Multiple sensor fusion in Arduino - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of fused sensor data averaging

Given two sensors providing integer readings, what is the output of the fused average printed by the Arduino code below?

Arduino

int sensor1 = 30;
int sensor2 = 50;
int fusedValue = (sensor1 + sensor2) / 2;
void setup() {
  Serial.begin(9600);
  Serial.println(fusedValue);
}
void loop() {}

A 50

B 80

C 30

D 40

💡 Hint

Think about how averaging two numbers works.

The code adds sensor1 and sensor2 (30 + 50 = 80) and divides by 2, resulting in 40.

❓ Predict Output

intermediate

Output of weighted sensor fusion

What value does the Arduino print when fusing two sensor readings with weights 0.7 and 0.3 respectively?

Arduino

float sensor1 = 20.0;
float sensor2 = 40.0;
float fusedValue = sensor1 * 0.7 + sensor2 * 0.3;
void setup() {
  Serial.begin(9600);
  Serial.println(fusedValue);
}
void loop() {}

A 26.0

B 30.0

C 28.0

D 32.0

💡 Hint

Multiply each sensor by its weight and add the results.

20.0 * 0.7 = 14.0, 40.0 * 0.3 = 12.0, 14.0 + 12.0 = 26.0.

🔧 Debug

advanced

Identify the error in sensor fusion code

What value does the following Arduino code print?

Arduino

int sensor1 = 10;
int sensor2 = 20;
int fusedValue = sensor1 + sensor2 / 2;
void setup() {
  Serial.begin(9600);
  Serial.println(fusedValue);
}
void loop() {}

A Prints 15

B Prints 30

C Prints 20

D Prints 25

💡 Hint

Remember operator precedence in arithmetic expressions.

Division happens before addition, so sensor2/2 = 10, then add sensor1 (10 + 10 = 20).

❓ Predict Output

advanced

Output of sensor fusion with conditional logic

What is the output of the Arduino code that fuses two sensor values but uses a condition to select the higher value?

Arduino

int sensor1 = 45;
int sensor2 = 55;
int fusedValue;
void setup() {
  Serial.begin(9600);
  if(sensor1 > sensor2) {
    fusedValue = sensor1;
  } else {
    fusedValue = sensor2;
  }
  Serial.println(fusedValue);
}
void loop() {}

A 55

B 45

C 100

D 0

💡 Hint

Check which sensor value is bigger.

Since 55 is greater than 45, fusedValue is set to 55.

🧠 Conceptual

expert

Number of fused data points after combining three sensors

If you fuse data from three sensors each providing 5 readings, how many total fused data points do you get if you combine readings pairwise and then fuse those results?

A 25

B 5

C 15

D 10

💡 Hint

Think about how many readings are combined at each step and if the number changes.

Pairwise fusion combines readings at the same index, so total fused points remain 5.