Add moving average for battery values in OBPSensorTask

lib/obp60task/movingAvg.cpp

@@ -0,0 +1,67 @@
+// Arduino Moving Average Library
+// https://github.com/JChristensen/movingAvg
+// Copyright (C) 2018 by Jack Christensen and licensed under
+// GNU GPL v3.0, https://www.gnu.org/licenses/gpl.html
+
+#include <movingAvg.h>
+
+// initialize - allocate the interval array
+void movingAvg::begin()
+{
+    m_readings = new int[m_interval];
+}
+
+// add a new reading and return the new moving average
+int movingAvg::reading(int newReading)
+{
+    // add each new data point to the sum until the m_readings array is filled
+    if (m_nbrReadings < m_interval) {
+        ++m_nbrReadings;
+        m_sum += newReading;
+    }
+    // once the array is filled, subtract the oldest data point and add the new one
+    else {
+        m_sum = m_sum - m_readings[m_next] + newReading;
+    }
+
+    m_readings[m_next] = newReading;
+    if (++m_next >= m_interval) m_next = 0;
+    return (m_sum + m_nbrReadings / 2) / m_nbrReadings;
+}
+
+// just return the current moving average
+int movingAvg::getAvg()
+{
+    return (m_sum + m_nbrReadings / 2) / m_nbrReadings;
+}
+
+// return the average for a subset of the data, the most recent nPoints readings.
+// for invalid values of nPoints, return zero.
+int movingAvg::getAvg(int nPoints)
+{
+    if (nPoints < 1 || nPoints > m_interval || nPoints > m_nbrReadings) {
+        return 0;
+    }
+    else {
+        long sum{0};
+        int i = m_next;
+        for (int n=0; n<nPoints; ++n) {
+            if (i == 0) {
+                i = m_interval - 1;
+            }
+            else {
+                --i;
+            }
+            sum += m_readings[i];
+        }
+        return (sum + nPoints / 2) / nPoints;
+    }
+}
+
+// start the moving average over again
+void movingAvg::reset()
+{
+    m_nbrReadings = 0;
+    m_sum = 0;
+    m_next = 0;
+}