CAR-Forwarders

Forward MQTT messages to Websockets server and visa-versa

Smart Trolley Devices

There is a Version 1 smart trolley device, as part of the Call-A-Robot project, that sends and receives data via websockets. V2 device sends and receives using MQTT. To make both devices work V2 messages are forwarded to websockets. In the future presumably all devices will use MQTT.

Two Daemons

MtoW.py Listens on all topics listed in Config.py sent to the MQTT host. It then adds a dictionary message field of 'Forwarded-by: MtoW.py" and sends this message to the Websocket host named within Config.py. Some topic messages are re-formatted.

WtoM.py Listens to Websocket host named in Config.py for order-update messages and then sends to MQTT host. Not completed

RUN

1. python MtoW.py
2. python WtoM.py

Both run as daemons

Future

1. Which messages have been forwarded will be stored and saved to a locked file so multiple daemons can be run concurrently without resending a message twice

Libraries / Package requirements

• import websocket
• import rel
• import paho.mqtt.client as mqtt
• from websocket import create_connection
• import json

Config.py

Not saved within repo as it has password

MQTT_USER = '*****'

MQTT_PASSWORD = '**********'

MQTT_HOST = 'MQTT server host'

MQTT_PORT = 8097

Topics as a list

MQTT_TOPICS = ['trolley/gps', 'trolley/battery', 'trolley/method', 'trolley/registration', 'trolley/status']

WS_HOST = 'wss://host name'

MQTT_LISTEN_TOPIC = 'trolley/status'