File content as of revision 7:33a74adff0ff:

#include "mbed.h"
#include "MPU6050_6Axis_MotionApps20.h"
#include "debug.h"

// MPU
MPU6050 mpu;
InterruptIn dataReady(P0_15);

// 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
VectorInt16 aa;         // [x, y, z]            accel sensor measurements
VectorInt16 aaReal;     // [x, y, z]            gravity-free accel sensor measurements
VectorInt16 aaWorld;    // [x, y, z]            world-frame accel sensor measurements
VectorFloat gravity;    // [x, y, z]            gravity vector
float euler[3];         // [psi, theta, phi]    Euler angle container
float ypr[3];           // [yaw, pitch, roll]   yaw/pitch/roll container and gravity vector

volatile bool mpuInterrupt = false;
void dataReadyISR() {
    mpuInterrupt = true;
}

/* Returns a pointer to an array containing the most recent data, otherwise NULL.  Requires the mpu to be initialized. */
void receive_data()
{
    static uint32_t n_overflows = 0;
//    while (true) {
    //if (!dmpReady) break;   // do nothing if dmp not ready
    if (!dmpReady) return;

    while (!mpuInterrupt && fifoCount < packetSize);

    // Reset interrupt
    mpuInterrupt = false;
    mpuIntStatus = mpu.getIntStatus();

    // get current FIFO count
    fifoCount = mpu.getFIFOCount();
    
//    PC_PRINTF("%d, ", fifoCount); PC_PRINTF("%x, ", mpuIntStatus);
    // check for overflow (this should never happen unless our code is too inefficient)
    if ((mpuIntStatus & 0x10) || fifoCount == 1024) {
        PC_PRINTLN("**** FIFO OVERFLOW ****");
        n_overflows++;
        // reset so we can continue cleanly
        mpu.resetFIFO();
        // otherwise, check for DMP data ready interrupt (this should happen frequently)
    } else if (mpuIntStatus & 0x02) {
        // Wait for a full packet - should be very short wait
        while (fifoCount < packetSize) fifoCount = mpu.getFIFOCount();

        // read a packet from FIFO
        mpu.getFIFOBytes(fifoBuffer, packetSize);
        fifoCount -= packetSize;

        // Get acceleration data
        mpu.dmpGetAccel(&aa, fifoBuffer);
//            mpu.dmpGetQuaternion(&q, fifoBuffer);
//            mpu.dmpGetGravity(&gravity, &q);
//            mpu.dmpGetLinearAccel(&aaReal, &aa, &gravity);
//            mpu.dmpGetLinearAccelInWorld(&aaWorld, &aaReal, &q);

        PC_PRINTF("%d, ", aa.x);
        PC_PRINTF("%d, ", aa.y);
        PC_PRINTLNF("%d", aa.z);
//            OLED_SETCURS(0, 10); OLED_PRINTF("%d, ", aaWorld.x); OLED_PRINTF("%d, ", aaWorld.y); OLED_PRINTLNF("%d", aaWorld.z);

//            fprintf(logFile, "%u,%d,%d,%d,%f,%f,%f,%f,%u\n", captureTime.read_ms(), aa.x, aa.y, aa.z, q.x, q.y, q.z, q.w, n_overflows);
//        }
    }
}

void receive_init() {
    PC_PRINTLN("Initializing MPU");
    mpu.initialize();
    devStatus = mpu.dmpInitialize();
    
    if (devStatus == 0) {
        mpu.setDMPEnabled(true);
        packetSize = mpu.dmpGetFIFOPacketSize();
        
        PC_PRINTLN("DMP Initialized successfully!");
        dmpReady = true;
        dataReady.rise(dataReadyISR);
    } else { // ERROR
        PC_PRINTLNF("Error initializing MPU (code %d)", devStatus);
        DIE(DMP_ERROR_RATE);
    }
}