add connection watchdog

assets/js/sumorobot.js

@@ -24,6 +24,8 @@ var codingEnabled = false;
 /* disable / enable live stream */
 var liveStreamVisible = false;
 
+/* connection watchdog */
+var watchdogCounter = 0;
 /* control_if block id */
 var controlBlockId = "";
 /* last hightlighted block id */
@@ -44,6 +46,15 @@ Sumorobot.prototype.connect = function() {
     /* to have access to this object */
     var self = this;
     this.websocket = new WebSocket(this.wsUri);
+    /* setup connection watchdog */
+    setInterval(function() {
+        if (watchdogCounter == 0) {
+            $("#battery").removeClass("connected");
+            $("#battery").html("Disconnected");
+        }
+        /* reset watchdog counter */
+        watchdogCounter = 0;
+    }, 3000);
     /* when the WebSocket gets connected */
     this.websocket.onopen = function(evt) {
         console.log("INFO websocket connected");
@@ -70,6 +81,9 @@ Sumorobot.prototype.connect = function() {
         var battery = JSON.parse(data)["battery_voltage"];
         $("#battery").html(battery + "V");
         $("#battery").addClass("connected");
+        /* keep track of data packets */
+        /* to see if we have a connection to the robot */
+        watchdogCounter += 1;
     };
     /* when there is an WebSocket error */
     this.websocket.onerror = function(err) {