diff --git a/apps/cscsensor/README.md b/apps/cscsensor/README.md
index b353c430e..185aebc12 100644
--- a/apps/cscsensor/README.md
+++ b/apps/cscsensor/README.md
@@ -1,3 +1,15 @@
 # CSCSensor
 
-TBD
+Simple app that can read a cycling speed and cadence (CSC) sensor and display the information on the watch.
+Currently the app displays the following data:
+
+- moving time
+- current speed
+- average speed
+- maximum speed
+- distance traveled
+
+Button 1 resets all measurements.
+
+I do not have acces to a cadence sensor at the moment, so only the speed part is currently implemented. Values displayed are imperial, and a wheel diameter
+of 28 inches is assumed. A settings dialog to configure units and wheel sizes will (hopefully) be added later.
diff --git a/apps/cscsensor/cscsensor.app.js b/apps/cscsensor/cscsensor.app.js
index 88abd43ff..1a250bda0 100644
--- a/apps/cscsensor/cscsensor.app.js
+++ b/apps/cscsensor/cscsensor.app.js
@@ -16,17 +16,23 @@ class CSCSensor {
     this.maxSpeed = 0;
     this.lastSpeed = 0;
     this.qUpdateScreen = true;
+    this.lastRevsStart = -1;
+  }
+  reset() {
+    this.maxSpeed = 0;
+    this.movingTime = 0;
+    this.lastRevsStart = this.lastRevs;
+    this.maxSpeed = 0;
   }
-
   updateScreen() {
-    var dist = this.lastRevs*this.wheelDia*Math.PI/63360.0;
+    var dist = (this.lastRevs-this.lastRevsStart)*this.wheelDia*Math.PI/63360.0;
     var ddist = Math.round(100*dist)/100;
     var dspeed = Math.round(10*this.speed)/10; 
     var dmins = Math.floor(this.movingTime/60).toString();
     if (dmins.length<2) dmins = "0"+dmins;
     var dsecs = (Math.floor(this.movingTime) % 60).toString();
     if (dsecs.length<2) dsecs = "0"+dsecs;
-    var avespeed = Math.round(10*dist/this.movingTime)/10;
+    var avespeed = (this.movingTime>0 ? Math.round(10*dist/(this.movingTime/3600))/10 : 0);
     var maxspeed = Math.round(10*this.maxSpeed)/10;
     g.setFontAlign(1, -1, 0).setFontVector(18).setColor(1, 1, 0);
     g.drawString("Time:", 86, 60);
@@ -41,7 +47,6 @@ class CSCSensor {
     g.drawString(maxspeed + " mph", 92, 160);
     g.drawString(ddist + " miles", 92, 192);    
   }
-
   updateSensor(event) {
     var qChanged = false;
     if (event.target.uuid == "0x2a5b") {
@@ -49,6 +54,7 @@ class CSCSensor {
       var dRevs = (this.lastRevs>0 ? wheelRevs-this.lastRevs : 0);
       if (dRevs>0) qChanged = true;
       this.lastRevs = wheelRevs;
+      if (this.lastRevsStart<0) this.lastRevsStart = wheelRevs;
       var wheelTime = event.target.value.getUint16(5, true);
       var dT = (wheelTime-this.lastTime)/1024;
       var dBT = (Date.now()-this.lastBangleTime)/1000;
@@ -103,7 +109,9 @@ NRF.setScan(parseDevice, { filters: [{services:["1816"]}], timeout: 2000});
 g.clearRect(0, 60, 239, 239).setFontVector(18).setFontAlign(0, 0, 0).setColor(0, 1, 0);
 g.drawString("Scanning for CSC sensor...", 120, 120);
 
+setWatch(function() { mySensor.reset(); mySensor.updateScreen(); }, BTN1);
+
 Bangle.on('kill',()=>{ if (gatt!=undefined) gatt.disconnect()});
 
 Bangle.loadWidgets();
-Bangle.drawWidgets();
\ No newline at end of file
+Bangle.drawWidgets();