diff --git a/speed.trailsense.js b/speed.trailsense.js
index 40367d7..042b6bd 100644
--- a/speed.trailsense.js
+++ b/speed.trailsense.js
@@ -1,6 +1,5 @@
 (() => {
 let STOR = require("Storage");
-let updateInterval;
 let lastSpeed;
 
 function drawFace() {
@@ -46,52 +45,50 @@ function drawFace() {
   }
 
 
-  updateInterval = setInterval(
-  () => {
-    var gps_fix = Bangle.getGPSFix();
-    var speed = round(gps_fix.speed, 1);
-    if(speed<3.4) speed="0.0";
-    if(Number(speed)>maxSpeed) maxSpeed = speed;
-    if(maxSpeed > maxSpeedEver) { STOR.write("maxspeed.trailsense.json", maxSpeed.toString()); }
-    maxSpeedEver = Number(STOR.read("maxspeed.trailsense.json")) || 0;
+  Bangle.on("GPS", 
+    (gps_fix) => {
+      var speed = round(gps_fix.speed, 1);
+      if(speed<3.4) speed="0.0";
+      if(Number(speed)>maxSpeed) maxSpeed = speed;
+      if(maxSpeed > maxSpeedEver) { STOR.write("maxspeed.trailsense.json", maxSpeed.toString()); }
+      maxSpeedEver = Number(STOR.read("maxspeed.trailsense.json")) || 0;
 
-    if((speed != lastSpeed || first_run) && !isNaN(speed)) {
-      first_run = false;
-      naNShown = false;  // update naNShown for accidently signal loss (so that the loop down there can run again)
+      if((speed != lastSpeed || first_run) && !isNaN(speed)) {
+        first_run = false;
+        naNShown = false;  // update naNShown for accidently signal loss (so that the loop down there can run again)
 
-      // clear screen
-      g.setColor(g.theme.bg);
-      g.fillRect(0, g.getHeight()/2-30, g.getWidth(), g.getHeight()/2+30);
+        // clear screen
+        g.setColor(g.theme.bg);
+        g.fillRect(0, g.getHeight()/2-30, g.getWidth(), g.getHeight()/2+30);
 
-      // draw speed
-      g.setColor(g.theme.fg);
-      g.setFont(speedFont, speedSize);
-      g.drawString(speed, g.getWidth()/2, g.getHeight()/2);
+        // draw speed
+        g.setColor(g.theme.fg);
+        g.setFont(speedFont, speedSize);
+        g.drawString(speed, g.getWidth()/2, g.getHeight()/2);
 
-      // draw speed highscore
-      g.setColor(g.theme.bg);
-      g.fillRect(0, g.getHeight()-maxSpeedSize*2, g.getWidth(), g.getHeight()-maxSpeedSize/2)
-      g.setColor(g.theme.fg);
-      g.setFont(maxSpeedFont, maxSpeedSize);
-      g.drawString(round(maxSpeed, 1) + " / " + maxSpeedEver, g.getWidth()/2, g.getHeight()-maxSpeedSize);
-    } else if(isNaN(speed) && !naNShown) {
-      g.setColor(g.theme.bg);
-      g.fillRect(0, g.getHeight()/2-30, g.getWidth(), g.getHeight()/2+30);
-      g.setColor(g.theme.fg);
-      g.setFont(speedFont, speedNaNSize);
-      g.drawString("Loading...", g.getWidth()/2, g.getHeight()/2);
+        // draw speed highscore
+        g.setColor(g.theme.bg);
+        g.fillRect(0, g.getHeight()-maxSpeedSize*2, g.getWidth(), g.getHeight()-maxSpeedSize/2)
+        g.setColor(g.theme.fg);
+        g.setFont(maxSpeedFont, maxSpeedSize);
+        g.drawString(round(maxSpeed, 1) + " / " + maxSpeedEver, g.getWidth()/2, g.getHeight()-maxSpeedSize);
+      } else if(isNaN(speed) && !naNShown) {
+        g.setColor(g.theme.bg);
+        g.fillRect(0, g.getHeight()/2-30, g.getWidth(), g.getHeight()/2+30);
+        g.setColor(g.theme.fg);
+        g.setFont(speedFont, speedNaNSize);
+        g.drawString("Loading...", g.getWidth()/2, g.getHeight()/2);
 
-      naNShown = true;
-    }
-    lastSpeed = speed;  // set last speed var for next loop
-  }, 100)
+        naNShown = true;
+      }
+      lastSpeed = speed;  // set last speed var for next loop
+  })
 }
 
 function stop() {
   g.clear();
+  Bangle.removeAllListeners();
   Bangle.setGPSPower(false);
-  print("[DEBUG] updateInterval=" + updateInterval);
-  clearInterval(updateInterval);
 }
 
 return { drawFace:drawFace, stop:stop };