Sending sensor data to computer in Arduino - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to start serial communication at 9600 baud.

Arduino

void setup() {
  Serial.[1](9600);
}

void loop() {
  // sensor reading code
}

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

Abegin

Bopen

Cstart

Dinit

Attempts:

3 left

💡 Hint

Common Mistakes

Using Serial.start() instead of Serial.begin()

Forgetting to start serial communication

The Serial.begin(9600); command starts serial communication at 9600 baud rate.

2fill in blank

medium

Complete the code to read an analog sensor value from pin A0.

Arduino

int sensorValue = [1](A0);

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

AanalogRead

BdigitalRead

CreadAnalog

DreadDigital

Attempts:

3 left

💡 Hint

Common Mistakes

Using digitalRead() for analog pins

Using incorrect function names like readAnalog()

The analogRead(A0); function reads the analog value from pin A0.

3fill in blank

hard

Fix the error in sending the sensor value to the computer.

Arduino

Serial.[1](sensorValue);

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

Asend

BsendValue

CwriteValue

Dprint

Attempts:

3 left

💡 Hint

Common Mistakes

Using non-existent functions like send() or writeValue()

Forgetting to use Serial.print() to send data

The correct function to send data over serial is Serial.print().

4fill in blank

hard

Fill both blanks to send the sensor value followed by a new line.

Arduino

Serial.[1](sensorValue);
Serial.[2]();

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

Aprint

Bprintln

Cwrite

Dsend

Attempts:

3 left

💡 Hint

Common Mistakes

Using println() for both lines causing double new lines

Using write() or send() which are incorrect here

Use Serial.print() to send the value and Serial.println() to add a new line.

5fill in blank

hard

Fill all three blanks to read sensor data, send it, and add a delay.

Arduino

int sensorValue = [1](A1);
Serial.[2](sensorValue);
delay([3]);

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

AanalogRead

Bprint

C1000

DdigitalRead

Attempts:

3 left

💡 Hint

Common Mistakes

Using digitalRead for analog sensor

Forgetting delay or using wrong delay value

Using Serial.println instead of print if not desired

Read analog value with analogRead(), send it with Serial.print(), and pause for 1000 milliseconds with delay(1000);.

Practice

1. What is the purpose of Serial.begin(9600); in an Arduino sketch when sending sensor data to a computer?

easy

A. It reads the sensor value from analog pin 0.

B. It stops the serial communication.

C. It sends data to the sensor.

D. It starts serial communication at 9600 bits per second.

Solution

1. Step 1: Understand Serial.begin()

   Serial.begin(9600); initializes serial communication at 9600 bits per second speed.

2. Step 2: Identify its role in communication

   This function sets up the Arduino to send and receive data through the serial port to the computer.

3. Final Answer:

   It starts serial communication at 9600 bits per second. -> Option D

4. Quick Check:

   Serial.begin() = start communication [OK]

Hint: Serial.begin() always starts communication speed [OK]

Common Mistakes:

• Confusing Serial.begin() with reading sensor data
• Thinking Serial.begin() sends data
• Assuming Serial.begin() stops communication

2. Which of the following is the correct syntax to read an analog sensor connected to pin A0 and store its value in a variable named sensorValue?

easy

A. sensorValue = digitalRead(A0);

B. sensorValue = analogRead(A0);

C. sensorValue = analogWrite(A0);

D. sensorValue = Serial.read(A0);

Solution

1. Step 1: Identify the function to read analog input

   The function analogRead(pin) reads the voltage on an analog pin and returns a value between 0 and 1023.

2. Step 2: Match the correct syntax

   Using sensorValue = analogRead(A0); correctly reads the sensor on pin A0 and stores it.

3. Final Answer:

   sensorValue = analogRead(A0); -> Option B

4. Quick Check:

   analogRead() reads analog sensor [OK]

Hint: Use analogRead() for analog sensors, not digitalRead() [OK]

Common Mistakes:

• Using digitalRead() for analog sensors
• Confusing analogRead() with analogWrite()
• Trying to read sensor with Serial.read()

3. What will be the output on the serial monitor when running this Arduino code snippet?

void setup() {
  Serial.begin(9600);
}

void loop() {
  int sensorValue = analogRead(A0);
  Serial.println(sensorValue);
  delay(1000);
}

medium

A. No output because Serial.begin() is missing.

B. The digital value 0 or 1 printed every second.

C. The analog value from pin A0 printed every second.

D. A syntax error because delay() is not allowed.

Solution

1. Step 1: Analyze the code flow

   The code initializes serial communication, reads analog value from A0, prints it, then waits 1 second.

2. Step 2: Understand Serial.println() output

   Serial.println(sensorValue) sends the analog reading as a number to the serial monitor every 1000 ms.

3. Final Answer:

   The analog value from pin A0 printed every second. -> Option C

4. Quick Check:

   Serial.println(analogRead(A0)) = analog value output [OK]

Hint: Serial.println() prints values line by line [OK]

Common Mistakes:

• Thinking analogRead() returns digital 0 or 1
• Forgetting Serial.begin() causes no output
• Assuming delay() causes errors

4. Identify the error in this Arduino code that tries to send sensor data to the computer:

void setup() {
  Serial.begin(9600);
}

void loop() {
  int sensorValue = analogRead(10);
  Serial.print(sensorValue);
  delay(500);
}

medium

A. Using analogRead(10) instead of analogRead(A0).

B. Missing Serial.begin() in setup().

C. Using Serial.print() instead of Serial.println().

D. delay() cannot be used in loop().

Solution

1. Step 1: Check analogRead() parameter

   analogRead() expects an analog pin like A0, not just 10. Using 10 may cause unexpected behavior.

2. Step 2: Confirm other parts are correct

   Serial.begin() is present, Serial.print() works but prints without newline, delay() is allowed.

3. Final Answer:

   Using analogRead(10) instead of analogRead(A0). -> Option A

4. Quick Check:

   Use A0 for analogRead() pin [OK]

Hint: Use A0, A1... for analog pins, not just numbers [OK]

Common Mistakes:

• Using numeric 10 instead of A0 for analogRead()
• Thinking Serial.print() must be Serial.println()
• Believing delay() is disallowed in loop()

5. You want to send temperature sensor data from analog pin A1 to the computer every 2 seconds. Which code snippet correctly implements this?

hard

A. void setup() {
Serial.begin(9600);
}

void loop() {
int temp = analogRead(A1);
Serial.println(temp);
delay(2000);
}

B. void setup() {
Serial.begin(115200);
}

void loop() {
int temp = digitalRead(A1);
Serial.print(temp);
delay(2000);
}

C. void setup() {
Serial.begin(9600);
}

void loop() {
int temp = analogRead(1);
Serial.println(temp);
delay(1000);
}

D. void setup() {
Serial.begin(9600);
}

void loop() {
int temp = analogRead(A1);
Serial.print(temp);
delay(500);
}

Solution

1. Step 1: Check serial speed and pin reading

   Serial.begin(9600) is standard and analogRead(A1) correctly reads temperature sensor on pin A1.

2. Step 2: Verify output and delay timing

   Serial.println(temp) sends data with newline, delay(2000) waits 2 seconds as required.

3. Final Answer:

   Code snippet D correctly reads and sends data every 2 seconds. -> Option A

4. Quick Check:

   Use analogRead(A1), Serial.println(), delay(2000) [OK]

Hint: Use Serial.println() and delay(2000) for 2-second intervals [OK]

Common Mistakes:

• Using digitalRead() for analog sensor
• Wrong delay time for 2 seconds
• Using analogRead(1) instead of analogRead(A1)