Recorder: Use average of HR readings

apps/recorder/ChangeLog

@@ -61,4 +61,6 @@
 0.47: Fix 'blip' on speed map on some recordings
       Ensure Battery voltage is only stored to 0.01v
       Add graphs for Steps+Battery
-0.48: Add ability to log average acceleration values
+0.48: Add ability to log average acceleration values
+0.49: Log average high confidence (>=80) HR reading for each interval, instead of logging the last 
+      reading. If none pass confidence threshold, fall back to highest low confidence reading.

apps/recorder/lib.js

@@ -61,18 +61,45 @@ exports.getRecorders = function() {
       };
     },
     hrm:function() {
-      var bpm = "", bpmConfidence = "", src="";
+      const CONFIDENCE_THRESHOLD = 80;
+      var avgBpm = 0, avgBpmConfidence = 0, src="", nAvgReadings=0, lowConfBpm=null, lowConfBpmConfidence=-1;
+
       function onHRM(h) {
-        bpmConfidence = h.confidence;
-        bpm = h.bpm;
+        let newBpmConfidence = h.confidence;
+        let newBpm = h.bpm;
         src = h.src;
+
+        if (newBpmConfidence >= CONFIDENCE_THRESHOLD){
+          nAvgReadings++;
+          avgBpm = avgBpm + (newBpm-avgBpm)/nAvgReadings;
+          avgBpmConfidence = avgBpmConfidence + (newBpmConfidence-avgBpmConfidence)/nAvgReadings;
+
+        } else if (newBpmConfidence > lowConfBpmConfidence) {
+          lowConfBpmConfidence = newBpmConfidence;
+          lowConfBpm = newBpm;
+        }
       }
+
       return {
         name : "HR",
         fields : ["Heartrate", "Confidence", "Source"],
         getValues : () => {
-          var r = [bpm,bpmConfidence,src];
-          bpm = ""; bpmConfidence = ""; src="";
+          let r;
+
+          if (nAvgReadings === 0) {
+            if (lowConfBpm === null) r = ["","",""];
+            else r = [lowConfBpm,lowConfBpmConfidence,src];
+          } else {
+            r = [Math.round(avgBpm),Math.round(avgBpmConfidence),src];
+          }
+
+          avgBpm = 0; 
+          avgBpmConfidence = 0; 
+          nAvgReadings=0; 
+          lowConfBpm=null; 
+          lowConfBpmConfidence=-1;
+          src=""; 
+
           return r;
         },
         start : () => {
@@ -384,4 +411,4 @@ exports.isRecording = function() {
   return !!writeSetup;
 };
 
-exports.reload({noUpdateWidget:true});
+exports.reload({noUpdateWidget:true});

apps/recorder/metadata.json

@@ -2,7 +2,7 @@
   "id": "recorder",
   "name": "Recorder",
   "shortName": "Recorder",
-  "version": "0.48",
+  "version": "0.49",
   "author": "bobrippling",
   "description": "Record GPS position, heart rate and more in the background, then download to your PC.",
   "icon": "app.png",