[Solved] Identify the error in this MQTT subscription code snippet for Raspberry Pi: def on_message(client, userdata, message): print(message.payload) client.on_message = on_message client.... | Raspberry Pi

Raspberry Pi - MQTT for IoT

Identify the error in this MQTT subscription code snippet for Raspberry Pi:

def on_message(client, userdata, message):
    print(message.payload)

client.on_message = on_message
client.subscribe("home/lights/control")
client.loop_start()

AIncorrect callback function name

BMissing client.connect() before subscribing

CUsing loop_start() instead of loop_forever()

DNo error, code is correct

Step-by-Step Solution

Solution:

Step 1: Check connection setup
Before subscribing, the client must connect to the MQTT broker.
Step 2: Identify missing connect call
The code lacks client.connect() call, so subscription won't work.
Final Answer:
Missing client.connect() before subscribing -> Option B
Quick Check:
Must connect before subscribe [OK]

Quick Trick: Always connect client before subscribing [OK]

Common Mistakes:

MISTAKES

Skipping client.connect() call
Confusing callback function names
Thinking loop_start() is wrong here

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More Raspberry Pi Quizzes

Identify the error in this MQTT subscription code snippet for Raspberry Pi:

Step 1: Check connection setup

Step 2: Identify missing connect call

Final Answer:

Quick Check:

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