gattacker/lib/noble/examples/pizza/central.js

GATTacker

var noble = require('../..');
var pizza = require('./pizza');

var pizzaServiceUuid = '13333333333333333333333333333337';
var pizzaCrustCharacteristicUuid = '13333333333333333333333333330001';
var pizzaToppingsCharacteristicUuid = '13333333333333333333333333330002';
var pizzaBakeCharacteristicUuid = '13333333333333333333333333330003';

noble.on('stateChange', function(state) {
  if (state === 'poweredOn') {
    //
    // Once the BLE radio has been powered on, it is possible
    // to begin scanning for services. Pass an empty array to
    // scan for all services (uses more time and power).
    //
    console.log('scanning...');
    noble.startScanning([pizzaServiceUuid], false);
  }
  else {
    noble.stopScanning();
  }
})

var pizzaService = null;
var pizzaCrustCharacteristic = null;
var pizzaToppingsCharacteristic = null;
var pizzaBakeCharacteristic = null;

noble.on('discover', function(peripheral) {
  // we found a peripheral, stop scanning
  noble.stopScanning();

  //
  // The advertisment data contains a name, power level (if available),
  // certain advertised service uuids, as well as manufacturer data,
  // which could be formatted as an iBeacon.
  //
  console.log('found peripheral:', peripheral.advertisement);
  //
  // Once the peripheral has been discovered, then connect to it.
  // It can also be constructed if the uuid is already known.
  ///
  peripheral.connect(function(err) {
    //
    // Once the peripheral has been connected, then discover the
    // services and characteristics of interest.
    //
    peripheral.discoverServices([pizzaServiceUuid], function(err, services) {
      services.forEach(function(service) {
        //
        // This must be the service we were looking for.
        //
        console.log('found service:', service.uuid);

        //
        // So, discover its characteristics.
        //
        service.discoverCharacteristics([], function(err, characteristics) {

          characteristics.forEach(function(characteristic) {
            //
            // Loop through each characteristic and match them to the
            // UUIDs that we know about.
            //
            console.log('found characteristic:', characteristic.uuid);

            if (pizzaCrustCharacteristicUuid == characteristic.uuid) {
              pizzaCrustCharacteristic = characteristic;
            }
            else if (pizzaToppingsCharacteristicUuid == characteristic.uuid) {
              pizzaToppingsCharacteristic = characteristic;
            }
            else if (pizzaBakeCharacteristicUuid == characteristic.uuid) {
              pizzaBakeCharacteristic = characteristic;
            }
          })

          //
          // Check to see if we found all of our characteristics.
          //
          if (pizzaCrustCharacteristic &&
              pizzaToppingsCharacteristic &&
              pizzaBakeCharacteristic) {
            //
            // We did, so bake a pizza!
            //
            bakePizza();
          }
          else {
            console.log('missing characteristics');
          }
        })
      })
    })
  })
})

function bakePizza() {
  //
  // Pick the crust.
  //
  var crust = new Buffer(1);
  crust.writeUInt8(pizza.PizzaCrust.THIN, 0);
  pizzaCrustCharacteristic.write(crust, false, function(err) {
    if (!err) {
      //
      // Pick the toppings.
      //
      var toppings = new Buffer(2);
      toppings.writeUInt16BE(
        pizza.PizzaToppings.EXTRA_CHEESE |
        pizza.PizzaToppings.CANADIAN_BACON |
        pizza.PizzaToppings.PINEAPPLE,
        0
      );
      pizzaToppingsCharacteristic.write(toppings, false, function(err) {
        if (!err) {
          //
          // Subscribe to the bake notification, so we know when
          // our pizza will be ready.
          //
          pizzaBakeCharacteristic.on('read', function(data, isNotification) {
            console.log('Our pizza is ready!');
            if (data.length === 1) {
              var result = data.readUInt8(0);
              console.log('The result is',
                result == pizza.PizzaBakeResult.HALF_BAKED ? 'half baked.' :
                result == pizza.PizzaBakeResult.BAKED ? 'baked.' :
                result == pizza.PizzaBakeResult.CRISPY ? 'crispy.' :
                result == pizza.PizzaBakeResult.BURNT ? 'burnt.' :
                result == pizza.PizzaBakeResult.ON_FIRE ? 'on fire!' :
                  'unknown?');
            }
            else {
              console.log('result length incorrect')
            }
          });
          pizzaBakeCharacteristic.subscribe(function(err) {
            //
            // Bake at 450 degrees!
            //
            var temperature = new Buffer(2);
            temperature.writeUInt16BE(450, 0);
            pizzaBakeCharacteristic.write(temperature, false, function(err) {
              if (err) {
                console.log('bake error');
              }
            });
          });

        }
        else {
          console.log('toppings error');
        }
      });
    }
    else {
      console.log('crust error');
    }
  })
}