I am really short of interrupt pins on my Arduino because I have a project that already uses a lot of Arduino pins and to read DMP data from MPU6050 you always have to use an interrupt pin. I searched A LOT in the internet and many people says it's impossible to retrieve DMP data without interrupt pin. Some people also said the only way to do that would be if I could reverse engineer the MPU6050 code (which I don't know how to do).
But today, playing with MPU6050 I could finally get all of its DMP data without the interrupt pin, you just have to connect 4 pins (VCC, GND, SCL and SDA). Upload the code below to your Arduino and see that it works!
#include "MPU6050_6Axis_MotionApps20.h"
MPU6050 mpu;
uint16_t packetSize;
uint16_t fifoCount;
uint8_t fifoBuffer[64];
Quaternion q;
VectorFloat gravity;
float ypr[3];
void setup() {
Wire.begin();
TWBR = 24;
mpu.initialize();
mpu.dmpInitialize();
mpu.setXAccelOffset(-1343);
mpu.setYAccelOffset(-1155);
mpu.setZAccelOffset(1033);
mpu.setXGyroOffset(19);
mpu.setYGyroOffset(-27);
mpu.setZGyroOffset(16);
mpu.setDMPEnabled(true);
packetSize = mpu.dmpGetFIFOPacketSize();
fifoCount = mpu.getFIFOCount();
Serial.begin(115200);
}
void loop() {
while (fifoCount < packetSize) {
fifoCount = mpu.getFIFOCount();
}
if (fifoCount == 1024) {
mpu.resetFIFO();
Serial.println(F("FIFO overflow!"));
}
else {
if (fifoCount % packetSize != 0) {
mpu.resetFIFO();
}
else {
while (fifoCount >= packetSize) {
mpu.getFIFOBytes(fifoBuffer, packetSize);
fifoCount -= packetSize;
}
mpu.dmpGetQuaternion(&q, fifoBuffer);
mpu.dmpGetGravity(&gravity, &q);
mpu.dmpGetYawPitchRoll(ypr, &q, &gravity);
Serial.print("ypr\t");
Serial.print(ypr[0] * 180 / PI);
Serial.print("\t");
Serial.print(ypr[1] * 180 / PI);
Serial.print("\t");
Serial.print(ypr[2] * 180 / PI);
Serial.println();
}
}
}
There is only one problem: Intermittently the Arduino hangs in the getFIFOBytes function for no reason. I am pretty sure it's a bug because when you call too many times getFIFOBytes for some reason the Arduino freezes.
