GY-45 MMA8452 3-Axis Accelerator Module

GY-45 Module          →    Arduino Uno
─────────────────────────────────────────
VCC                   →    5V
GND                   →    GND
SCL                   →    A5 (SCL)
SDA                   →    A4 (SDA)
SA0                   →    GND (for address 0x1C)
INT1 (optional)       →    D2 (or any digital pin)

/*
  GY-45 MMA8452 Accelerometer Basic Read Example
*/

#include <Wire.h>
#include <Adafruit_MMA8452.h>

Adafruit_MMA8452 mma = Adafruit_MMA8452();

void setup() {
  Serial.begin(9600);
  
  if (!mma.begin()) {
    Serial.println("Could not find MMA8452 sensor. Check wiring!");
    while (1);
  }
  
  Serial.println("GY-45 MMA8452 Sensor Ready");
  
  // Set measurement range (±2g, ±4g, ±8g)
  mma.setRange(MMA8452_RANGE_2_G);
  
  Serial.print("Range set to: ");
  Serial.print(2 << mma.getRange());
  Serial.println("g");
}

void loop() {
  // Read accelerometer data
  mma.read();
  
  Serial.print("X: ");
  Serial.print(mma.x);
  Serial.print("  Y: ");
  Serial.print(mma.y);
  Serial.print("  Z: ");
  Serial.print(mma.z);
  Serial.println();
  
  // Convert to g-force (raw data / 4096 for ±2g range)
  float xg = mma.x / 4096.0;
  float yg = mma.y / 4096.0;
  float zg = mma.z / 4096.0;
  
  Serial.print("Force (g): ");
  Serial.print(xg);
  Serial.print(", ");
  Serial.print(yg);
  Serial.print(", ");
  Serial.println(zg);
  
  // Calculate tilt angles
  float pitch = atan2(-xg, sqrt(yg * yg + zg * zg)) * 180 / PI;
  float roll = atan2(yg, zg) * 180 / PI;
  
  Serial.print("Pitch: ");
  Serial.print(pitch);
  Serial.print("°, Roll: ");
  Serial.println(roll);
  Serial.println();
  
  delay(500);
}

/*
  MMA8452 Motion Detection Example
*/

#include <Wire.h>
#include <Adafruit_MMA8452.h>

Adafruit_MMA8452 mma = Adafruit_MMA8452();

void setup() {
  Serial.begin(9600);
  
  if (!mma.begin()) {
    Serial.println("Sensor not found");
    while (1);
  }
  
  // Configure for freefall detection
  mma.writeRegister(MMA8452_FF_MT_CFG, 0x38);  // Enable freefall on all axes
  mma.writeRegister(MMA8452_FF_MT_THS, 0x0A);  // Set threshold
  mma.writeRegister(MMA8452_FF_MT_COUNT, 0x05); // Set debounce count
  
  // Enable interrupt on INT1 pin
  mma.writeRegister(MMA8452_CTRL_REG4, 0x04);   // Enable freefall interrupt
  mma.writeRegister(MMA8452_CTRL_REG5, 0x01);   // Route to INT1 pin
}

void loop() {
  if (mma.readTap() & 0x04) {  // Freefall detected
    Serial.println("Freefall detected!");
  }
  delay(100);
}