Mpu6050 Connection failed - arduino

Question

I am using mpu6050 for my project but it shows following error -
Testing device connections...
MPU6050 connection failed
this error is showed only when iI am trying to use object of MPU6050
but when I don't use instance of MPU6050 and use Wire library instead (like follow) it works -
Wire.begin(); // Initialize communication
Wire.beginTransmission(MPU); // Start communication with MPU6050 // MPU=0x68
Wire.write(0x6B); // Talk to the register 6B
Wire.write(0x00); // Make reset - place a 0 into the 6B register
Wire.endTransmission(true); //end the transmission
but I want to use this code -
mpu.initialize(); //start MPU
Serial.println(F("Testing device connections...")); //debugging serial statement
Serial.println(mpu.testConnection() ? F("MPU6050 connection successful") : F("MPU6050 connection failed"));
// supply your own gyro offsets here, scaled for min sensitivity
mpu.setXGyroOffset(0);
mpu.setYGyroOffset(0);
mpu.setZGyroOffset(0);
mpu.setZAccelOffset(1688);
please help me

Answer 1

I had the same problem.
The problem comes from those lines in the MPU6050.cpp file. You can find it in your sketchbook folder.
To do so: Open the Arduino IDE then File > Preferences > Sketchbook location.
//I2Cdev device library code is placed under the MIT license
//Copyright (c) 2012 Jeff Rowberg
/** Verify the I2C connection.
* Make sure the device is connected and responds as expected.
* #return True if connection is valid, false otherwise
*/
bool MPU6050::testConnection() {
return getDeviceID() == 0x34;
}
This is the getDeviceId function
//I2Cdev device library code is placed under the MIT license
//Copyright (c) 2012 Jeff Rowberg
/** Get Device ID.
* This register is used to verify the identity of the device (0b110100, 0x34).
* #return Device ID (6 bits only! should be 0x34)
* #see MPU6050_RA_WHO_AM_I
* #see MPU6050_WHO_AM_I_BIT
* #see MPU6050_WHO_AM_I_LENGTH
*/
uint8_t MPU6050::getDeviceID() {
I2Cdev::readBits(devAddr, MPU6050_RA_WHO_AM_I, MPU6050_WHO_AM_I_BIT, MPU6050_WHO_AM_I_LENGTH, buffer);
return buffer[0];
}
I just modified the testConnection function to return true, and it worked for me.
//I2Cdev device library code is placed under the MIT license
//Copyright (c) 2012 Jeff Rowberg
bool MPU6050::testConnection() {
return true;
}

Answer 2

The problem is that the device identifier is not 0x34 (in my case it is 0x39).
In order not to "cheat" I made the following change:
Comment out this line:
Serial.println(accelgyro.testConnection() ? "MPU6050 connection successful" : "MPU6050 connection failed");
And inserted these lines:
Serial.print("DeviceID: ");
Serial.println(accelgyro.getDeviceID());
So the program will write the device identifier instead of giving a response that it didn't find device 0x34.