ble-ble113a/index.js

// Copyright 2014 Technical Machine, Inc. See the COPYRIGHT
// file at the top-level directory of this distribution.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

var Peripheral = require('./lib/peripheral');
var Descriptor = require('./lib/descriptor');
var Characteristic = require('./lib/characteristic');
var Service = require('./lib/service');
var Messenger = require('./lib/messenger');
var UUID = require('./lib/uuid');
var Address = require('./lib/address');
var attributes = require('./lib/attributes.json');
var profile = require('./lib/profile.json');
var events = require('events');
var util = require('util');
var async = require('async');

// Instantiate a Bluetooth Controller object. Controls all BLE Central and Peripheral methods (depending on role).
function BluetoothController(hardware, callback) {
  this.hardware = hardware;
  this.isAdvertising = false;
  this.messenger = new Messenger(hardware);
  this._connectedPeripherals = {};

  this.profile = profile;

  this._firmwareVersionHandle = 17;
  this._maxNumValues = { "1.0.1" : 12};
  this._localHandles = [21, 25, 29, 33, 37, 41, 45, 49, 53, 57, 61, 65];

  this._MITMEnabled = false;
  this._minKeySize = 7;

  this._userAdvData = true;

  this.messenger.on('scanStart', this.onScanStart.bind(this));
  this.messenger.on('scanStop', this.onScanStop.bind(this));
  this.messenger.on('discover', this.onDiscover.bind(this));
  this.messenger.on('connectionStatus', this.onConnectionStatus.bind(this));
  this.messenger.on('disconnect', this.onDisconnect.bind(this));
  this.messenger.on('groupFound', this.onGroupFound.bind(this));
  this.messenger.on('completedProcedure', this.onCompletedProcedure.bind(this));
  this.messenger.on('findInformationFound', this.onFindInformationFound.bind(this));
  this.messenger.on('attributeValue', this.onAttributeValue.bind(this));
  this.messenger.on('remoteWrite', this.onRemoteWrite.bind(this));
  this.messenger.on('remoteStatus', this.onRemoteStatus.bind(this));
  this.messenger.on('portStatus', this.onPortStatus.bind(this));
  this.messenger.on('ADCRead', this.onADCRead.bind(this));
  this.messenger.on('bondStatus', this.onBondStatus.bind(this));
  this.messenger.on('indicated', this.onIndicated.bind(this));

  // Once the messenger says we're ready, call callback and emit event
  this.messenger.once('ready', this.bootSequence.bind(this, callback));

  // If there was an error, let us know
  this.messenger.once('error', this.bootSequence.bind(this, callback));
}

util.inherits(BluetoothController, events.EventEmitter);

BluetoothController.prototype.bootSequence = function(callback, err) {

// Tell any ble listeners
  if (!err) {
    this.createGPIOs();
    // Set default adevertising data
    // LE General Discoverable / BR/EDR not supported
    // Short device name: Tessel
    this.setAdvertisingData([0x02, 0x01, 0x06, 0x07, 0x08, 0x54, 0x65, 0x73, 0x73, 0x65, 0x6c], function(){
      setImmediate(function() {
        this.emit('ready');
        // Call the callback
        if (callback) {
          callback(null, this);
        }
      }.bind(this));
    }.bind(this));
  } else {
    // Emit the error
    setImmediate(function() {
      this.emit('error', err);
      // Call the callback
      if (callback) {
        callback(err, this);
      }
    }.bind(this));
  }

  this.messenger.removeAllListeners('error');
  this.messenger.removeAllListeners('ready');
};

BluetoothController.prototype.reset = function(callback) {
  this.messenger.reset(callback);
};
/**********************************************************
 Event Handlers
**********************************************************/
BluetoothController.prototype.onScanStart = function(err, result) {
  this.emit('scanStart', err);
};

BluetoothController.prototype.onScanStop = function(err, result) {
  this.emit('scanStop', err);
};

BluetoothController.prototype.onDiscover = function(peripheralData) {
  // Try to grab this peripheral from list of previously discovered peripherals
  this.getPeripheralFromData(peripheralData.rssi, peripheralData.data, peripheralData.sender, peripheralData.address_type, function(peripheral, undiscovered) {
    // If we are not filtering UUIDs or we are and this is a match
    if (!this.filteredUUIDs.length || this.matchAdvDataUUID(peripheralData.data)) {
      // Emit the event
      setImmediate(function() {
        this.emit('discover', peripheral);
      }.bind(this));
    }
  }.bind(this));
};

BluetoothController.prototype.matchAdvDataUUID = function(data) {
  for (var i in data) {
    var datum = data[i];

    // For each piece of advertising data
    if (datum.typeFlag >= 2 && datum.typeFlag <= 7) {
      // For each uuid in each datum
      for (var j in datum.data) {
        // Grab the uuid
        var uuid = datum.data[j];
        // For each filter uuid
        for (var k in this.filteredUUIDs) {
          // Grab the filter
          var filter = this.filteredUUIDs[k];
          // If it's a match
          if (filter === uuid) {
            // return true
            return true;
          }
        }

      }
    }
  }

  // No matches found
  return false;
};

BluetoothController.prototype.onConnectionStatus = function(status) {
  // If we're advertising in slave mode
  if (this.advertising) {
    // Emit that we connected with the connection number
    setImmediate(function() {
      this.emit('connect', status.connection);
    }.bind(this));
  } else {
    // If we're in master mode
    // Grab the peripheral
    this.getPeripheralFromData(null, null, status.address, status.address_type, function(peripheral, undiscovered) {

      if (peripheral) {
        // Set the connection number and flags
        peripheral.connection = status.connection;
        peripheral.flags = status.flags;
        peripheral.bondHandle = status.bonding;

        // Save it in our data structure
        this._connectedPeripherals[peripheral.connection] = peripheral;

        // If this new connection was just made
        // Let any listeners know
        if (peripheral.flags & (1 << 2)) {
          peripheral.connected = true;
          setImmediate(function() {
            this.emit('connect', peripheral);
          }.bind(this));
        }
      }
    }.bind(this));
  }
  this.emit('connectionStatus', status);
};

BluetoothController.prototype.onDisconnect = function(response) {

  var peripheral = this._connectedPeripherals[response.connection];

  // If we have a peripheral (we're acting as master)
  if (peripheral) {
    // Set the flags
    peripheral.flags = 0;
    peripheral.connection = null;
    peripheral.connected = false;

    // Emit the event
    setImmediate(function() {
      this.emit('disconnect', peripheral, response.reason);
    }.bind(this));
  } else {
    // If we're acting as slave
    // Emit event with connection param
    setImmediate(function() {
      this.emit('disconnect', response.connection, response.reason);
    }.bind(this));
  }
};

/*
 Called when services or groups found
*/
BluetoothController.prototype.onGroupFound = function(group) {
  this.emit('groupFound', group);
};
/*
 Called when discovery operation completed
*/
BluetoothController.prototype.onCompletedProcedure = function(procedure) {
  this.emit('completedProcedure', procedure);
};

/*
 Called when characteristic discovery is complete
 */
BluetoothController.prototype.onFindInformationFound = function(info) {
  this.emit('findInformationFound', info);
};

/*
 Called when an attribute value is found
 */
BluetoothController.prototype.onAttributeValue = function(value) {
  // We have a notification
  if (value.type === 1) {
    // Grab the peripheral responsible
    var peripheral = this._connectedPeripherals[value.connection];
    // If it exists (it better!)
    if (peripheral) {
      // Grab the corresponding characteristic
      var characteristic = peripheral.characteristics[value.atthandle];
      // If it exists (it better!)
      if (characteristic) {
        // Set the value
        characteristic.value = value.value;

        // Emit events
        this.emit('notification', characteristic, characteristic.value);
        peripheral.emit('notification', characteristic, characteristic.value);
        characteristic.emit('notification', characteristic.value);
      }
    }
  } else if (value.type === 2 || value.type === 5) {
    // We have an indication
    // Grab the peripheral responsible
    var peripheral = this._connectedPeripherals[value.connection];
    // If it exists (it better!)
    if (peripheral) {
      // Grab the corresponding characteristic
      var characteristic = peripheral.characteristics[value.atthandle];
      // If it exists (it better!)
      if (characteristic) {
        // Set the value
        characteristic.value = value.value;

        // Emit events
        this.emit('indication', characteristic, characteristic.value);
        peripheral.emit('indication', characteristic, characteristic.value);
        characteristic.emit('indication', characteristic.value);
      }
    }
  }

  this.emit('attributeValue', value);
};

BluetoothController.prototype.onRemoteWrite = function(value) {
  // If the master is requesting confirmation
  if (value.reason === 2) {
    this.messenger.remoteWriteAck(value.connection, 0x00, function(err, response) {
        // TODO: Do we need anything with this response?
    });
  }
  var index = this._localHandles.indexOf(value.handle);
  if (index != -1) {
    setImmediate(function() {
      this.emit('remoteWrite', value.connection, index, value.value);
    }.bind(this));
  }
};

BluetoothController.prototype.onRemoteStatus = function(status) {
  var index = this._localHandles.indexOf(status.handle);
  if (index != -1) {
    var action;
    if (status.flags === 0) {
      action = "remoteUpdateStop";
    }
    if (status.flags === 1) {
      action = "remoteNotification";
    } else if (status.flags === 2) {
      action = "remoteIndication";
    }

    setImmediate(function() {
      this.emit(action, status.connection, index);
    }.bind(this));
  }
};

BluetoothController.prototype.onPortStatus = function(portStatus) {
  // Iterate through gpios
  for (var id in this.gpios) {
    var gpio = this.gpios[id];
    // If it's the right port and pin
    if (gpio._port == portStatus.port && (portStatus.irq & (1 << gpio._pin))) {
      // Set the correct type of interrupt
      var type = (portStatus.state & (1 << gpio._pin)) ? "rise" : "fall";
      // Emit that type as well as the change type
      setImmediate(function() {
        gpio.emit("change", null, portStatus.timestamp, type);
        gpio.emit(type, null, portStatus.timestamp, type);
      });
    }
  }
};

BluetoothController.prototype.onADCRead = function(adcRead) {
  this.emit('ADCRead', adcRead);
};

BluetoothController.prototype.onBondStatus = function(bondStatus) {
  this.emit('bondStatus', bondStatus);
};

BluetoothController.prototype.onIndicated = function(indicated) {
  var index = this._localHandles.indexOf(indicated.attrhandle);
  if (index != -1) {
    this.emit('indicated', indicated.connection, index);
  }
};

/**********************************************************
 Bluetooth API
**********************************************************/
BluetoothController.prototype.startScanning = function(options, callback) {

  // If the user just passed in a function, make allow duplicates a null
  if (typeof options == "function" || (!options && !callback)) {
    callback = options;
    options = {};
  }

  this._allowDuplicates = (options.allowDuplicates ? true : false);

  this.filteredUUIDs = (options.serviceUUIDs ? options.serviceUUIDs : []);

  // Reset discovered peripherals
  this._discoveredPeripherals = {};

  // Set scan filtering parameters
  // Accept all advertisments, respond to all masters
  this.messenger.setFiltering(0, 0, !this._allowDuplicates, function(err, response){
    if (err) {
      callback && callback(err)
    } else {
      // Start scanning
      this.messenger.startScanning(this.manageRequestResult.bind(this, 'scanStart', callback));
    }
  }.bind(this));

};

BluetoothController.prototype.stopScanning = function(callback) {
  this.messenger.stopScanning(this.manageRequestResult.bind(this, 'scanStop', callback));
};

BluetoothController.prototype.manageRequestResult = function(event, callback, err, response) {
  // If there wasn't an error
  if (!err) {
    // Emit the event
    setImmediate(function() {
      this.emit(event);
    }.bind(this));
  } else {
    setImmediate(function() {
      this.emit('error', err);
    }.bind(this));
  }

  // Call the callback
  if (callback) {
    callback(err);
  }
};

BluetoothController.prototype.getPeripheralFromData = function(rssi, data, address, addressType, callback) {

  var addr = new Address(address);
  // Make a peripheral object from the data
  peripheral = new Peripheral(
              this,
              rssi,
              data,
              addr);

  peripheral.addressType = addressType;

  if (callback) {
    callback(peripheral, true);
  }
};

BluetoothController.prototype.connect = function(peripheral, callback) {
  this.messenger.connect(peripheral.address.toBuffer(), peripheral.addressType, function(err, response) {
    function connectCallback(connectedPeripheral) {
      if (peripheral === connectedPeripheral) {
        // Remove this listener
        self.removeListener('connect', connectCallback);
        // Call the callback
        if (callback) {
          callback();
        }
        setImmediate(function() {
          // Let any listeners know
          peripheral.emit('connect');
        });
      }
    }
    // If there was an error
    if (err) {
      // Call the callback
      if (callback) {
        callback(err);
      }
      return;
    } else {
      var self = this;
      // Wait for a connection Update
      this.on('connect', connectCallback);
    }
  }.bind(this));
};

BluetoothController.prototype.disconnect = function(peripheral, callback) {
  this.messenger.disconnect(peripheral.connection, function(err, response) {
    // If there was an error
    if (err) {
      // Call the callback
      if (callback) {
        callback(err);
      }
      return;
    } else {
      // Wait for a connection Update
      this.on('disconnect', function disconnectCallback(disconnectedPeripheral) {
        if (disconnectedPeripheral === peripheral) {

          // Remove this listener
          this.removeListener('disconnect', disconnectCallback);

          // Call the callback
          if (callback) {
            callback(reason);
          }

          setImmediate(function() {
            // Let any listeners know
            peripheral.emit('disconnect', reason);
          }.bind(this));
        }
      }.bind(this));
    }
  }.bind(this));
};

BluetoothController.prototype.discoverAllAttributes = function(peripheral, callback) {
  // Discover all of our services and characteristics
  this.discoverAllServicesAndCharacteristics(peripheral, function(err, results) {
    var funcs = [];
    for (var characteristic in results.characteristics) {
      funcs.push(this.discoverDescriptorsOfCharacteristic.bind(this, results.characteristics[characteristic]));
    }
    // Get an array of arrays of descriptors
    async.series(funcs, function(err, charDescriptors) {
      // Make return array
      var allDescriptors = [];
      // For each array of descriptors
      for (var i in charDescriptors) {
        // For each descriptor in that array
        for (var descriptor in charDescriptors[i]) {
          // Push the descriptor
          allDescriptors.push(charDescriptors[i][descriptor]);
        }
      }

      // Add descriptors to the resulting object
      results.descriptors = allDescriptors;

      // Call the callback
      if (callback) {
        callback(err, results);
      }
    });
  }.bind(this));
};

BluetoothController.prototype.discoverAllServices = function(peripheral, callback)
{
  this.discoverServices(peripheral, [], callback);
};

BluetoothController.prototype.discoverServices = function(peripheral, filter, callback)
{
  // Discover the services of this device
  this.serviceDiscovery(peripheral, false, function(err, allServices) {
    if (err) {
      if (callback) {
        callback(err);
      }
      return;
    } else {
      this.attributeDiscoveryHandler(err, filter, allServices, function(err, services) {

        // Return the values
        if (callback) {
          callback(err, services);
        }

        if (!err && services.length) {
          // Set the events to be emitted.
          setImmediate(function() {
            this.emit('servicesDiscover', services);
            peripheral.emit('servicesDiscover', services);
          }.bind(this));
        }
      }.bind(this));
    }
  }.bind(this));
};

// TODO: Implement this function
BluetoothController.prototype.discoverIncludedServices = function(peripheral, callback) {
  this.serviceDiscovery(peripheral, true, function(err, services) {
    if (err) {
      if (callback) {
        callback(err);
      }
      return;
    } else {
      // TODO what goes here?
    }
  });
};

BluetoothController.prototype.serviceDiscovery = function(peripheral, included, callback) {

  var services = [];

  // The 'groupFound' event is called when we find a service
  var groupFoundListener = this.createServiceFromGroup.bind(this, peripheral, services);

  this.on('groupFound', groupFoundListener);

  var self = this;
  // The 'completed Procedure' event is called when we're done looking for services
  this.on('completedProcedure', function serviceDiscoveryComplete(procedure) {
    // If this was called for this peripheral
    if (procedure.connection === peripheral.connection) {

      // Remove the listener
      self.removeListener('groupFound', groupFoundListener);
      self.removeListener('completedProcedure', serviceDiscoveryComplete);

      // Call the callback
      if (callback) {
        callback(null, services);
      }
    }
  });

  var discoveryProcedure;

  if (included) {
    // Request the messenger to start discovering services
    this.messenger.discoverIncludedServices(peripheral, function(err, response) {
      // If there was a problem with the request
      if (err) {
        // Call callback immediately
        return callback && callback(err);
      }
    });
  } else {
    // Request the messenger to start discovering services
    this.messenger.discoverServices(peripheral, function(err, response) {
      // If there was a problem with the request
      if (err) {
        // Call callback immediately
        return callback && callback(err);
      }
    });
  }
};

BluetoothController.prototype.attributeDiscoveryHandler = function(err, filter, attributes, callback) {
  // If there was an error, report it
  if (err) {
    if (callback) {
      callback(err);
    }

    setImmediate(function() {
      this.emit('error', err);
    }.bind(this));

    return;
  } else {
    // Create a return array
    var ret = [];
          // If consumer has requested a subset of services
    if (filter.length != 0) {
      // Iterate through the services requested
      for (var i = 0; i < filter.length; i++) {
        // Convert filter to lower case
        var match = filter[i].toLowerCase();
        // If the service details exist and was returned
        for (var j = 0; j < attributes.length; j++) {
          // If the attribute's uuid is the filter
          if (attributes[j].uuid.toString() == match) {
            // Add it to the array
            ret.push(attributes[j]);
            break;
          }
        }
      }
    } else {
      // If the consumer has requested all services
      ret = attributes;
    }

    // Return the values
    if (callback) {
      callback(null, ret);
    }
  }
};

BluetoothController.prototype.createServiceFromGroup = function(peripheral, ret, groupItem) {
  // If this is the right peripheral
  if (groupItem.connection === peripheral.connection) {
    // Convert the UUID to a string instead of buffer
    var uuid = new UUID(groupItem.uuid);

    var service;

    // If the service doesn't already exist
    if (!(service = peripheral[uuid.toString()])) {
      // Make a new service
      service = new Service(peripheral, uuid, groupItem.start, groupItem.end);
      // Add this services to the peripherals data structure
      peripheral.syncService(service);
    }

    // Add to the service we will report as having discovered
    ret.push(service);
  }
};

BluetoothController.prototype.discoverAllCharacteristics = function(peripheral, callback) {

  this.discoverAllServices(peripheral, function(err, services) {
    if (err) {
      if(callback) {
        callback(err);
      }
    } else {
      var characteristics = [];

      var self = this;

      var discoveryListener = this.createCharacteristicFromInformationFound.bind(this, peripheral, characteristics);

      this.on('findInformationFound', discoveryListener);

      this.on('completedProcedure', function charDiscoveryComplete(procedure) {
        if (procedure.connection === peripheral.connection) {

          self.removeListener('findInformationFound', discoveryListener);
          self.removeListener('completedProcedure', charDiscoveryComplete);

          // If it didn't succeed
          if (procedure.result != 0) {
            if (callback) {
              callback(procedure.result, null);
            }
          } else {
            if (callback) {
              callback(null, characteristics);
            }

            setImmediate(function() {
              self.emit('characteristicsDiscover', characteristics);
              peripheral.emit('characteristicsDiscover', characteristics);
            });
          }
        }
      });

      this.messenger.discoverAllAttributes(peripheral, function(err, response) {
        // If there was a problem with the request
        if (err) {
          // Call callback immediately
          return callback && callback(err);
        }
      }.bind(this));
    }
  }.bind(this));
};

// TODO: Make work with actual array
BluetoothController.prototype.discoverCharacteristics = function(peripheral, uuids, callback) {
  // Somehow assemble the functions such that the next element is the callback to the previous
  var funcs = [];
  for (var i = 0; i < uuids.length; i++) {
    funcs.push(this.discoverCharacteristic.bind(this, peripheral, new UUID(uuids[i])));
  }

  async.series(funcs, function(err, characteristics) {

    var ret = [];

    // Weed out any characteristics that weren't found
    for (var j in characteristics) {
      if (characteristics[j]) {
        ret.push(characteristics[j]);
      }
    }

    if (callback) {
      callback(err, ret);
    }

    if (!err && ret.length) {
      setImmediate(function() {
        this.emit('characteristicsDiscover', ret);
        peripheral.emit('characteristicsDiscover', ret);
      }.bind(this));
    }

  }.bind(this));
};

BluetoothController.prototype.discoverCharacteristic = function(peripheral, characteristicUUID, callback) {

  var self = this;
  var ret = [];
  var listener = this.createCharacteristicFromAttributeValue.bind(this, peripheral, ret);

  this.on('attributeValue', listener);

  function charDiscoveryComplete(procedure) {
    if (procedure.connection === peripheral.connection) {
      self.removeListener('attributeValue', listener);
      self.removeListener('completedProcedure', charDiscoveryComplete);

      if (procedure.result != 0) {
        if (procedure.result.message === "Attribute Not Found") {
          if (callback) {
            callback(null, null);
          }
          return;
        } else {
          if (callback) {
            callback(procedure.result);
          }
          return;
        }
      } else {

        if (ret.length != 1) {
          if (callback) {
            callback(null, null);
          }
          return;
        } else {
          self.discoverCharacteristicUUID(peripheral, ret[0], callback);
        }
      }
    }
  }

  this.on('completedProcedure', charDiscoveryComplete);

  // Request only the value of the characteristic with this handle
  this.messenger.discoverCharacteristicsInRangeForUUID(peripheral, 0x0001, 0xFFFF, characteristicUUID, function(err, response) {
    // If there was a problem with the request
    if (err) {
      // Call callback immediately
      return callback && callback(err);
    }
  }.bind(this));
};

BluetoothController.prototype.discoverCharacteristicUUID = function(peripheral, characteristic, callback) {

  // Save reference to self
  var self = this;

  function setCharacteristicUUID(info) {

    // If this is for the correct connection and char handle
    if (peripheral.connection === info.connection && characteristic.handle === info.chrhandle) {

      // Set the uuid of this characteristic
      characteristic.setUUID(new UUID(info.uuid));

      // Sync the new one with the correct service
      peripheral.syncCharacteristic(characteristic);

      // Remove this listener
      self.removeListener('findInformationFound', setCharacteristicUUID);
    }
  }

  // Once we have found info containing UUID about this char
  this.on('findInformationFound', setCharacteristicUUID);

  function procedureComplete(procedure) {

    // If this was called for this peripheral
    if (procedure.connection === peripheral.connection) {

      // Stop listening for more characteristics
      self.removeListener('completedProcedure', procedureComplete);

      // If it didn't succeed
      if (procedure.result != 0) {

        // Call the callback with the error
        if (callback) {
          callback(procedure.result, null);
        }
      } else {
        // Call the callback with result
        if (callback){
          callback(null, characteristic);
        }
      }
    }
  }

  // Once we complete the search
  this.on('completedProcedure', procedureComplete);

  // Tell the messenger to begin the search for the uuid of this characteristic
  this.messenger.discoverCharacteristicUUID(characteristic, function(err, response) {
  // If there was a problem with the request
    if (err) {
      // Call callback immediately
      if (callback){
        callback(err);
      }
    }
  }.bind(this));
};

/*
* Method for turning a bit of information into a characteristic. Must discover all services before calling. (sucks, I know)
*/
BluetoothController.prototype.discoverAllServicesAndCharacteristics = function(peripheral, callback) {

  // Discover all characteristics already requires a discovery of all services
  this.discoverAllCharacteristics(peripheral, function(err, characteristics) {
    if (err) {
      // If there is an error
      // Call the callback
      if (callback) {
        callback(err);
      }
    } else {
      // If there is no error
      // Services to return
      var services = [];

      // For each service in this peripheral
      for (var service in peripheral.services) {
        // Push it into the array
        services.push(peripheral.services[service]);
      }
      // Call callback with our results
      if (callback) {
        callback(err, {services : services, characteristics : characteristics});
      }
    }
  }.bind(this));
};

BluetoothController.prototype.createCharacteristicFromInformationFound = function(peripheral, ret, info) {
  if (peripheral.connection === info.connection) {
    // Turn the uuid into a string
    var uuid = new UUID(info.uuid);

    // If this uuid isn't a service or a descriptor, or any other generic type
    if (!peripheral.services[uuid.toString()] &&
        !Service.isStandardService(uuid.toString()) &&
        !(Descriptor.isStandardDescriptor(uuid.toString())) &&
        !attributes[uuid.toString()]) {

      // Make a new one
      var characteristic = new Characteristic(peripheral, uuid, info.chrhandle);

      // Sync the new one with the correct service
      peripheral.syncCharacteristic(characteristic);

      // Push it into the return array
      ret.push(characteristic);
    }
  }
};

BluetoothController.prototype.createCharacteristicFromAttributeValue = function(peripheral, ret, value) {
  // If this is the correct connection
  if (peripheral.connection === value.connection) {
    // Create the characteristic
    var characteristic = new Characteristic(peripheral, null, value.atthandle, value.value);
    // Add to the characteristics we will report as having discovered
    ret.push(characteristic);
  }
};

BluetoothController.prototype.discoverAllCharacteristicsOfService = function(service, callback) {
  this.discoverCharacteristicsOfService(service, [], callback);
};

// TODO: This currently writes new characteristics over old ones because we have no way of
// checking which characteristics we should construct and what we shouldn't
BluetoothController.prototype.discoverCharacteristicsOfService = function(service, filter, callback) {

  // Discover the characteristics of this specific service
  this.serviceCharacteristicDiscovery(service, function(err, allCharacteristics) {
    // Format results and report any errors
    this.attributeDiscoveryHandler(err, filter, allCharacteristics, function(err, characteristics) {

      // Call that callback
      if (callback) {
        callback(err, characteristics);
      }
      // If we have characteristics to report
      if (characteristics.length) {
        // Also emit it from appropriate sources
        setImmediate(function() {
          this.emit('characteristicsDiscover', characteristics);
          service._peripheral.emit('characteristicsDiscover', characteristics);
          service.emit('characteristicsDiscover', characteristics);
        }.bind(this));
      }
    }.bind(this));
  }.bind(this));
};

BluetoothController.prototype.serviceCharacteristicDiscovery = function(service, callback) {
  // Save reference to self
  var self = this;

  var characteristics = [];

  var listener = this.createCharacteristicFromInformationFound.bind(this, service._peripheral, characteristics);

  // Once we have found info containing UUID about this char
  this.on('findInformationFound', listener);

  // Once we complete the search
  this.on('completedProcedure', function procedureComplete(procedure) {

    // If this was called for this peripheral
    if (procedure.connection === service._peripheral.connection) {

      // Stop listening for more characteristics
      self.removeListener('completedProcedure', procedureComplete);
      self.removeListener('findInformationFound', listener);

      // If it didn't succeed
      if (procedure.result != 0) {

        // Call the callback with the error
        if (callback) {
          callback(procedure.result, null);
        }
      } else {
        // Call the callback with result
        if (callback){
          callback(null, characteristics);
        }
      }
    }
  });

  // Tell the messenger to begin the search for the uuid of this characteristic
  this.messenger.discoverCharacteristicsInRange(service._peripheral, service._startHandle, service._endHandle, function(err, response) {
  // If there was a problem with the request
    if (err) {
      // Call callback immediately
      if (callback) {
        callback(err);
      }
    }
  }.bind(this));
};

BluetoothController.prototype.read = function(characteristic, callback) {
  this.readAttribute(characteristic, function(err, value) {
    characteristic.value = value;

    if (callback) {
      callback(err, value);
    }

    if (value) {
      this.emit('characteristicRead', characteristic, value);
      characteristic._peripheral.emit('characteristicRead', characteristic, value);
      characteristic.emit('characteristicRead', value);
    }
  }.bind(this));
};

BluetoothController.prototype.readAttribute = function(attribute, callback) {

  var readNum = 0;

  var self = this;

  var ret;

  function valueListener(reading) {
    // If this is our first read of several or if this will be the only read
    if (readNum === 0 || (reading.type == 0)) {
      // Assign the value
      ret = reading.value;
    } else {
      // Concat the buffers
      ret = Buffer.concat([ret, reading.value]);
    }
    readNum++;
  }

  this.on('attributeValue', valueListener);

  function attributeReadComplete(procedure) {

    // If this was called for this peripheral
    if (procedure.connection === attribute._peripheral.connection) {

      // Stop listening for more characteristics
      self.removeListener('attributeValue', valueListener);
      self.removeListener('completedProcedure', attributeReadComplete);

      // If it didn't succeed
      if (procedure.result != 0) {
        if (callback) {
          callback(procedure.result, null);
        }
      } else {
        // Call the callback
        if (callback) {
          callback(null, ret);
        }
      }
    }
  }

  // The 'completed Procedure' event is called when we're done looking for services
  this.on('completedProcedure', attributeReadComplete);

    // Request the messenger to start discovering services
  this.messenger.readHandle(attribute._peripheral, attribute, function(err, response) {
    // If there was a problem with the request
    if (err) {
      // Call callback immediately
      if (callback) {
        callback(err);
      }
    }
  }.bind(this));
};


BluetoothController.prototype.write = function(characteristic, value, callback) {
  this.writeAttribute(characteristic, value, function(err, written) {

    if (callback) {
      callback(err, written);
    }

    if (!err) {
      setImmediate(function() {
        this.emit('characteristicWrite', characteristic, written);
        characteristic._peripheral.emit('characteristicWrite', characteristic, written);
        characteristic.emit('write', written);
      }.bind(this));
    }
  }.bind(this));
};

BluetoothController.prototype.writeAttribute = function(attribute, value, callback) {

  // if (value.length > 98) {
  //   return callback && callback(new Error("Writes must be less than or equal to 98 bytes"));
  // }

  // Write has to be in 20 byte increments
  var self = this;
  this.splitWriteIntoBuffers(value, function(err, buffers) {
    if (err) {
      if (callback) {
        callback(err);
      }
      return;
    } else {
      // If there is only one buffer
      if (buffers.length == 1) {
        // We can send it immediately
        self.writeAttributeImmediately(attribute, buffers[0], callback);
      } else {
        // If there are multiple buffers, we've got to prepare several writes, then execute
        self.prepareAttributeWrite(attribute, buffers, callback);
      }
    }
  });
};

BluetoothController.prototype.writeAttributeImmediately = function(attribute, singleBuffer, callback) {
  // The 'completed Procedure' event is called when we're done writing
  this.once('completedProcedure', function(procedure) {

    // If this was called for this peripheral
    if (procedure.connection === attribute._peripheral.connection &&
          procedure.chrhandle === attribute.handle) {

      // If it didn't succeed
      if (procedure.result != 0) {

        if (callback) {
          callback(procedure.result, null);
        }
      } else {
        // Call the callback
        if (callback) {
          callback(null, singleBuffer);
        }
      }
    }
  }.bind(this));

  this.messenger.writeAttributeImmediately(attribute, singleBuffer, function(err, response) {
    // If there was a problem with the request
    if (err) {
      // Call callback immediately
      return callback && callback(err);
    }
  });
};

BluetoothController.prototype.prepareAttributeWrite = function(attribute, multipleBuffers, callback) {
  var bufSize = 20;
  var offset = 0;

  // Keep this around
  var self = this;

  function bufferWriteIterate(procedure) {
    // If this is for our connection
    if (procedure.connection === attribute._peripheral.connection && procedure.chrhandle === attribute.handle) {
      // If there was an error, report it and cancel write
      if (procedure.result != 0) {
        // Cancel any previous writes
        self.messenger.cancelWrite(attribute, function(cancelErr, response) {
          // Call callback immediately
          return callback && callback(procedure.result);
        });
      } else {
        // If there was no error
        // If we've completed the procedure but still have more to write
        if (offset < multipleBuffers.length) {

          // Send another part of the buffer off
          self.messenger.prepareWrite(attribute, multipleBuffers[offset], offset*bufSize, function(err, response) {
            // If there was a problem with the request
            if (err) {
              // Cancel any previous writes
              self.messenger.cancelWrite(attribute, function(cancelErr, response) {

                // Call callback immediately
                return callback && callback(err);
              });
            }
            // Increment offset so we send the next buffer next time
            offset++;
          });
        } else if (offset === multipleBuffers.length) {
          // If we've sent all the prepare writes...
          // Remove the buffer write iterator listener so we don't send any more packets
          self.removeListener('completedProcedure', bufferWriteIterate);

          // Once our write execution is complete
          self.once('completedProcedure', function(procedure) {
            // If there was an error
            if (procedure.result != 0) {
              // Report the error
              if (callback) {
                callback(procedure.result);
              }
            } else {
              // If there was no error
              //Concat all the buffers into one
              var ret = multipleBuffers[0];
              for (var i = 1; i < multipleBuffers.length; i++) {
                ret = Buffer.concat([ret, multipleBuffers[i]]);
              }

              // Call callback
              if (callback) {
                callback(null, ret);
              }
            }
          });
          // Execute the write of the packets
          self.messenger.executeWrite(attribute, function(err, response) {
            // If there was a problem with the request
            if (err) {
              // Call callback immediately
              if (callback) {
                callback(err);
              }
              return;
            }
          });
        }
      }
    }
  }

  // Function for writing each subsequent buffer
  this.on('completedProcedure', bufferWriteIterate);

  this.messenger.prepareWrite(attribute, multipleBuffers[offset], offset * bufSize, function(err, response) {
    // If there was a problem with the request
    if (err) {
      // Call callback immediately
      return callback && callback(err);
    }
    offset++;
  });
};

BluetoothController.prototype.splitWriteIntoBuffers = function(value, callback) {
  // If nothing was passed in, just return an error
  if (!value) {
    return callback && callback(new Error("No value passed to write function"));
  } else {
    // If something was passed in
    var buf;
    if (typeof value === "string") {
      // If it is a string, make a buf with utf-8 encoding
      buf = new Buffer(value);
    } else if (Buffer.isBuffer(value)) {
      // If it's already a buffer, keep as is
      buf = value;
    } else if (!isNaN(value)) {
      // If it's a number, make a new buffer for the 32 bit number
      buf = new Buffer(4);
      buf.writeUInt32BE(value, 0);
    } else {
      // If none of the above, it's invalid. Throw an error
      if (callback) {
        callback(new Error("Can only write strings, numbers, and buffers.")); // TODO: should this be a new Error?
      }
      return;
    }

    // Max number of bytes per buffer
    var maxBufLen = 20;
    var maxNumBufs = 5;

    // Get the number of buffers we'll need
    var iter = Math.ceil(buf.length/maxBufLen);

    // Prepare array for buffers
    var ret = new Array(iter);
    // For each buffer
    for (var i = 0; i < iter; i++) {
      // Grab the start byte
      var start = i * maxBufLen;
      // Put that start plus next 20 bytes (or if it's the last, just grab remainder)
      var end;
      if (i == (iter-1)) {
        end = buf.length;
      } else {
        end = start + maxBufLen;
      }
      // Slice it and throw it into our return array
      ret[i] = buf.slice(start, end);
    }

    // Return array
    if (callback){
      callback(null, ret);
    }
  }
};

// Continues reading and storing subsequent handles of a characteristic until a non-descriptor is found
BluetoothController.prototype.discoverDescriptorsOfCharacteristic = function(characteristic, callback) {
  var self = this;
  var descriptors = [];
  var offset = 1;
  var done = false;

  function findDescriptorInformation(info) {
    // If this for the correct connection
    if (characteristic._peripheral.connection === info.connection) {
      // Turn the uuid into a string
      var uuid = new UUID(info.uuid);

      // If this uuid isn't of a descriptor
      if (Descriptor.isStandardDescriptor(uuid.toString())) {

        // Make a new one
        var descriptor = new Descriptor(characteristic._peripheral, uuid, info.chrhandle);

        // Add it to the characteristic's descriptors
        characteristic.descriptors[uuid.toString()] = descriptor;

        // Push it into the return array
        descriptors.push(descriptor);
      } else {
        // Set the done flag
        done = true;

        // Remove this listener
        self.removeListener('findInformationFound', findDescriptorInformation);
      }
    }
  }

  // Keep reading the next handle until it is not a descriptor
  this.on('findInformationFound', findDescriptorInformation);

  function descriptorDiscoveryComplete(procedure) {
    // If this was called for this peripheral
    if (procedure.connection === characteristic._peripheral.connection) {

      // If it didn't succeed
      if (procedure.result != 0) {
        // If the error is not that their is no Attribute found (which will happen
        // if the final characteristic is called upon)
        if (procedure.result.message != 'Attribute Not Found') {
          // Call the callback with the error
          if (callback) {
            callback(procedure.result, null);
          }
          // Emit the event
          setImmediate(function() {
            self.emit('error', procedure.result);
          });
          return;
        } else {
          done = true;
        }
      }

      // If we have finished finding all descriptors
      if (done) {
        // Stop listening for more descriptors
        self.removeListener('completedProcedure', descriptorDiscoveryComplete);

        // Call the callback with result
        if (callback) {
          callback(null, descriptors);
        }

        // Emit events
        setImmediate(function() {
          self.emit('descriptorsDiscover', descriptors);
          characteristic._peripheral.emit('descriptorsDiscover', descriptors);
        });
      } else {
        // If we have not finished finding descriptors

        // Increase the offset
        offset++;

        // And make the call for the next attribute
        self.messenger.findHandle(characteristic._peripheral, characteristic.handle + offset, function(err, response) {
          // If there was a problem with the request
          if (err) {

          // Call callback immediately
          if (callback) {
            callback(err);
          }

           setImmediate(function() {
             self.emit('error', err);
           });
          }
        });
      }
    }
  }

  // Once we have finished finding a single descriptor
  this.on('completedProcedure', descriptorDiscoveryComplete);

  // Read the first subsequent handle
  this.messenger.findHandle(characteristic._peripheral, characteristic.handle + offset, function(err, response) {
    // If there was a problem with the request
    if (err) {

      // Call callback immediately
      if (callback) {
        callback(err);
      }

      // Emit the error
      setImmediate(function() {
        this.emit('error', err);
      }.bind(this));
    }
  }.bind(this));
};

BluetoothController.prototype.readDescriptor = function(descriptor, callback) {
  this.readAttribute(descriptor, function(err, value) {
    descriptor.value = value;

    if (callback) {
      callback(err, value);
    }

    if (value) {
      setImmediate(function() {
        this.emit('descriptorRead', descriptor, value);
        descriptor._peripheral.emit('descriptorRead', descriptor, value);
        descriptor.emit('descriptorRead', value);
      }.bind(this));
    }
  }.bind(this));
};

BluetoothController.prototype.writeDescriptor = function(descriptor, value, callback) {
  this.writeAttribute(descriptor, value, function(err, written) {

    if (callback) {
      callback(err, written);
    }

    if (!err) {
      setImmediate(function() {
        this.emit('descriptorWrite', descriptor, written);
        descriptor._peripheral.emit('descriptorWrite', descriptor, written);
        descriptor.emit('descriptorWrite', written);
      }.bind(this));
    }
  }.bind(this));
};

BluetoothController.prototype.notify = function(characteristic, notify, callback) {
  if (notify) {
    this.startNotifications(characteristic, callback);
  } else {
    this.stopNotifications(characteristic, callback);
  }
}

BluetoothController.prototype.startNotifications = function(characteristic, callback) {
  this.writeToConfigDescriptorOfCharacteristic(characteristic, new Buffer([0x01, 0x00]), function(err) {
    if (callback) {
      callback(err);
    }
  });
};

BluetoothController.prototype.stopNotifications = function(characteristic, callback) {
  this.stopRemoteUpdates(characteristic, callback);
};

BluetoothController.prototype.startIndications = function(characteristic, callback) {
  this.writeToConfigDescriptorOfCharacteristic(characteristic, new Buffer([0x02, 0x00]), function(err) {
    if (callback) {
      callback(err);
    }
  });
};

BluetoothController.prototype.stopIndications = function(characteristic, callback) {
  this.stopRemoteUpdates(characteristic, callback);
};

BluetoothController.prototype.stopRemoteUpdates = function(characteristic, callback) {
  this.writeToConfigDescriptorOfCharacteristic(characteristic, new Buffer([0x00, 0x00]), function(err) {
    if (callback) {
      callback(err);
    }
  });
};

BluetoothController.prototype.writeToConfigDescriptorOfCharacteristic = function(characteristic, value, callback) {
  // Check if we've already fetched the config descriptor
  this.retrieveConfigDescriptor(characteristic, function(err, descriptor) {
    if (err) {
      return callback && callback(err);
    } else {
      if (!descriptor) {
        return callback && callback(new Error("Characteristic is not configured for notifications"));
      } else {
        descriptor.write(value, function(err, written) {
          if (callback) {
            callback(err);
          }
          return;
        });
      }
    }
  });
};

BluetoothController.prototype.retrieveConfigDescriptor = function(characteristic, callback) {
  // Check if we've already fetched the config descriptor
  this.getConfigDescriptorFromFetched(characteristic, function(descriptor) {
    // If we haven't
    if (!descriptor) {
      // Discover all descriptors
      this.discoverDescriptorsOfCharacteristic(characteristic, function(err, descriptors) {
        if (err) {
          if (callback) {
            callback(err);
          }
          return;
        } else {
          // Now check again for the config descriptor
          this.getConfigDescriptorFromFetched(characteristic, function(descriptor) {
            // If there is no descriptor, you can't get notifications from this char
            if (!descriptor) {
              return callback && callback();
            } else {
              return callback && callback(null, descriptor);
            }
          }.bind(this));
        }
      }.bind(this));
    } else {
      if (callback) {
        callback(null, descriptor);
      }
      return;
    }
  }.bind(this));
};

BluetoothController.prototype.getConfigDescriptorFromFetched = function(characteristic, callback) {
  for (var d in characteristic.descriptors) {
    if (characteristic.descriptors[d].uuid.toString() == "2902") {
      return callback && callback(characteristic.descriptors[d]);
    }
  }
  if (callback) {
    callback();
  }
};

BluetoothController.prototype.confirmIndication = function(characteristic, callback) {
  this.messenger.confirmIndication(characteristic, function(err, response) {
    // If there was a problem with the request
    if (err) {
      // Call callback immediately
      if (callback) {
        callback(err);
      }

      // Emit the error
      setImmediate(function() {
        this.emit('error', err);
      }.bind(this));
    }
  }.bind(this));
};

BluetoothController.prototype.updateRssi = function(peripheral, callback) {
  this.messenger.updateRssi(peripheral, function(err, response) {
    if (callback) {
      callback(err, response.rssi);
    }
    if (!err) {
      setImmediate(function() {
        this.emit('rssiUpdate', response.rssi);
        peripheral.emit('rssiUpdate', response.rssi);
      }.bind(this));
    }
  }.bind(this));
};

// TODO Returns a string... is that appropriate?
BluetoothController.prototype.getBluetoothAddress = function(callback) {
  this.messenger.getAddress(function(err, response) {
    var address;
    if (response && !err) {
      address = Address.bufToStr(response.address);
    }
    if (callback) {
      callback(err, address);
    }
  });
};

BluetoothController.prototype.getMaxConnections = function(callback) {
  this.messenger.getMaxConnections(function(err, response) {
    if (callback) {
      callback(err, response.maxconn);
    }
  });
};

BluetoothController.prototype.startAdvertising = function(callback) {
  this.messenger.startAdvertising(this._userAdvData, function(err, response) {
    if (!err) {
      this.advertising = true;
      // Emit the error
      setImmediate(function() {
        this.emit('startAdvertising');
      }.bind(this));
    } else {
      this.advertising = false;
      // Emit the error
      setImmediate(function() {
        this.emit('error', err);
      }.bind(this));
    }

    // Call callback immediately
    if (callback) {
      callback(err);
    }
  }.bind(this));
};

BluetoothController.prototype.stopAdvertising = function(callback) {
  this.messenger.stopAdvertising(function(err, response) {
    if (!err) {
      this.advertising = false;
      // Emit the error
      setImmediate(function() {
        this.emit('stopAdvertising');
      }.bind(this));
    } else {
      this.advertising = true;
      // Emit the error
      setImmediate(function() {
        this.emit('error', err);
      }.bind(this));
    }

    // Call callback immediately
    if (callback) {
      callback(err);
    }
  }.bind(this));
};

BluetoothController.prototype.setAdvertisingData = function(data, callback) {
  this.advDataHelper(data, 0, callback);
};

BluetoothController.prototype.setScanResponseData = function(data, callback) {
  this.advDataHelper(data, 1, callback);
};

BluetoothController.prototype.advDataHelper = function(data, advParam, callback) {
  if (data.length > 32){
    callback && callback(new Error("Advertisement packet exceeds maximum length of 32 bytes."));
  } else {
    this.messenger.setAdvertisementData(advParam, data, function(err, response) {

      if (err) {
        setImmediate(function() {
          this.emit('error');
        }.bind(this));
        this._userAdvData = false;
        callback && callback(err);
      } else {
        this._userAdvData = true;
        callback && callback(null);
      }

    }.bind(this));
  }
};

BluetoothController.prototype.getFirmwareVersion = function(callback) {
  this.messenger.readLocalHandle(this._firmwareVersionHandle, 0, function(err, response) {
    var version;
    if (response.value) {
      version = response.value.toString();
    }
    if (callback) {
      callback(err, version);
    }
  });
};

BluetoothController.prototype.maxNumValues = function(callback) {
  this.getFirmwareVersion(function(err, version) {
    var max;
    if (!err) {
      max = this._maxNumValues[version];
    }
    if (callback) {
      callback(err, max);
    }
  }.bind(this));
};

BluetoothController.prototype.readLocalValue = function(index, offset, callback) {
  this.readLocalHandle(this._localHandles[index], offset, callback);
};

BluetoothController.prototype.writeLocalValue = function(index, data, callback) {
  if (!Buffer.isBuffer(data)) {
    if (callback) {
      callback(new Error("Value must be a buffer."));
    }
    return;
  }
  this.writeLocalHandle(this._localHandles[index], data, callback);
};

BluetoothController.prototype.readLocalHandle = function(handle, offset, callback) {
  this.messenger.readLocalHandle(handle, offset, function(err, response) {
    if (callback) {
      callback(err, response.value);
    }
  });
};

BluetoothController.prototype.writeLocalHandle = function(handle, data, callback) {
  this.messenger.writeLocalHandle(handle, data, function(err, response) {
    err = err ? err : response.result;
    if (callback) {
      callback(err);
    }
  });
};

/*
* HARDWARE
*/

BluetoothController.prototype.I2C = function(address) {
  return new BluetoothI2C(this.messenger, address);
};

// TODO What is this global function doing floating around here?
function BluetoothI2C(messenger, address) {
  this.messenger = messenger;
  this.address = address << 1;
}

BluetoothI2C.prototype.transfer = function(txbuf, rxLen, callback) {
  this.send(txbuf, function(err) {
    if (err) {
      if (callback) {
        callback(err);
      }
      return;
    } else {
      this.receive(rxLen, function(err, rx) {
        if (callback) {
          callback(err, rx);
        }
        return;
      });
    }
  }.bind(this));
};

BluetoothI2C.prototype.send = function(txbuf, callback) {
  // Send off the data
  // TODO: Let users decide on stop condition
  this.messenger.I2CSend(this.address, 1, txbuf, function(err, response) {

    // Return the error
    if (callback) {
      callback(err);
    }
  });
};

BluetoothI2C.prototype.receive = function(length, callback) {
  this.messenger.I2CRead(this.address, 1, length, function(err, response) {
    if (callback) {
      callback(err, response.data);
    }
  });
};

BluetoothController.prototype.gpio = function(index) {
  if (!this.gpios) {
    this.createGPIOs();
  }
  return this.gpios[index];
};

BluetoothController.prototype.createGPIOs = function() {
  this.gpios = {};
  this.gpios.p0_3 = new BluetoothPin(this, 0, 3);
  this.gpios.p0_2 = new BluetoothPin(this, 0, 2);
};

function BluetoothPin(controller, port, pin) {
  this._port = port;
  this._pin = pin;
  this._controller = controller;
  this.direction = "input";
  this.value = false;
  this.interruptOn = null;
}

util.inherits(BluetoothPin, events.EventEmitter);

BluetoothPin.prototype.toString = function() {
  return JSON.stringify({
    direction: this.direction,
    value: this.value,
  });
};

BluetoothPin.prototype.setInput = function(callback) {
  this.direction = "input";
  this.setPinDirections(callback);
};

BluetoothPin.prototype.setOutput = function(initial, callback) {
  if (typeof initial == 'function') {
    next = initial;
    initial = null;
  }

  this.direction = "output";

  this.setPinDirections(function(err) {
    if (err) {
      return callback && callback(err);
    } else {
      this.write(initial, callback);
    }
  }.bind(this));
};

BluetoothPin.prototype.write = function(value, callback) {
  if (this.direction === "output") {
    this.value = value;
    this.setPinValues(value, callback);
  }
};


BluetoothPin.prototype.read = function(callback) {
  // Read port 0
  this._controller.messenger.readPin(this._port, 1 << this._pin, function(err, response) {
    var val;
    if (!err) {
      val = (response.data >> this._pin);
    }
    this.value = val;
    if (callback) {
      callback(err, val);
    }
  }.bind(this));
};

BluetoothPin.prototype.setPinDirections = function(callback) {
  var mask = 0;

  // Iterate through our gpios to construct a bitmask
  for (var id in this._controller.gpios) {
    // If the gpio is an output
    var gpio = this._controller.gpios[id];
    if (gpio.direction === "output") {
      // Put a one in it's place
      mask += (1 << gpio._pin);
    }
  }

  this._controller.messenger.setPinDirections(this._port, mask, function(err, response) {
    if (callback) {
      callback(err);
    }
  });
};

BluetoothPin.prototype.setPinValues = function(value, callback) {
  var mask = 0;
  var data = 0;

  // Iterate through our gpios to construct a bitmask
  for (var id in this._controller.gpios) {
    // If the gpio is an output
    var gpio = this._controller.gpios[id];
    if (gpio.direction === "output") {
      // Put a one in it's place
      mask += (1 << gpio._pin);
      // If the value is high
      if (gpio.value == true) {
        // Put a 1 in it's place
        data += (1 << gpio._pin);
      }
    }
  }

  this._controller.messenger.writePin(this._port, mask, data, function(err, response) {
    if (callback) {
      callback(err);
    }
  });
};

BluetoothPin.prototype.watch = function(type, callback) {

  if (type != "rise" && type != "fall" && type !="change") {
    return callback && callback(new Error("Invalid pin watch type. Must be 'rise', 'fall', or 'change'."));
  }

  // Set an event listener
  this.on(type, callback);

  // Set the type for the pin
  this.onInterrupt = type;

  this.setPinWatches(type, function(err) {
    if (err) {
      if (callback) {
        callback(err);
      }
    }
  }.bind(this));
};

BluetoothPin.prototype.unwatch = function(type, callback) {
  if (this.onInterrupt === type) {
    this.onInterrupt = null;
    this.setPinWatches(type, callback);
  } else {
    if (callback) {
      callback();
    }
  }
};

BluetoothPin.prototype.setPinWatches = function(type, callback) {
  var mask = 0;
  // For each of our gpios
  for (var id in this._controller.gpios) {
    // Get reference to gpio
    var gpio = this._controller.gpios[id];
    // If this interrupt type is the kind we are watching for
    if (gpio.onInterrupt == type) {
      // Add it to the mask
      mask += (1 << gpio._pin);
    }
  }

  // Tell the messenger to set the mask
  this._controller.messenger.watchPin(0, mask, (type === "rise" ? 0 : 1), function(err, response) {
    // If we're  looking for a change
    if (type === "change") {
      // We'll have to set the rise detector as well
      this._controller.messenger.watchPin(0, mask, 0, function(err, response) {
        if (callback) {
          callback(err);
        }
      });
    } else {
      if (callback) {
        callback(err);
      }
    }
  }.bind(this));
};

BluetoothController.prototype.readADC = function(callback) {
  this.once('ADCRead', function(adc) {
    /* From the datasheet:
    In the example case of 12 effective bits decimation, you will need to read
    the left-most 12 bits of the value to interpret it. It is a 12-bit 2's
    complement value left-aligned to the MSB of the 16-bit container.
    */
    var normalized = (adc.value >> 4) / 0x7ff;
    if(callback) {
      callback(null, normalized);
    }
  });
  // Read ADC channel 1, with the third option for decimation (12 value) with
  // aref as reference
  this.messenger.readADC(0x1, 0x3, 0x2, function(err, response) {

    // If there was a problem with the request
    if (err) {
      // Call callback immediately
      if (callback) {
        callback(err);
      }

      // Emit the error
      setImmediate(function() {
        this.emit('error', err);
      }.bind(this));
    }
  }.bind(this));
};

// Set whether a we can be bonded to
BluetoothController.prototype.setBondable = function(bondable, callback) {
  this.messenger.setBondable(bondable ? 1 : 0, callback);
};

// Get bonds with current devices
BluetoothController.prototype.getBonds = function(callback) {
  var bonds = [];
  var numBondsToSatisfy = 0;
  this.on('bondStatus', function bondStatus(status) {
    bonds.push(status);

    if (bonds.length === bumBondsToSatisfy) {
      this.removeListener('bondStatus', bondStatus);
      if (callback) {
        callback(null, bonds);
      }
    }
  }.bind(this));

  this.messenger.getBonds(function (err, response) {
    if (err) {
      if (callback) {
        callback(err);
      }
    } else if (response.bonds === 0) {
      if (callback) {
        callback(null, bonds);
      }
    } else {
      numBondsToSatisfy = response.bonds;
    }
  });
};

// Delete any bonds with devices
BluetoothController.prototype.deleteBond = function(peripheral, callback) {
  this.messenger.deleteBond(peripheral, function(err) {
    if (!err) {
      peripheral.bondHandle = 0xff;
    }
    if (callback){
      callback(err);
    }
  });
};

BluetoothController.prototype.startEncryption = function(peripheral, callback) {
  var self = this;

  function successHandler(status) {
    if (status.connection === peripheral.connection) {
      peripheral.bondHandle = status.bonding;
      removeHandlers();
      if (callback) {
        callback(null, peripheral.bondHandle);
      }
    }
  }

  function failHandler(failDetails) {
    if (peripheral.connection === failDetails.handle) {
      removeHandlers();
      if (callback) {
        callback(failDetails.reason);
      }
    }
  }

  function removeHandlers() {
    self.removeListener('connectionStatus', successHandler);
    self.removeListener('bondingFail', failHandler);
  }

  this.on('connectionStatus', successHandler);
  this.on('bondingFail', failHandler);

  this.messenger.startEncryption(peripheral, true, function(err, response) {
    if (err) {
      if (callback) {
        callback(err);
      }
    }
  });
};

BluetoothController.prototype.enterPasskey = function(peripheral, passKey, callback) {
  if (passKey < 0 || passkey > 999999) {
    return callback && callback(new Error("Passkey must be between 0 and 999999 inclusive."));
  } else {
    this.messenger.enterPasskey(peripheral, passKey, callback);
  }
};

BluetoothController.prototype.setEncryptionSize = function(size, callback) {
  // Enable/disable protection, set same key size, no smp io input/output
  if (size < 7 || size > 16) {
    return callback && callback(new Error("Invalid encryption key size. Must be between 7 and 16 bytes"));
  } else {
    this.messenger.setSecurityParameters(this._MITMEnabled ? 1 : 0, size, 3, function(err, response) {
      if (!err) {
        this._minKeySize = size;
      }
      if (callback) {
        callback(err);
      }
    });
  }
};

BluetoothController.prototype.setOOBData = function(data, callback) {
  if (!Buffer.isBuffer(data) || (data.length != 0 && data.length != 16)) {
    if (callback) {
      callback(new Error("OOB Data must be a buffer of 0 or 16 octets long"));
    }
    return;
  } else {
    this.messenger.setOOBData(data, callback);
  }
};

BluetoothController.prototype.enableMITMProtection = function(enable, callback) {
  // Enable/disable protection, set same key size, no smp io input/output
  this.messenger.setSecurityParameters(enable ? 1 : 0, this._minKeySize, 3, function(err, response) {
    if (!err) {
      this._MITMEnabled = enable;
    }
    if (callback) {
      callback(err);
    }
  });
};

// Set the module port of the Bluetooth Low Energy module to initialize
function use(hardware, callback) {
  var controller = new BluetoothController(hardware, callback);
  return controller;
}

module.exports.BluetoothController = BluetoothController;
module.exports.use = use;
module.exports.profile = profile;