Add smoothing option for any chart plot

lib/obp60task/OBPcharts.cpp

@@ -42,6 +42,11 @@ Chart::Chart(RingBuffer<uint16_t>& dataBuf, double dfltRng, CommonData& common,
     dbMAX_VAL = dataBuf.getMaxVal();
     bufSize = dataBuf.getCapacity();
 
+    smoothCharts = common.config->getBool(common.config->smoothCharts);
+    if (smoothCharts) {
+        chrtAvg.begin();
+    }
+
     // Initialize chart data format; shorter version of standard format indicator
     if (dbFormat == "formatCourse" || dbFormat == "formatWind" || dbFormat == "formatRot") {
         chrtDataFmt = WIND; // Chart is showing data of course / wind <degree> format
@@ -337,6 +342,23 @@ void Chart::drawChartLines(const char direction, const int8_t chrtIntv, const do
     double chrtVal; // Current data value
     Pos point, prevPoint; // current and previous chart point
 
+    if (smoothCharts) {
+        // prime moving average filter to ensure the first plotted point is already averaged
+
+        chrtAvg.reset();
+
+        // Feed the filter the 10 values preceding bufStart
+        for (int p = 10; p > 0; p--) {
+            // Calculate index with wrapping: (start - offset + size) % size
+            int primeIdx = (bufStart - (p * chrtIntv));
+            double primeVal = dataBuf.get(primeIdx);
+            
+            if (primeVal != dbMAX_VAL) {
+                chrtAvg.reading(primeVal);
+            }
+        }
+    }
+
     for (int i = 0; i < (numBufVals / chrtIntv); i++) {
 
         chrtVal = dataBuf.get(bufStart + (i * chrtIntv)); // show the latest wind values in buffer; keep 1st value constant in a rolling buffer
@@ -345,6 +367,11 @@ void Chart::drawChartLines(const char direction, const int8_t chrtIntv, const do
             chrtPrevVal = dbMAX_VAL;
         } else {
 
+            if (smoothCharts) {
+                // if chart lines shall be smoothed, apply moving average filter of the last 10 values
+                chrtVal = chrtAvg.reading(chrtVal);
+            }
+
             point = setCurrentChartPoint(i, direction, chrtVal, chrtScale);
 
             // if (i >= (numBufVals / chrtIntv) - 5) // log chart data of 1 line (adjust for test purposes)
@@ -399,7 +426,7 @@ void Chart::drawChartLines(const char direction, const int8_t chrtIntv, const do
 
             if (chrtDataFmt == WIND) { // degree of course or wind
                 recalcRngMid = true;
-                LOG_DEBUG(GwLog::DEBUG, "PageWindPlot: chart end: timAxis: %d, i: %d, bufStart: %d, numBufVals: %d, recalcRngCntr: %d", timAxis, i, bufStart, numBufVals, recalcRngMid);
+                // LOG_DEBUG(GwLog::DEBUG, "PageWindPlot: chart end: timAxis: %d, i: %d, bufStart: %d, numBufVals: %d, recalcRngCntr: %d", timAxis, i, bufStart, numBufVals, recalcRngMid);
             }
             break;
         }
@@ -454,7 +481,7 @@ void Chart::drawChrtTimeAxis(const char chrtDir, const int8_t chrtSz, const int8
     if (chrtDir == HORIZONTAL) {
         getdisplay().fillRect(0, cRoot.y, dWidth, 2, fgColor);
 
-    LOG_DEBUG(GwLog::DEBUG, "Chart::drawChrtTimeAxis: intv: %d, axSlots: %d, timAxis: %d, chrtIntv: %d", intv, axSlots, timAxis, chrtIntv);
+        // LOG_DEBUG(GwLog::DEBUG, "Chart::drawChrtTimeAxis: intv: %d, axSlots: %d, timAxis: %d, chrtIntv: %d", intv, axSlots, timAxis, chrtIntv);
         for (int j = intv; j < timAxis - 1; j += intv) { // fill time axis with values but keep area free on right hand side for value label
 
             // draw text with appropriate offset

lib/obp60task/OBPcharts.h

@@ -2,6 +2,7 @@
 #pragma once
 #include "Pagedata.h"
 #include "OBP60Extensions.h"
+#include "movingAvg.h"
 
 struct Pos {
     int x;
@@ -44,12 +45,11 @@ protected:
     static constexpr bool NO_SIMUDATA = true; // switch off simulation feature of <formatValue> function
 
     RingBuffer<uint16_t>& dataBuf; // Buffer to display
-    //char chrtDir; // Chart timeline direction: 'H' = horizontal, 'V' = vertical
-    //int8_t chrtSz; // Chart size: [0] = full size, [1] = half size left/top, [2] half size right/bottom
     double dfltRng; // Default range of chart, e.g. 30 = [0..30]
     uint16_t fgColor; // color code for any screen writing
     uint16_t bgColor; // color code for screen background
     bool useSimuData; // flag to indicate if simulation data is active
+    bool smoothCharts; // flag to indicate if charts shall be printed with smoothed gradient
     String tempFormat; // user defined format for temperature
     double zeroValue; // "0" SI value for temperature
 
@@ -84,6 +84,7 @@ protected:
     bool bufDataValid = false; // Flag to indicate if buffer data is valid
     int oldChrtIntv = 0; // remember recent user selection of data interval
 
+    movingAvg<double> chrtAvg{7}; // Store average of the last 7 chart values if chart gradient shall be smoothed
     double chrtPrevVal; // Last data value in chart area
     int x, y; // x and y coordinates for drawing
     int prevX, prevY; // Last x and y coordinates for drawing

lib/obp60task/PageWindPlot.cpp

@@ -37,7 +37,7 @@ private:
     bool oldShowTruW = false; // remember recent user selection of wind data type
 
     int8_t dataIntv = 1; // Update interval for wind history chart:
-                         // (1)|(2)|(3)|(4)|(8) x 240 seconds for 4, 8, 12, 16, 32 min. history chart
+                         // (1)|(2)|(3)|(4)|(8) seconds for up to 32 min. history chart
     bool useSimuData;
     // bool holdValues;
     String flashLED;

lib/obp60task/config_obp40.json

@@ -230,6 +230,17 @@
             "obp40": "true"
         }
     },
+    {
+        "name": "smoothCharts",
+        "label": "Smooth chart lines",
+        "type": "boolean",
+        "default": "false",
+        "description": "Print chart lines with a smoothed gradient",
+        "category": "OBP40 Settings",
+        "capabilities": {
+            "obp40": "true"
+        }
+    },
     {
         "name": "lengthFormat",
         "label": "Length Format",

lib/obp60task/config_obp60.json

@@ -230,6 +230,17 @@
             "obp60": "true"
         }
     },
+    {
+        "name": "smoothCharts",
+        "label": "Smooth chart lines",
+        "type": "boolean",
+        "default": "false",
+        "description": "Print chart lines with a smoothed gradient",
+        "category": "OBP60 Settings",
+        "capabilities": {
+            "obp40": "true"
+        }
+    },
     {
         "name": "lengthFormat",
         "label": "Length Format",