Michael Shimniok / SimpleFilter

Implements a simple leaky integrator integer value filter, handy for fast, simple, ADC output filtering. Implemented as described here: [[http://ece124web.groups.et.byu.net/references/readings/Simple%20Software%20Lowpass%20Filter.pdf|Simple Software Lowpass Filter.pdf]]

Dependents:   AVC_20110423 WallBot_Simple AVC_2012

Files at this revision

API Documentation at this revision

Revision 1:70348515ed2f, committed 2011-04-20

Comitter:
shimniok
Date:
Wed Apr 20 16:57:54 2011 +0000
Parent:
0:ac15e38daeb5
Commit message:
Fixed major implementation bug. I am an idiot. :)

Changed in this revision

SimpleFilter.cpp Show annotated file Show diff for this revision Revisions of this file
SimpleFilter.h Show annotated file Show diff for this revision Revisions of this file 
diff -r ac15e38daeb5 -r 70348515ed2f SimpleFilter.cpp
--- a/SimpleFilter.cpp	Wed Apr 20 08:00:25 2011 +0000
+++ b/SimpleFilter.cpp	Wed Apr 20 16:57:54 2011 +0000
@@ -6,8 +6,11 @@
 
 short SimpleFilter::filter(short value) {
 
-    _filter_value += value - (_filter_value >> _shift);
-    _filter_value >>= _shift;
+    _filter_value += (value - (_filter_value >> _shift));
     
-    return _filter_value;
-}
\ No newline at end of file
+    return _filter_value >> _shift;
+}
+
+short SimpleFilter::value(void) {
+    return _filter_value >> _shift;
+}

diff -r ac15e38daeb5 -r 70348515ed2f SimpleFilter.h
--- a/SimpleFilter.h	Wed Apr 20 08:00:25 2011 +0000
+++ b/SimpleFilter.h	Wed Apr 20 16:57:54 2011 +0000
@@ -21,6 +21,18 @@
      */
     short filter(short value);
 
+    /** Read the current value in the filter
+     *
+     * @returns the current value in the filter
+     */
+    short value(void);
+
+    /** Shorthand operator for value()
+     *
+     * @returns the current value in the filter
+     */
+    operator short() { return value(); }
+
 private:
     long _filter_value;
     short _shift;