I am setting up to receive MQTT data from a subscribed topic and I want to save the data in a text file.
I have added the code to save the variable to a text file. However this doesn't work as it gives me just the variable and not the value of it i.e. doesn't give me the values of "on_message". Can someone please help me?
Thanks
My code is as follows:
import paho.mqtt.client as mqttClient
import time
def on_connect(client, userdata, flags, rc):
if rc == 0:
print("Connected to broker")
global Connected #Use global variable
Connected = True #Signal connection
else:
print("Connection failed")
def on_message(client, userdata, message):
print "Message received: " + message.payload
Connected = False #global variable for the state of the connection
broker_address= "192.168.0.6" #Broker address
port = 1883 #Broker port
user = "me" #Connection username
password = "abcdef" #Connection password
client = mqttClient.Client("Python") #create new instance
client.username_pw_set(user, password=password) #set username and password
client.on_connect= on_connect #attach function to callback
client.on_message= on_message #attach function to callback
f = open('/home/pi/test.txt','w')
f.write('on_message')
f.close()
client.connect(broker_address, port=port) #connect to broker
client.loop_start() #start the loop
while Connected != True: #Wait for connection
time.sleep(0.1)
client.subscribe("home/OpenMQTTGateway/433toMQTT")
try:
while True:
time.sleep(1)
except KeyboardInterrupt:
print "exiting"
client.disconnect()
client.loop_stop()
I have tried other attempts but have failed. I am fairly new to python and still learning.
You should append data to file in on_message call back and obviously should connect then subscribe to topic
import paho.mqtt.client as mqttClient
import time
def on_connect(client, userdata, flags, rc):
if rc == 0:
print("Connected to broker")
global Connected #Use global variable
Connected = True #Signal connection
else:
print("Connection failed")
def on_message(client, userdata, message):
print "Message received: " + message.payload
with open('/home/pi/test.txt','a+') as f:
f.write("Message received: " + message.payload + "\n")
Connected = False #global variable for the state of the connection
broker_address= "192.168.0.6" #Broker address
port = 1883 #Broker port
user = "me" #Connection username
password = "abcdef" #Connection password
client = mqttClient.Client("Python") #create new instance
client.username_pw_set(user, password=password) #set username and password
client.on_connect= on_connect #attach function to callback
client.on_message= on_message #attach function to callback
client.connect(broker_address,port,60) #connect
client.subscribe("some/topic") #subscribe
client.loop_forever() #then keep listening forever
Now if you publish message on "some/topic" your code shall append data to the file