Arduino Project

Tilt LED 2.0

Course Introduction

This project controls an array of LEDs based on the tilt angle detected by an MPU6050 sensor.

The LEDs illuminate in response to X-axis tilt, visually indicating the board’s orientation.

Tilt angles are continuously calculated from acceleration data provided by the MPU6050, and corresponding LEDs activate according to predefined angle thresholds.

Note

If this is your first time working with an Arduino project, we recommend downloading and reviewing the basic materials first.

1.1 Install Arduino IDE(Important)
1.2 Introduction of Arduino IDE

Required Components

In this project, we need the following components:

SN

COMPONENT INTRODUCTION

QUANTITY

PURCHASE LINK

1

Arduino UNO R4

1

BUY

2

USB Type-C cable

1

×

3

Breadboard

1

BUY

4

Wires

Several

BUY

5

1kΩ resistor

Several

BUY

6

LED

Several

BUY

7

MPU6050 Module

1

BUY

Wiring

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Common Connections:

LED
Connect the LEDs anode to a 1kΩ resistor then to the negative power bus on the breadboard, and the LEDs cathode to 8 to 13 on the Arduino.

MPU6050
SDA:Connect to SDA on the Arduino.
SCL: Connect to SCL on the Arduino.
GND: Connect to breadboard’s negative power bus.
VCC: Connect to breadboard’s red power bus.

Writing the Code

Note
You can copy this code into Arduino IDE.
To install the library, use the Arduino Library Manager and search for MPU6050 and install it.
Don’t forget to select the board(Arduino UNO R3) and the correct port before clicking the Upload button.


#include 
#include 

MPU6050 mpu;

// LED pins 7-13 on Arduino
const int ledPins[] = {13, 12, 11, 10, 9, 8, 7};
int ledCount = sizeof(ledPins) / sizeof(ledPins[0]); // LED count

// Tilt angle thresholds for LEDs
const float thresholds[] = {-30, -15, -5, 5, 15, 30};

void setup() {
  Wire.begin(); // Init I2C
  Serial.begin(9600); // Init serial

  // Init MPU6050
  mpu.initialize();
  if (!mpu.testConnection()) {
    Serial.println("MPU6050 connection failed");
    while (1); // Stop if MPU6050 fails
  }

  // Set LED pins as output
  for (int i = 0; i < ledCount; i++) {
    pinMode(ledPins[i], OUTPUT);
  }
}

void loop() {
  int16_t ax, ay, az; // Acceleration data

  // Get MPU6050 acceleration
  mpu.getAcceleration(&ax, &ay, &az);

  // Calculate tilt angle (X-axis)
  float angleX = atan2(ay, az) * 180 / PI;

  // Update LEDs based on angle
  updateLEDs(angleX);

  delay(100); // Stabilize output
}

// Update LEDs based on angle
void updateLEDs(float angleX) {
  // Turn off all LEDs
  for (int i = 0; i < ledCount; i++) {
    digitalWrite(ledPins[i], LOW);
  }

  // Get the LED index for the angle
  int ledIndex = getLEDIndex(angleX);

  // Turn on the correct LED
  if (ledIndex >= 0 && ledIndex < ledCount) {
    digitalWrite(ledPins[ledIndex], HIGH);
  }
}

// Determine the LED index for the angle
int getLEDIndex(float angleX) {
  // Find the matching LED
  for (int i = 0; i < ledCount - 1; i++) {
    if (angleX < thresholds[i]) {
      return i; // Return matching LED index
    }
  }
  return ledCount - 1; // Return last LED if angle exceeds thresholds
}