I am pretty new to MQTT and I would like to establish a connection to a digitransit mqtt broker to receive public transportation data using python paho mqtt client. To connect to a broker the port and the topic is needed.
I am not sure if something is missing. Please not that the script is executed via browser based jupyter notebook.
- Port: 8883
- Topic: /hfp/v2/journey/#
- Broker: mqtt.hsl.fi
When running via command line the data can be received, e.g.
/hfp/v2/journey/ongoing/vp/bus/0022/01281/1040/2/Elielinaukio/14:29/1140118/0//// {"VP":{"desi":"40","dir":"2","oper":22,"veh":1281,"tst":"2022-07-06T11:56:53.417Z","tsi":1657108613,"spd":null,"hdg":null,"lat":null,"long":null,"acc":null,"dl":-101,"odo":8530,"drst":0,"oday":"2022-07-06","jrn":2646,"line":62,"start":"14:29","loc":"ODO","stop":null,"route":"1040","occu":0}}
You can try this out simply using two commands:
npm install -g mqtt
mqtt subscribe -h mqtt.hsl.fi -p 8883 -l mqtts -v -t "/hfp/v2/journey/#"
When running in a browser based jupyter notebook I only see the output that is defined on_connect method but no data shows up.
My code snippet is:
# pip install paho-mqtt
import paho.mqtt.client as mqtt
# The callback for when the client receives a CONNACK response from the server.
def on_connect(client, userdata, flags, rc):
print("Connected with result code "+ str(rc))
# Subscribing in on_connect() means that if we lose the connection and
# reconnect then subscriptions will be renewed.
client.subscribe("/hfp/v2/journey/#")
# The callback for when a PUBLISH message is received from the server.
def on_message(client, userdata, msg):
print(msg.topic+" "+str(msg.payload))
client = mqtt.Client()
client.on_connect = on_connect
client.on_message = on_message
client.tls_set()
client.connect("mqtt.hsl.fi", 8883, 60)
client.loop_forever()
Does anyone know what kind of detail is wrong or missing?
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