added https://playground.arduino.cc/Main/RunningAverage

diff --git a/wlan_si/RunningAverage.cpp b/wlan_si/RunningAverage.cpp
new file mode 100644 (file)
index 0000000..f72d90a
--- /dev/null
+++ b/wlan_si/RunningAverage.cpp
@@ -0,0 +1,85 @@
+//
+//    FILE: RunningAverage.cpp
+//  AUTHOR: Rob Tillaart
+// VERSION: 0.2.04
+// PURPOSE: RunningAverage library for Arduino
+//
+// The library stores the last N individual values in a circular buffer,
+// to calculate the running average.
+//
+// HISTORY:
+// 0.1.00 - 2011-01-30 initial version
+// 0.1.01 - 2011-02-28 fixed missing destructor in .h
+// 0.2.00 - 2012-??-?? Yuval Naveh added trimValue (found on web)
+//          http://stromputer.googlecode.com/svn-history/r74/trunk/Arduino/Libraries/RunningAverage/RunningAverage.cpp
+// 0.2.01 - 2012-11-21 refactored
+// 0.2.02 - 2012-12-30 refactored trimValue -> fillValue
+// 0.2.03 - 2013-11-31 getElement
+// 0.2.04 - 2014-07-03 added memory protection
+//
+// Released to the public domain
+//
+
+#include "RunningAverage.h"
+#include <stdlib.h>
+
+RunningAverage::RunningAverage(int n)
+{
+    _size = n;
+    _ar = (float*) malloc(_size * sizeof(float));
+    if (_ar == NULL) _size = 0;
+    clear();
+}
+
+RunningAverage::~RunningAverage()
+{
+    if (_ar != NULL) free(_ar);
+}
+
+// resets all counters
+void RunningAverage::clear()
+{
+    _cnt = 0;
+    _idx = 0;
+    _sum = 0.0;
+    for (int i = 0; i< _size; i++) _ar[i] = 0.0;  // needed to keep addValue simple
+}
+
+// adds a new value to the data-set
+void RunningAverage::addValue(float f)
+{
+    if (_ar == NULL) return;
+    _sum -= _ar[_idx];
+    _ar[_idx] = f;
+    _sum += _ar[_idx];
+    _idx++;
+    if (_idx == _size) _idx = 0;  // faster than %
+    if (_cnt < _size) _cnt++;
+}
+
+// returns the average of the data-set added sofar
+float RunningAverage::getAverage()
+{
+    if (_cnt == 0) return NAN;
+    return _sum / _cnt;
+}
+
+// returns the value of an element if exist, 0 otherwise
+float RunningAverage::getElement(uint8_t idx)
+{
+    if (idx >=_cnt ) return NAN;
+    return _ar[idx];
+}
+
+// fill the average with a value
+// the param number determines how often value is added (weight)
+// number should preferably be between 1 and size
+void RunningAverage::fillValue(float value, int number)
+{
+    clear();
+    for (int i = 0; i < number; i++)
+    {
+        addValue(value);
+    }
+}
+// END OF FILE

diff --git a/wlan_si/RunningAverage.h b/wlan_si/RunningAverage.h
new file mode 100644 (file)
index 0000000..7a400a4
--- /dev/null
+++ b/wlan_si/RunningAverage.h
@@ -0,0 +1,48 @@
+#ifndef RunningAverage_h
+#define RunningAverage_h
+//
+//    FILE: RunningAverage.h
+//  AUTHOR: Rob dot Tillaart at gmail dot com
+// PURPOSE: RunningAverage library for Arduino
+//     URL: http://arduino.cc/playground/Main/RunningAverage
+// HISTORY: See RunningAverage.cpp
+//
+// Released to the public domain
+//
+
+// backwards compatibility
+// clr() clear()
+// add(x) addValue(x)
+// avg() getAverage()
+
+#define RUNNINGAVERAGE_LIB_VERSION "0.2.04"
+
+#include "Arduino.h"
+
+class RunningAverage
+{
+public:
+    RunningAverage(void);
+    RunningAverage(int);
+    ~RunningAverage();
+
+    void clear();
+    void addValue(float);
+    void fillValue(float, int);
+
+    float getAverage();
+
+    float getElement(uint8_t idx);
+    uint8_t getSize() { return _size; }
+    uint8_t getCount() { return _cnt; }
+
+protected:
+    uint8_t _size;
+    uint8_t _cnt;
+    uint8_t _idx;
+    float   _sum;
+    float * _ar;
+};
+
+#endif
+// END OF FILE

diff --git a/wlan_si/wlan_si.ino b/wlan_si/wlan_si.ino
index 2c12d93..ffb9f4e 100644 (file)
--- a/wlan_si/wlan_si.ino
+++ b/wlan_si/wlan_si.ino
@@ -9,23 +9,10 @@ int pir = 6; // PIR on d6
 // hardware based on https://dev.wlan-si.net/wiki/Telemetry/sensgw
 // original software https://github.com/SloMusti/sensgw
 
-float runningAverage(float M) {
-  #define LM_SIZE 100
-  static float LM[LM_SIZE];      // LastMeasurements
-  static byte index = 0;
-  static float sum = 0;
-  static byte count = 0;
-
-  // keep sum updated to improve speed.
-  sum -= LM[index];
-  LM[index] = M;
-  sum += LM[index];
-  index++;
-  index = index % LM_SIZE;
-  if (count < LM_SIZE) count++;
-
-  return sum / count;
-}
+#include "RunningAverage.h"
+
+RunningAverage pressureKPA_avg(100);
+RunningAverage temperatureC_avg(100);
 
 void setup(void) 
 {
@@ -48,10 +35,12 @@ void loop(void)
   float pressureKPA = 0, temperatureC = 0;    
 
   mpl115a2.getPT(&pressureKPA,&temperatureC);
+  pressureKPA_avg.addValue(pressureKPA);
+  temperatureC_avg.addValue(temperatureC);
 
   if ( count++ % 10 == 0 ) {
-  Serial.print("Pressure="); Serial.print(runningAverage(pressureKPA), 4); Serial.print(" kPa ");
-  Serial.print("Temp="); Serial.print(temperatureC, 1); Serial.print(" C");
+  Serial.print("Pressure="); Serial.print(pressureKPA_avg.getAverage(), 4); Serial.print(" kPa ");
+  Serial.print("Temp="); Serial.print(temperatureC_avg.getAverage(), 2); Serial.print(" C");
 
   Serial.print(" PIR="); Serial.print( digitalRead(pir) );
 
@@ -59,8 +48,6 @@ void loop(void)
 
   Serial.println();
 
-  } else {
-       runningAverage(pressureKPA);
   }
 
   digitalWrite(led, LOW);