Add heart rate widget

apps.json

@@ -319,6 +319,17 @@
       {"name":"*hrm","url":"heartrate-icon.js","evaluate":true}
     ]
   },
+  { "id": "whrm",
+    "name": "Simple Heart Rate widget",
+    "icon": "widget.png",
+    "version":"0.01",
+    "description": "When the screen is turned on, the widget turns on the heart rate monitor and displays the detected heart rate - can take 20s to get a reading.",
+    "tags": "health,widget",
+    "storage": [
+      {"name":"+whrm","url":"widget.json"},
+      {"name":"=whrm","url":"widget.js"}
+    ]
+  },
   { "id": "stetho",
     "name": "Stethoscope",
     "icon": "stetho.png",

apps/whrm/ChangeLog

@@ -0,0 +1 @@
+0.01: New Widget!

apps/whrm/widget.js

@@ -0,0 +1,53 @@
+(() => {
+  var xpos = WIDGETPOS.tl;
+  var width = 24;
+  WIDGETPOS.tl += width+2;
+  var currentBPM = undefined;
+  var lastBPM = undefined;
+  var firstBPM = true; // first reading since sensor turned on
+
+  function draw() {
+  	g.reset();
+    g.setFont("6x8", 1);
+    g.setFontAlign(0, 0);
+    g.clearRect(xpos,15,xpos+width,24); // erase background
+    var bpm = currentBPM, isCurrent = true;
+    if (bpm===undefined) {
+      bpm = lastBPM;
+      isCurrent = false;
+    }
+    if (bpm===undefined)
+      bpm = "--";
+    g.setColor(isCurrent ? "#ffffff" : "#808080");
+    g.drawString(bpm, xpos+width/2, 19);
+    g.setColor(isCurrent ? "#ff0033" : "#808080");
+    g.drawImage(atob("CgoCAAABpaQ//9v//r//5//9L//A/+AC+AAFAA=="),xpos+(width-10)/2,1);
+    g.setColor(-1);
+  }
+
+  // redraw when the LCD turns on
+  Bangle.on('lcdPower', function(on) {
+    if (on) {
+      Bangle.setHRMPower(1);
+      firstBPM = true;
+      currentBPM = undefined;
+      draw();
+    } else {
+      Bangle.setHRMPower(0);
+    }
+  });
+
+  Bangle.on('HRM',function(d) {
+    if (firstBPM)
+      firstBPM=false; // ignore the first one as it's usually rubbish
+    else {
+      currentBPM = d.bpm;
+      lastBPM = currentBPM;
+    }
+    draw();
+  });
+  Bangle.setHRMPower(Bangle.isLCDOn());
+
+  // add your widget
+  WIDGETS["hrm"]={draw:draw};
+})();

apps/whrm/widget.json

@@ -0,0 +1,4 @@
+{
+  "name":"Heart Rate Widget", "type":"widget",
+  "src":"=whrm"
+}