add timeout in case Noble doesn't power on, fix #25

Author: gfwilliams

lib/discovery.js

@@ -30,8 +30,21 @@ function log(x) {
 }
 
 // ----------------------------------------------------------------------
+var powerOnTimer;
+if (config.ble_timeout > 0)
+  powerOnTimer = setTimeout(function() {
+    powerOnTimer = undefined;
+    log("BLE broken? No Noble State Change to 'poweredOn' in "+ config.ble_timeout +" seconds - restarting!");
+    process.exit(1);
+  }, config.ble_timeout * 1000)
+
 function onStateChange(state) {
+  log("Noble StateChange: "+state);
   if (state!="poweredOn") return;
+  if (powerOnTimer) {
+    clearTimeout(powerOnTimer);
+    powerOnTimer = undefined;
+  }
   // delay startup to allow Bleno to set discovery up
   setTimeout(function() {
     log("Starting scan...");
@@ -187,7 +200,10 @@ exports.inRange = inRange;
 
 exports.restartScan = function() {
   if (!isScanning) {
+    log("Restarting scan");
     noble.startScanning([], true);
+  } else {
+    log("restartScan: already scanning!");
   }
 }