Tilt LED 2.0

Note

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Kit purchase

Looking for parts? Check out our all-in-one kits below — packed with components, beginner-friendly guides, and tons of fun.

Name	Includes ESP32 board	PURCHASE LINK
ESP32 Ultimate Starter Kit	ESP32 WROOM 32E +	BUY
Universal Maker Sensor Kit		BUY

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 ESP32 project, we recommend downloading and reviewing the basic materials first.

• 1.1 Install Arduino IDE(Important)

• 1.2 Introduce of Arduino IDE

• 1.4 Install the Arduino Nano ESP32 Board (Important)

Required Components

In this project, we need the following components:

SN	COMPONENT INTRODUCTION	QUANTITY	PURCHASE LINK
1	Arduino Nano ESP32	1
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

Common Connections:

• LED

  • Connect the LEDs cathode to a 1kΩ resistor then to the negative power bus on the breadboard, and the LEDs anode to D6 to D12 on the ESP32.

• MPU6050

  • SDA: Connect to D2 on the ESP32.

  • SCL: Connect to D3 on the ESP32.

  • 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 Nano ESP32) and the correct port before clicking the Upload button.

#include <Wire.h>
#include <MPU6050.h>

MPU6050 mpu;

// LED pins (you have verified these work)
// Pin -> LED -> Resistor -> GND (HIGH = ON)
const int ledPins[] = {12, 11, 10, 9, 8, 7, 6};
const int ledCount = sizeof(ledPins) / sizeof(ledPins[0]);

// 6 boundaries -> 7 LED regions
const float thresholds[] = {-30, -15, -5, 5, 15, 30};

// LED helpers
void ledWrite(int pin, bool on) {
  digitalWrite(pin, on ? HIGH : LOW);
}

void allLedsOff() {
  for (int i = 0; i < ledCount; i++) ledWrite(ledPins[i], false);
}

void allLedsOn() {
  for (int i = 0; i < ledCount; i++) ledWrite(ledPins[i], true);
}

// LED self-test to confirm wiring
void ledSelfTest() {
  allLedsOff();

  for (int i = 0; i < ledCount; i++) {
    ledWrite(ledPins[i], true);
    delay(200);
    ledWrite(ledPins[i], false);
  }

  allLedsOn();
  delay(400);
  allLedsOff();
  delay(200);
}

// Map angle to LED index
int getLEDIndex(float angleX) {
  const int n = sizeof(thresholds) / sizeof(thresholds[0]);
  for (int i = 0; i < n; i++) {
    if (angleX < thresholds[i]) return i;
  }
  return ledCount - 1;
}

void updateLEDs(float angleX) {
  allLedsOff();
  int idx = getLEDIndex(angleX);
  if (idx >= 0 && idx < ledCount) {
    ledWrite(ledPins[idx], true);
  }
}

void setup() {
  Serial.begin(115200);
  delay(200);

  // LED setup
  for (int i = 0; i < ledCount; i++) {
    pinMode(ledPins[i], OUTPUT);
    ledWrite(ledPins[i], false);
  }

  Serial.println("LED self-test start...");
  ledSelfTest();
  Serial.println("LED self-test done.");

  // ---- I2C init (IMPORTANT CHANGE) ----
  // MPU6050 SDA -> D2
  // MPU6050 SCL -> D3
  Wire.begin(D2, D3);

  // MPU6050 init
  Serial.println("Init MPU6050...");
  mpu.initialize();

  if (!mpu.testConnection()) {
    Serial.println("MPU6050 connection failed. Blinking all LEDs.");
    while (true) {
      allLedsOn();
      delay(300);
      allLedsOff();
      delay(300);
    }
  }

  Serial.println("MPU6050 connected.");
}

void loop() {
  int16_t ax, ay, az;
  mpu.getAcceleration(&ax, &ay, &az);

  // Calculate tilt angle around X axis
  float angleX = atan2((float)ay, (float)az) * 180.0f / PI;

  Serial.print("angleX=");
  Serial.println(angleX);

  updateLEDs(angleX);
  delay(100);
}