Feature/enhance connection to multiple ble devices

lib/adaptors/ble.js

@@ -85,8 +85,12 @@ Adaptor.prototype.open = function open(callback) {
     // connect to peripheral using noble
     ble.on("discover", function(peripheral) {
       if (peripheral.id === self.uuid) {
+
         ble.stopScanning();
-        self._connectPeripheral(peripheral, callback);
+        self._connectPeripheral(peripheral, function() {
+          ble.startScanning();
+          callback();
+        });
       }
     });