MPU6050数据的读取[转载+整理]

加速度库函数：
void getAcceleration(int16_t* x, int16_t* y, int16_t* z);
int16_t getAccelerationX();
int16_t getAccelerationY();
int16_t getAccelerationZ();
16位，配置时四个量程可选：±2，±4，±8，±16 g。
在dmp的例程中没有找到初始化部分，估计是采用了缺省配置。
通过观察输出值，采用的是最小量程±2g，则换算系数=2^16/4=16384 LSB/g

下面是程序，中断方式，需要把MPU的中断接到arduino数字2脚上。

// Arduino Wire library is required if I2Cdev I2CDEV_ARDUINO_WIRE implementation

// is used in I2Cdev.h

#include "Wire.h"

 

// I2Cdev and MPU6050 must be installed as libraries, or else the .cpp/.h files

// for both classes must be in the include path of your project

#include "I2Cdev.h"

 

#include "MPU6050_6Axis_MotionApps20.h"

MPU6050 mpu(0x68);

 

// MPU control/status vars

bool dmpReady = false;  // set true if DMP init was successful

uint8_t mpuIntStatus;   // holds actual interrupt status byte from MPU

uint8_t devStatus;      // return status after each device operation (0 = success, !0 = error)

uint16_t packetSize;    // expected DMP packet size (default is 42 bytes)

uint16_t fifoCount;     // count of all bytes currently in FIFO

uint8_t fifoBuffer[64]; // FIFO storage buffer

 

// orientation/motion vars

Quaternion q;           // [w, x, y, z]         quaternion container

VectorFloat gravity;    // [x, y, z]            gravity vector

float ypr[3];           // [yaw, pitch, roll]   yaw/pitch/roll container and gravity vector

 

 

// ================================================================

// ===               INTERRUPT DETECTION ROUTINE                ===

// ================================================================

 

volatile bool mpuInterrupt = false;     // indicates whether MPU interrupt pin has gone high

void dmpDataReady() {

  mpuInterrupt = true;

}

 

 

 

// ================================================================

// ===                      INITIAL SETUP                       ===

// ================================================================

 

void setup() {

  Serial.begin(115200);        // opens serial port, sets data rate to 9600 bps

 

  // join I2C bus (I2Cdev library doesn't do this automatically)

  Wire.begin();

 

  // initialize device

  Serial.println("Initializing I2C devices...");

  mpu.initialize();

 

  // verify connection

  Serial.println("Testing device connections...");

  Serial.println(mpu.testConnection() ? "MPU6050 connection successful" : "MPU6050 connection failed");

 

  delay(2);

 

  // load and configure the DMP

  Serial.println("Initializing DMP...");

  devStatus = mpu.dmpInitialize();

 

  // make sure it worked (returns 0 if so)

  if (devStatus == 0) {

    // turn on the DMP, now that it's ready

    Serial.println("Enabling DMP...");

    mpu.setDMPEnabled(true);

 

    // enable Arduino interrupt detection

    Serial.println("Enabling interrupt detection (Arduino external interrupt 0)...");

    attachInterrupt(0, dmpDataReady, RISING);

    mpuIntStatus = mpu.getIntStatus();

 

    // set our DMP Ready flag so the main loop() function knows it's okay to use it

    Serial.println("DMP ready! Waiting for first interrupt...");

    dmpReady = true;

 

    // get expected DMP packet size for later comparison

    packetSize = mpu.dmpGetFIFOPacketSize();

  } 

  else {

    // ERROR!

    // 1 = initial memory load failed

    // 2 = DMP configuration updates failed

    // (if it's going to break, usually the code will be 1)

    Serial.print("DMP Initialization failed (code ");

    Serial.print(devStatus);

    Serial.println(")");

  }

}

 

void loop()

{

  float alpha,omiga;

 

  // if programming failed, don't try to do anything

  if (!dmpReady) 

    return;

 

  // wait for MPU interrupt or extra packet(s) available

  if (!mpuInterrupt && fifoCount < packetSize) 

    return;

 

  // reset interrupt flag and get INT_STATUS byte

  mpuInterrupt = false;

  mpuIntStatus = mpu.getIntStatus();

 

  // get current FIFO count

  fifoCount = mpu.getFIFOCount();

 

  // check for overflow (this should never happen unless our code is too inefficient)

  if ((mpuIntStatus & 0x10) || fifoCount == 1024) {

    // reset so we can continue cleanly

    mpu.resetFIFO();

    Serial.println("FIFO overflow!");

 

    // otherwise, check for DMP data ready interrupt (this should happen frequently)

  } 

  else if (mpuIntStatus & 0x02) {

    // wait for correct available data length, should be a VERY short wait

    while (fifoCount < packetSize) fifoCount = mpu.getFIFOCount();

 

    // read a packet from FIFO

    mpu.getFIFOBytes(fifoBuffer, packetSize);

 

    // track FIFO count here in case there is > 1 packet available

    // (this lets us immediately read more without waiting for an interrupt)

    fifoCount -= packetSize;

 

    mpu.dmpGetQuaternion(&q, fifoBuffer);

    mpu.dmpGetGravity(&gravity, &q);

    mpu.dmpGetYawPitchRoll(ypr, &q, &gravity);  //从DMP中取出Yaw、Pitch、Roll三个轴的角度，放入数组ypr。单位：弧度

    alpha=-ypr[2] * 180/M_PI;

 

    omiga=mpu.getRotationX()/16.4;        //配置是16位表示正负2000°/s, 65536/4000

 

    Serial.print("Alpha ");

    Serial.print(alpha);

    Serial.print("\tOmiga ");

    Serial.println(omiga);

 

  }

}

****MPU6050库的安装方法*************************
1. 下载arduino编译器，目前版本为1.0.5。
2. 下载MPU6050库。进入“https://github.com/jrowberg/i2cdevlib”，点击“zip”即可。
3. 安装。将上一步下载的“I2Cdev”、“MPU6050”两个文件夹拷贝到“arduino-1.0.5\libraries”目录下。
运行arduino可以在例子中看到MPU6050。OK！