mpu.getFIFOBytes crashes

[carlesgel]

I am writing a small abstraction class for the MPU6050 to be used with a scheduler.

I call the update function at 100hr and it seems to work for a while (fro 20sec to 4min) but eventually crashes. I think I have located the point of failure but I cannot understand what is the problem.

 

this is the update function: (it is based on the DMP example but i got rid of the interrupts)

 

void update() {

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

if (!dmpReady) return;

 

Serial.print(F("a")); // +

 

// get current FIFO count

fifoCount = mpu.getFIFOCount();

Serial.print(F("b"));

 

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

if (fifoCount == 1024) {

// reset so we can continue cleanly

mpu.resetFIFO();

overflowCount += 1;

} else if (fifoCount == 0) {

pullEmptyMissCount += 1;

} else if (fifoCount < packetSize) {

pullMissCount += 1;

} else { // in this case the fifo has one or more packets

Serial.print(F("c"));

 

// if there are more than on packet, will read all of them and keep the newest

lastBuferReadCount = 0;

while (fifoCount >= packetSize)

{

// read a packet from FIFO

Serial.print(F("d")); // ++

mpu.getFIFOBytes(fifoBuffer, packetSize);

lastBuferReadCount += 1;

 

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

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

fifoCount -= packetSize;

//fifoCount -= mpu.getFIFOCount(); // It is slower than subtracting the packet size, but in case new data comes in it will allow to read it.

}

Serial.print(F("e"));

// Update Quaternion, Euler angles and Yay Pich Roll angles

mpu.dmpGetQuaternion(&q, fifoBuffer);

mpu.dmpGetGravity(&gravity, &q);

mpu.dmpGetYawPitchRoll(ypr, &q, &gravity);

}

float* ypr = get_ypr();

int ofc = overflowCount;

int pm = pullMissCount;

int pem = pullEmptyMissCount;

int rc = lastBuferReadCount;

cout <<"- "<<ypr[0]<<" - "<<ypr[1]<<" - "<<ypr[2]<<" - "<<" - overflow: "<<ofc<<" - empty miss: "<<pem<<" - miss: "<<pm<<" - readCount: "<<rc<< endl;

 

Serial.println(F(""));

}