Last Will and Testament (LWT) in IOT Protocols - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to set the Last Will and Testament (LWT) topic in an MQTT client.

IOT Protocols

client.will_set(topic=[1], payload="Offline", qos=1, retain=False)

Drag options to blanks, or click blank then click option'

A"home/temperature"

B"home/status"

C"home/light"

D"home/command"

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing a sensor data topic instead of a status topic.

The LWT topic is usually a status topic like "home/status" to notify others if the client disconnects unexpectedly.

2fill in blank

medium

Complete the code to set the LWT payload message indicating the client is offline.

IOT Protocols

client.will_set(topic="home/status", payload=[1], qos=1, retain=False)

Drag options to blanks, or click blank then click option'

A"Offline"

B"Online"

C"Connected"

D"Active"

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'Online' or 'Connected' which indicate the client is active.

The LWT payload should indicate the client is offline when it disconnects unexpectedly.

3fill in blank

hard

Fix the error in the code to correctly set the LWT with retain flag.

IOT Protocols

client.will_set(topic="home/status", payload="Offline", qos=1, retain=[1])

Drag options to blanks, or click blank then click option'

A1

B"True"

CFalse

DTrue

Attempts:

3 left

💡 Hint

Common Mistakes

Using string "True" instead of boolean True.

Using integer 1 instead of boolean.

The retain flag must be a boolean True or False, not a string or integer.

4fill in blank

hard

Fill both blanks to create a dictionary for LWT settings with topic and payload.

IOT Protocols

lwt_settings = {"topic": [1], "payload": [2]

Drag options to blanks, or click blank then click option'

A"home/status"

B"Offline"

C"home/command"

D"Online"

Attempts:

3 left

💡 Hint

Common Mistakes

Swapping topic and payload values.

Using wrong topic or payload strings.

The LWT dictionary should have the topic as "home/status" and payload as "Offline" to notify disconnection.

5fill in blank

hard

Fill all three blanks to set LWT with topic, payload, and QoS level.

IOT Protocols

client.will_set(topic=[1], payload=[2], qos=[3], retain=True)

Drag options to blanks, or click blank then click option'

A"home/status"

B"Offline"

C1

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Using QoS 0 which is less reliable.

Using wrong topic or payload.

The LWT should use the status topic, offline payload, and QoS level 1 for reliable delivery.