Found that problem with HRM test app was that drawing graph was takin…

…g two seconds and blocking HRM raw data readings, so disabled the graph. Added some data with fixed LED current

apps/hrmtest/app.js

@@ -30,26 +30,90 @@ var graphOriginX = 0;
 var graphOriginY = textOriginY + textH + 1;
 var graphH = screenH - textH;
 var graphW = screenW;
+var lastRawTime = 0;
 
 var HRVal = 0;          // latest HRM readings
 var HRConfidence = 0;
-var rawVals = [];     // Raw values read by i2c
-rawVals.push(0);
-var anlgVals = [];     // Raw values read from analogue pin.
-anlgVals.push(0);
-var envVals = [];     // Environment values by i2c
-envVals.push(0);
-var timeVals = [];
-timeVals.push(getTime());
-var rawBufSize = screenW;
+
+class CircBuf {
+  constructor(bufSize) {
+    this.size = bufSize;
+    this.valArr = new Array(bufSize);
+    this.idx = 0;
+
+    this.getVal = function(n) { 
+    /**
+     * Return the value stored in position n in the buffer.
+     */
+
+      let i = n + this.idx;
+      if (i>=this.valArr.length)
+          i = i - this.valArr.length;
+      return(this.valArr[i]);
+    };
+
+    this.setVal = function(val) {
+      /**
+       * Add value val to the end of the buffer
+       */
+      this.valArr[this.idx] = val;
+      this.idx++;
+      if (this.idx == this.valArr.length)
+        this.idx = 0
+    };
+
+    this.getLastVal = function() {
+      /**
+       * get the last value added to the buffer
+       */
+      if (this.idx > 0)
+        return this.valArr[this.idx-1];
+      else
+        return this.valArr[this.valArr.length -1];
+    };
+
+    this.getFirstVal = function() {
+      /**
+       * get the first value in the buffer
+       */
+      // FIXME - this is only correct once the buffer is full
+      return this.valArr[this.idx];
+    };
+
+    this.getMaxMinVals = function() {
+      /**
+       * return [minVal, maxVal] for the buffer.
+       */
+      let i = 0;
+      let minVal = this.valArr[0];
+      let maxVal = this.valArr[0];
+      for (i=0;i<this.size;i++) {
+        if (this.valArr[i]<minVal)
+          minVal = this.valArr[i];
+        if (this.valArr[i]>maxVal)
+          maxVal = this.valArr[i];
+      }
+      return [minVal, maxVal];
+    }
+  }
+}
+
+
+
+// Circular buffers to store data for plotting on the screen
+var RAW_BUF_SIZE = screenW;
+var rawBuf = new CircBuf(RAW_BUF_SIZE);
+var anlgBuf = new CircBuf(RAW_BUF_SIZE);
+var envBuf = new CircBuf(RAW_BUF_SIZE);
+var timeBuf = new CircBuf(RAW_BUF_SIZE);
+
 
 var ledCurrentVals = [0x30, 0x50, 0x5A, 0xE0];
 var ledCurrentIdx = 0;
 
 var slot0LedCurrentVal = 15;  //64
 
 
-
 function fileExists(fName){
   /**
    * Returns true if a file named by the string parameter fName exists in storage, or else 
@@ -86,15 +150,17 @@ function drawText() {
   }
   y = y + 28;
   g.setFont("6x8", 2);
-  g.drawString(rawVals[rawVals.length -1], textOriginX + 0, y);
-  g.drawString(envVals[envVals.length -1], textOriginX + 70, y);
-  g.drawString(anlgVals[anlgVals.length -1], textOriginX + 130, y);
+  g.drawString(rawBuf.getLastVal(), textOriginX + 0, y);
+  g.drawString(envBuf.getLastVal(), textOriginX + 70, y);
+  g.drawString(anlgBuf.getLastVal(), textOriginX + 130, y);
 
   y = y + 20;
   g.setFont("6x8", 2);
   g.drawString(slot0LedCurrentVal, textOriginX + 0, y);
   g.drawString(ledCurrentIdx, textOriginX + 70, y);
-  g.drawString((timeVals[timeVals.length-1]-timeVals[0])+"s", textOriginX + 130, y);
+  let t0 = timeBuf.getFirstVal()
+  let t1 = timeBuf.getLastVal();
+  g.drawString(Math.round(t1-t0)+"s", textOriginX + 130, y);
 
   //g.setFont("6x8", 2);
   //g.setFontAlign(-1, -1);
@@ -106,28 +172,28 @@ function drawText() {
   //g.setFont("6x8", 4);
   //g.drawString("^",screenSize/2 , 150);
 
-  drawGraph();
+  // commented out because drawGraph takes 2 seconds to run
+  //drawGraph();
   g.flip();
 }
 
 
 function drawGraph() {
   let i = 0;
   let y = 0;
+  let tStartg = getTime();
   //g.clear();
   g.clearRect(graphOriginX,graphOriginY,graphOriginX + graphW, graphOriginY + graphH);
 
   // Draw raw values as solid bars
-  let minVal = rawVals[0];
-  let maxVal = minVal;
-  for (i=0;i<rawVals.length; i++) {
-    if (rawVals[i]<minVal) minVal = rawVals[i];
-    if (rawVals[i]>maxVal) maxVal = rawVals[i];
-  }
+  let minMaxVals = rawBuf.getMaxMinVals();
+  let minVal = minMaxVals[0];
+  let maxVal = minMaxVals[1];
   let yMin = screenH;
   let yMax = graphOriginY;
-  for (i=0;i<rawVals.length-1; i++) {
-    y = yMin + (rawVals[i]-minVal)*(yMax-yMin)/(maxVal-minVal);
+  for (i=0;i<rawBuf.size -1; i++) {
+    var rawVal = rawBuf.getVal(i);
+    y = yMin + (rawVal-minVal)*(yMax-yMin)/(maxVal-minVal);
     if (y < yMax) y = yMax;   // Screen is inverted, so comparison looks wrong!
     if (y > yMin) y = yMin;
     g.setColor('#ff0000').drawRect(i,yMin,i+1,y);
@@ -139,6 +205,7 @@ function drawGraph() {
     +", y="+y);
 
     // Draw analogue values as a line
+    /*
     minVal = anlgVals[0];
     maxVal = minVal;
     for (i=0;i<anlgVals.length; i++) {
@@ -153,7 +220,9 @@ function drawGraph() {
       g.setColor('#000000').drawLine(lastPoint[0],lastPoint[1],i+1,y);
       lastPoint=[i, y];
     }
-
+   */
+  let tEndg = getTime();
+  console.log("drawGraph took "+(tEndg-tStartg).toFixed(3)+" sec");
 }
 
 function setLedCurrent() {
@@ -165,9 +234,17 @@ function setLedCurrent() {
 function getLedCurrent() {
   /**
    * Read the LED current registers from the HRM and populate the relevant global variables.
+   * We catch errors and re-start the HRM if we get an error, because occasional i2c errors
+   * during this call will freeze the HRM.
    */
-  slot0LedCurrentVal = Bangle.hrmRd(0x17,0);
-  ledCurentIdx = Bangle.hrmRd(0x19);
+  try {
+    slot0LedCurrentVal = Bangle.hrmRd(0x17,0);
+    ledCurentIdx = Bangle.hrmRd(0x19);
+  } catch (e) {
+    console.log("getLedCurrent - ERROR: "+e);
+    console.log("getLedCurrent - Re-Starting HRM");
+    initialiseHrm();
+  }
 }
 
 function changeLedCurrent(changeVal) {
@@ -200,12 +277,14 @@ function changeSlot0Current(changeVal) {
 
 function initialiseHrm() {
   Bangle.setLCDPower(1);
+  // Power cycle HRM
+  Bangle.setHRMPower(0);
   Bangle.setHRMPower(1);
   Bangle.setOptions({
     backlightTimeout:0,
     powerSave:false,
     hrmPushEnv:true,
-    hrmGreenAdjust: true
+    hrmGreenAdjust: false
   });
   setLedCurrent();
 
@@ -294,41 +373,37 @@ Bangle.on("swipe",function(directionLR, directionUD){
         changeLedCurrent(-1);
      }
     else if (directionUD ==1){
-      changeSlot0Current(5);
+      changeSlot0Current(1);
     }
     else if (directionUD == -1) {
-      changeSlot0Current(-5);
+      changeSlot0Current(-1);
     }
   });
 
 console.log("Registering raw hrm data callback");
 Bangle.on('HRM-raw', function (hrm) {
         let value = hrm.raw;
-        let filt = hrm.filt;
-        let valueA = Math.round(analogRead(29)* 16383);
-        rawVals.push(value); 
-        anlgVals.push(valueA);
-        timeVals.push(getTime());
-        if (rawVals.length > rawBufSize) {
-          rawVals.shift();
-          anlgVals.shift();
-          timeVals.shift();
-        }
-        file.write(timeVals[timeVals.length-1] + "," + value + "," + filt 
-                + "," + valueA + "," + envVals[envVals.length-1] + "," + HRVal + "," + HRConfidence + "\n");
+        let filt = 0;
+        //filt = hrm.filt;
+        valueA = Math.round(analogRead(29)* 16383);
+        rawBuf.setVal(value);
+        timeBuf.setVal(getTime());
+        console.log("HRM-raw - dt="+(timeBuf.getLastVal() - lastRawTime).toFixed(3)+" s: val="+value);
+        lastRawTime = timeBuf.getLastVal();
+        file.write(timeBuf.getLastVal() + "," + value + "," + filt 
+                + "," + valueA + "," + envBuf.getLastVal() + "," 
+                + HRVal + "," + HRConfidence + "\n");
 });
 
 console.log("Registering hrm environment data callback");
 Bangle.on('HRM-env', function (hrm) {
         let value = hrm;
-        envVals.push(value); 
-        if (envVals.length > rawBufSize) {
-          envVals.shift();
-        }
+        envBuf.setVal(value);
 });
 
 
 
+
 console.log("Registering hrm values callback");
 Bangle.on('HRM', function (hrmB) {
         HRVal = hrmB.bpm;

apps/hrmtest/arraytest.js

@@ -0,0 +1,11 @@
+vals = [];
+
+vals.push(1);
+vals.push(2);
+vals.push(3);
+
+console.log(vals);
+
+vals.shift(1);
+
+console.log(vals)

apps/hrmtest/circbuf.js

@@ -0,0 +1,88 @@
+class CircBuf {
+    constructor(bufSize) {
+      this.size = bufSize;
+      this.valArr = new Array(bufSize);
+      this.idx = 0;
+
+      this.getVal = function(n) { 
+      /**
+       * Return the value stored in position n in the buffer.
+       */
+
+        let i = n + this.idx;
+        if (i>=this.valArr.length)
+            i = i - this.valArr.length;
+        return(this.valArr[i]);
+      };
+
+      this.setVal = function(val) {
+        /**
+         * Add value val to the end of the buffer
+         */
+        this.valArr[this.idx] = val;
+        this.idx++;
+        if (this.idx == this.valArr.length)
+          this.idx = 0
+      };
+
+      this.getLastVal = function() {
+        /**
+         * get the last value added to the buffer
+         */
+        if (this.idx > 0)
+          return this.valArr[this.idx-1];
+        else
+          return this.valArr[this.valArr.length -1];
+      };
+
+      this.getFirstVal = function() {
+        /**
+         * get the first value in the buffer
+         */
+        // FIXME - this is only correct once the buffer is full
+        return this.valArr[this.idx];
+      };
+
+      this.getMaxMinVals = function() {
+        /**
+         * return [minVal, maxVal] for the buffer.
+         */
+        let i = 0;
+        let minVal = this.valArr[0];
+        let maxVal = this.valArr[0];
+        for (i=0;i<this.size;i++) {
+          if (this.valArr[i]<minVal)
+            minVal = this.valArr[i];
+          if (this.valArr[i]>maxVal)
+            maxVal = this.valArr[i];
+        }
+        return [minVal, maxVal];
+      }
+    }
+  }
+
+  function runTests() {
+    console.log("CircBuf.runTests()");
+    let buf = new CircBuf(5);
+    buf.setVal(1);
+    buf.setVal(2);
+    buf.setVal(3);
+    buf.setVal(4);
+    buf.setVal(5);
+    buf.setVal(6);
+    console.log(buf);
+
+    console.log("first="+buf.getFirstVal()+", last="+buf.getLastVal());
+    for (let i=0;i<5;i++) {
+        console.log("buf("+i+") = "+buf.getVal(i));
+    }
+
+    buf.setVal(7);
+    buf.setVal(8);
+    console.log("first="+buf.getFirstVal()+", last="+buf.getLastVal());
+    for (let i=0;i<5;i++) {
+        console.log("buf("+i+") = "+buf.getVal(i));
+    }
+    }
+
+  runTests();