WiFi power consumption challenges in IOT Protocols - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to set the WiFi module to low power mode.

IOT Protocols

wifi.setPowerMode([1])

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

A"MEDIUM"

B"HIGH"

C"LOW"

D"OFF"

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing HIGH power mode increases consumption.

Using OFF disables WiFi completely.

Setting the power mode to "LOW" reduces WiFi power consumption.

2fill in blank

medium

Complete the code to enable WiFi sleep mode for power saving.

IOT Protocols

wifi.[1]Sleep(true)

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

Aenable

Bset

Cdisable

Dstart

Attempts:

3 left

💡 Hint

Common Mistakes

Using disableSleep(true) turns sleep mode off.

Using startSleep(true) is not a valid method.

Enabling sleep mode allows the WiFi module to save power when idle.

3fill in blank

hard

Fix the error in the code to increase WiFi beacon interval for power saving.

IOT Protocols

wifi.setBeaconInterval([1])

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

A0

B10

C100

D5000

Attempts:

3 left

💡 Hint

Common Mistakes

Using 0 disables beacons and may cause connection issues.

Using 10 or 100 ms is too frequent and wastes power.

Increasing the beacon interval to 5000 ms reduces how often WiFi wakes up, saving power.

4fill in blank

hard

Fill both blanks to create a dictionary that maps WiFi states to power consumption levels.

IOT Protocols

power_levels = {"CONNECTED": [1], "DISCONNECTED": [2]

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

A"HIGH"

B"LOW"

C"MEDIUM"

D"OFF"

Attempts:

3 left

💡 Hint

Common Mistakes

Assigning LOW power to connected state is incorrect.

Using OFF for connected state disables WiFi.

When connected, WiFi uses HIGH power; when disconnected, it uses LOW power.

5fill in blank

hard

Fill all three blanks to create a dictionary comprehension filtering WiFi networks with signal strength above threshold.

IOT Protocols

strong_networks = {net: [1] for net, [2] in networks.items() if [3] > -70}

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

Asignal_strength

Dnet

Attempts:

3 left

💡 Hint

Common Mistakes

Using net as value instead of signal strength.

Using net in the condition instead of signal strength.

The dictionary maps network names (net) to their signal strength if signal_strength is greater than -70 dBm.

Practice

1. What is a common challenge when using WiFi in battery-powered IoT devices?

easy

A. High power consumption leading to faster battery drain

B. WiFi signals never drop, causing no connection issues

C. WiFi uses no power when idle

D. WiFi automatically charges the battery

Solution

1. Step 1: Understand WiFi power use

   WiFi radios consume significant power, especially when active or transmitting data.

2. Step 2: Relate to battery life

   High power use means batteries drain faster, which is a key challenge for IoT devices.

3. Final Answer:

   High power consumption leading to faster battery drain -> Option A

4. Quick Check:

   WiFi power use = battery drain [OK]

Hint: Remember WiFi uses power even when idle [OK]

Common Mistakes:

• Thinking WiFi never drains battery
• Assuming WiFi charges devices
• Believing WiFi uses zero power when idle

2. Which of the following is the correct way to enable WiFi power-saving mode in a device configuration?

easy

A. wifi.enablePowerSave = off;

B. wifi.powerSave = disable;

C. wifi.powerSaveMode = 0;

D. wifi.setPowerSave(true);

Solution

1. Step 1: Identify correct syntax for enabling power save

   The method wifi.setPowerSave(true); correctly enables power-saving mode.

2. Step 2: Check other options for syntax errors

   The other options use incorrect syntax or disable power saving.

3. Final Answer:

   wifi.setPowerSave(true); -> Option D

4. Quick Check:

   Correct method call enables power save [OK]

Hint: Look for method calls with true/false to enable features [OK]

Common Mistakes:

• Using assignment with wrong values
• Confusing enable/disable keywords
• Incorrect syntax for method calls

3. Consider this pseudocode for a WiFi IoT device:

if device.isIdle():
    wifi.enterPowerSave()
else:
    wifi.transmitData()

What is the expected effect on power consumption when the device is idle?

medium

A. Power consumption decreases by entering power save mode

B. Device shuts down WiFi completely

C. Power consumption stays the same regardless of state

D. Power consumption increases due to constant transmission

Solution

1. Step 1: Analyze idle condition

   When device.isIdle() is true, the device calls wifi.enterPowerSave().

2. Step 2: Understand power save effect

   Entering power save mode reduces power consumption by lowering WiFi activity.

3. Final Answer:

   Power consumption decreases by entering power save mode -> Option A

4. Quick Check:

   Idle + power save = less power used [OK]

Hint: Idle devices save power by entering power save mode [OK]

Common Mistakes:

• Assuming power use increases when idle
• Thinking power save disables WiFi fully
• Believing power consumption is constant

4. A developer wrote this code to reduce WiFi power use:

if device.isIdle()
    wifi.enterPowerSave()
else
    wifi.transmitData()

What is the main error in this code?

medium

A. No else block present

B. Using wrong method name for power save

C. Missing colon after if condition

D. WiFi cannot enter power save mode

Solution

1. Step 1: Check syntax of if statement

   The if statement lacks a colon at the end, which is required in Python-like syntax.

2. Step 2: Verify other parts

   Method names and else block are correct; WiFi can enter power save mode.

3. Final Answer:

   Missing colon after if condition -> Option C

4. Quick Check:

   Python if needs colon [OK]

Hint: Look for missing colons in if statements [OK]

Common Mistakes:

• Ignoring syntax errors
• Assuming method names are wrong
• Thinking else block is missing

5. You want to design an IoT sensor that uses WiFi but lasts weeks on a small battery. Which strategy best balances power use and communication?

hard

A. Keep WiFi always on for instant data sending

B. Use WiFi power-saving mode and batch data transmissions

C. Turn off WiFi completely and never send data

D. Send data continuously without power-saving

Solution

1. Step 1: Consider power-saving modes

   Using WiFi power-saving mode reduces energy use during idle times.

2. Step 2: Batch data transmissions

   Sending data in batches reduces how often WiFi is active, saving power.

3. Step 3: Balance communication and battery life

   This approach keeps communication effective while extending battery life.

4. Final Answer:

   Use WiFi power-saving mode and batch data transmissions -> Option B

5. Quick Check:

   Power save + batch send = longer battery [OK]

Hint: Batch sends + power save extend battery life [OK]

Common Mistakes:

• Keeping WiFi always on wastes battery
• Turning off WiFi stops communication
• Sending data continuously drains battery fast