Why power matters for battery projects in Arduino - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to set the LED pin as output.

Arduino

void setup() {
  pinMode([1], OUTPUT);
}

void loop() {
  // LED control code
}

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

A7

B13

CA0

D12

Attempts:

3 left

💡 Hint

Common Mistakes

Using analog pins like A0 instead of digital pins.

Choosing pins not connected to the LED.

The built-in LED on most Arduino boards is connected to pin 13, so we set pin 13 as output.

2fill in blank

medium

Complete the code to turn the LED on.

Arduino

void loop() {
  digitalWrite(13, [1]);
  delay(1000);
  digitalWrite(13, LOW);
  delay(1000);
}

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

ALOW

BINPUT

CHIGH

DOUTPUT

Attempts:

3 left

💡 Hint

Common Mistakes

Using LOW instead of HIGH to turn on the LED.

Confusing pin modes with output values.

To turn the LED on, we set the pin to HIGH.

3fill in blank

hard

Fix the error in the code to correctly read battery voltage on analog pin A0.

Arduino

int sensorValue = analogRead([1]);
float voltage = sensorValue * (5.0 / 1023.0);

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

A13

BA0

CA1

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'A0' as a string instead of 0.

Using digital pin numbers for analogRead.

analogRead expects the analog pin number as an integer, so A0 is pin 0.

4fill in blank

hard

Fill both blanks to calculate battery voltage with a voltage divider.

Arduino

float batteryVoltage = sensorValue * ([1] / 1023.0) * ([2] + 10.0) / 10.0;

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

A5.0

B3.3

C20.0

D15.0

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong reference voltage.

Incorrect resistor values in formula.

The Arduino uses 5V reference, and the voltage divider resistors are 10k and 20k ohms, so we multiply by (20+10)/10.

5fill in blank

hard

Fill all three blanks to print battery voltage with 2 decimal places.

Arduino

Serial.print("Battery Voltage: ");
Serial.print([1], [2]);
Serial.println([3]);

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

AbatteryVoltage

B2

C" V"

Dvoltage

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong variable name.

Forgetting to print the unit.

We print the variable batteryVoltage with 2 decimals, then print the unit " V" on a new line.