+  </param>
+  <doc>
+    This variable is a convenience wrapper around a call to firdes.low_pass(...).
+
+    The beta paramater only applies to the Kaiser window.
+  </doc>
+</block>