demo.py

#!/usr/bin/env python
import uuid
import json
import time
import random

import paho.mqtt.client as mqtt

SERVER_HOST = 'example.com'
ACCESS_TOKEN = 'AccessToken='
DEVICE_ID = 'mqtt-demo-device-' + ACCESS_TOKEN[0:4]
MPU6050_ADDRESS = 0x68 # default MPU6050 address

try:
    import mpu6050
    sensor = mpu6050.mpu6050(MPU6050_ADDRESS)
    print("Using real MPU6050 sensor.")
except ImportError:
    class FakeMPU6050(object):
        def rand(self):
            return round(-0.25 + 0.5 * random.random(), 2)

        def get_temp(self):
            return 25 + self.rand()

        def get_gyro_data(self):
            return {'x': self.rand(),
                    'y': self.rand(),
                    'z': self.rand()}

        def get_accel_data(self):
            return {'x': 9.8 + self.rand(),
                    'y': self.rand(),
                    'z': self.rand()}

    sensor = FakeMPU6050()
    print("Using MPU6050 emulator.")

class MQTTDemo(object):

    def __init__(self, url, access_token, device_id):
        self._client_id = str(uuid.uuid4())
        self._connected = False
        self._device_id = device_id
        self._accessToken = access_token

        self._client = mqtt.Client(self._client_id)
        self._client.connect(url)
        self._client.on_connect = self._on_connect
        self._client.on_message = self._on_message
        self._client.on_disconnect = self._on_disconnect
        self._client.loop_start()

    def _on_connect(self, client, userdata, flags, rc):
        print('Connected with rc=%s' % rc)
        client.subscribe('dh/response/authenticate@%s' % self._client_id)
        self._publish('dh/request', {
            'action': 'authenticate',
            'token': self._accessToken,
            'requestId': str(uuid.uuid4())
        })

    def _on_message(self, client, userdata, message):
        print('New message: %s' % message.payload)
        js = json.loads(message.payload)
        if js['action'] == 'authenticate':
            if js['status'] == 'success':
                client.subscribe('dh/response/device/save@%s' % self._client_id)
                client.subscribe('dh/response/notification/insert@%s' % self._client_id)
                self._connected = True
            else:
                print("Failed to authenticate.")

    def _on_disconnect(self, client, userdata, rc):
        print('Disconnected with rc=%s' % rc)
        self._connected = False

    def _publish(self, topic, payload):
        payload['requestId'] = str(uuid.uuid4())
        self._client.publish(topic, json.dumps(payload))

    def run(self):
        while not self._connected:
            time.sleep(0.01)
        time.sleep(1.0)

        self._publish('dh/request', {
            'action': 'device/save',
            'deviceId': self._device_id,
            'device': {
                'name': self._device_id
            }
        })

        while self._connected:
            self._publish('dh/request', {
                'action': 'notification/insert',
                'deviceId': self._device_id,
                'notification': {
                    'notification': 'mpu6050',
                    'parameters':
                                {
                                    'temperature': sensor.get_temp(),
                                    'acceleration': sensor.get_accel_data(),
                                    'gyro': sensor.get_gyro_data()
                                }
                }
            })
            time.sleep(5)


if __name__ == '__main__':
    d = MQTTDemo(SERVER_HOST, ACCESS_TOKEN, DEVICE_ID)
    d.run()