GY 521 MPU 6050

Using Arduino Sensors
1

I tried to work with the mpu6050 gyroscope/ accelerometer. I got the code from the internet but the output from the sensor all show -1. I tried to rotate the sensor in the x and y direction but the values do not change. The pins are all soldered and the power stays on.
Pin Connections
Vcc - 5V
GND - GND
SDA - A4
SCL - A5

code:
#include <MPU6050.h>

#include <Wire.h>
const int MPU = 0x68;
int16_t AcX, AcY, AcZ, GyX, GyY, GyZ, temp;
char tmp_str[7];
char* convert_int16_to_str(int16_t i){
sprintf(tmp_str, "%6d", i);
return tmp_str;
}

void setup(){
Serial.begin(9600);
Wire.begin();
Wire.beginTransmission(MPU);
Wire.write(0x6B);
Wire.write(0);
Wire.endTransmission(true);
}

void loop(){
Wire.beginTransmission(MPU);
Wire.write(0x3B);
Wire.endTransmission(false);
Wire.requestFrom(MPU,14,true);
//Accelerometer values
AcX = Wire.read()<<8|Wire.read();
AcY = Wire.read()<<8|Wire.read();
AcZ = Wire.read()<<8|Wire.read();

temp = Wire.read()<<8 | Wire.read();

//Gyroscope values
GyX = Wire.read()<<8|Wire.read();
GyY = Wire.read()<<8|Wire.read();
GyZ = Wire.read()<<8|Wire.read();

Serial.print("acX = "); Serial.print(convert_int16_to_str(AcX));
Serial.print(" |acY = "); Serial.print(convert_int16_to_str(AcY));
Serial.print(" |acZ = "); Serial.print(convert_int16_to_str(AcZ));

Serial.print("gyX = "); Serial.print(convert_int16_to_str(GyX));
Serial.print(" |gyY = "); Serial.print(convert_int16_to_str(GyY));
Serial.print(" |gyZ = "); Serial.print(convert_int16_to_str(GyZ));
Serial.print("\n");

delay(100);
}

Output:
acX = -1 |acY = -1 |acZ = -1 gyX = -1 |gyY = -1 |gyZ = -1
acX = -1 |acY = -1 |acZ = -1 gyX = -1 |gyY = -1 |gyZ = -1
acX = -1 |acY = -1 |acZ = -1 gyX = -1 |gyY = -1 |gyZ = -1

Any suggestion?

2

You may need pullup resistors on the I2C lines. If the I2C scanner program doesn't return the right addresses, then communications aren't working.

You forgot to tell us what Arduino you have. A4 & A5 may not be correct.

The code you found is not a great example to follow. The following construct is not needed, and sprintf() takes up a lot of program space:

Serial.print(convert_int16_to_str(AcX));

You can get rid of the convert_int16_to_str() and replace it by lines like this:

Serial.print(AcX);