[Python] Python MQTT

[fedex]

Ich möchte Temperatur Daten mit einer Callback Funktion an meinen MQTT Broker senden.

Welche Variable des example_callback scripts enthält denn die Temperaturwerte?

Mit t.CALLBACK_TEMPERATURE bekomme ich immer nur den Wert 8?

 

meine Skript sieht so aus:

 

HOST = "10.208.216.149"

PORT = 4223

UID = "t8u" # Change to your UID

 

import time

 

import paho.mqtt.client as mqtt

 

from tinkerforge.ip_connection import IPConnection

from tinkerforge.bricklet_temperature import BrickletTemperature

 

def on_connect(client, userdata, flags, rc):

    print("Connected with result code " + str(rc))

 

# Callback function for temperature callback (parameter has unit °C/100)

def cb_temperature(temperature):

    print("Temperature: " + str(temperature/100.0) + " °C")

 

   

if __name__ == "__main__":

    ipcon = IPConnection() # Create IP connection

    t = BrickletTemperature(UID, ipcon) # Create device object

 

    ipcon.connect(HOST, PORT) # Connect to brickd

    # Don't use device before ipcon is connected

 

    # Register temperature callback to function cb_temperature

    t.register_callback(t.CALLBACK_TEMPERATURE, cb_temperature)

 

    # Set period for temperature callback to 1s (1000ms)

    # Note: The temperature callback is only called every second

    #      if the temperature has changed since the last call!

    t.set_temperature_callback_period(1000)

 

client = mqtt.Client()

client.on_connect = on_connect

 

client.connect("vmiot01srv", 1883, 60)

 

#client.loop_start()

 

while True:

    time.sleep(2)

    client.publish("tinkerforge/bricklet/temperature/t8u/temperature", str(t.CALLBACK_TEMPERATURE))

 

 

raw_input()

ipcon.disconnect()

[photron]

Du registrierst hier die cb_temperature Funktion für den Temperatur Callback:

 

# Register temperature callback to function cb_temperature
t.register_callback(t.CALLBACK_TEMPERATURE, cb_temperature)

 

Die t.CALLBACK_TEMPERATURE Konstante identifiziert den Temperatur Callback, damit register_callback weiss worum es geht.

 

Die Bindings rufen dann deine cb_temperature Funktion auf und übergeben die aktuelle Temperatur sobald das Bricklet eine Änderung der Temperatur meldet.

 

Du kannst also deinen publish() Aufruf in die cb_temperature() Funktion verlegen.