Tilt LED 1.0

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

In this lesson, you’ll learn how to use MPU6050 Module with the ESP32 to control the LED show.

In this setup, the number of lit LEDs will increase as the tilt angle of the MPU6050 increases.

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	ESP-WROOM-32 ESP32 ESP-32S Development Board	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

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 GPIO14 , GPIO17 , GPIO26 , GPIO25 , GPIO33 , GPIO32 , GPIO23 on the ESP32.

• MPU6050

  • SDA: Connect to GPIO21 on the ESP32.

  • SCL: Connect to GPIO22 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(ESP32 Dev module) and the correct port before clicking the Upload button.

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

MPU6050 mpu;

// Remap Arduino 7–13 LEDs to safe ESP32 GPIOs (7 LEDs total)
const int ledPins[] = {14, 27, 26, 25, 33, 32, 23};
int ledCount = sizeof(ledPins) / sizeof(ledPins[0]); // LED count

void updateLEDs(float angleX);
int  mapAngleToLEDs(float angleX);

void setup() {
  // Initialize I2C on ESP32: SDA=21, SCL=22, with fast mode 400kHz
  Wire.begin(21, 22);
  Wire.setClock(400000);

  Serial.begin(115200);
  delay(50);

  // Initialize MPU6050
  mpu.initialize();
  if (!mpu.testConnection()) {
    Serial.println("MPU6050 connection failed");
    while (1) { delay(1000); }
  }

  // Set LED pins as outputs and turn all off
  for (int i = 0; i < ledCount; i++) {
    pinMode(ledPins[i], OUTPUT);
    digitalWrite(ledPins[i], LOW);
  }

  Serial.println("ESP32 + MPU6050 tilt-to-LED ready.");
}

void loop() {
  int16_t ax, ay, az; // Raw acceleration

  // Read raw acceleration from MPU6050
  mpu.getAcceleration(&ax, &ay, &az);

  // Convert to tilt angle around X using atan2(ay, az)
  float angleX = atan2((float)ay, (float)az) * 180.0f / PI;

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

  // Debug print
  Serial.print("ax: "); Serial.print(ax);
  Serial.print("  ay: "); Serial.print(ay);
  Serial.print("  az: "); Serial.print(az);
  Serial.print("  | angleX: "); Serial.println(angleX, 1);

  delay(100);
}

// Turn on a number of LEDs based on the mapped index
void updateLEDs(float angleX) {
  // Turn all LEDs off
  for (int i = 0; i < ledCount; i++) {
    digitalWrite(ledPins[i], LOW);
  }

  // Determine how many LEDs should be on
  int ledIndex = mapAngleToLEDs(angleX);

  // Light from the first LED up to ledIndex (inclusive)
  for (int i = 0; i <= ledIndex; i++) {
    if (i >= 0 && i < ledCount) digitalWrite(ledPins[i], HIGH);
  }
}

// Map tilt angle [-90, 90] to LED index [-1 ... ledCount-1]
int mapAngleToLEDs(float angleX) {
  // Clamp angle to [-90, 90]
  angleX = constrain(angleX, -90.0f, 90.0f);

  // Use absolute angle: 0 => -1 (none), 90 => ledCount-1 (all)
  int ledIndex = map((int)abs(angleX), 0, 90, 0, ledCount - 1);

  // Exactly horizontal (0°) -> no LEDs lit
  if (angleX == 0.0f) ledIndex = -1;

  return ledIndex;
}