About MinhNhat

Hi everyone, I am working with the BMX055 sensor and using I2C to communicate. The data value of the accelerometer and gyroscope is correct but the raw data from the magnetometer is quite weird.  I tried to change the direction of the BMX055 sensor in few degrees but its output raw value did not change and. However, when I rotated it in 90 degrees or more the output value of the magnetometer is changed a lot. Blue: x-axis Green: y-axis Red: z-axis This my code to read the value of the accelerometer, gyroscope, and magnetometer.   #include<Wire.h> // BMX055　加速度センサのI2Cアドレス #define Addr_Accl 0x19 // (JP1,JP2,JP3 = Openの時) // BMX055　ジャイロセンサのI2Cアドレス #define Addr_Gyro 0x69 // (JP1,JP2,JP3 = Openの時) // BMX055　磁気センサのI2Cアドレス #define Addr_Mag 0x13 // (JP1,JP2,JP3 = Openの時) // センサーの値を保存するグローバル関数 float xAccl = 0.00; float yAccl = 0.00; float zAccl = 0.00; float xGyro = 0.00; float yGyro = 0.00; float zGyro = 0.00; int xMag = 0; int yMag = 0; int zMag = 0; void setup() { // Wire(Arduino-I2C)の初期化 Wire.begin(); // デバック用シリアル通信は9600bps Serial.begin(9600); //BMX055 初期化 BMX055_Init(); delay(100); } void loop() { Serial.println("--------------------------------------"); //BMX055 加速度の読み取り BMX055_Accl(); //Serial.print("Accl= "); Serial.println(xAccl); //Serial.print(","); Serial.println(yAccl); //Serial.print(","); Serial.println(zAccl); //Serial.println(""); //BMX055 ジャイロの読み取り BMX055_Gyro(); //Serial.print("Gyro= "); Serial.println(xGyro); //Serial.print(","); Serial.println(yGyro); //Serial.print(","); Serial.println(zGyro); //Serial.println(""); //BMX055 磁気の読み取り BMX055_Mag(); //Serial.print("Mag= "); Serial.println(xMag); //Serial.print(","); Serial.println(yMag); //Serial.print(","); Serial.println(zMag); //Serial.println(""); delay(10); } //=====================================================================================// void BMX055_Init() { //------------------------------------------------------------// Wire.beginTransmission(Addr_Accl); Wire.write(0x0F); // Select PMU_Range register Wire.write(0x03); // Range = +/- 2g Wire.endTransmission(); delay(100); //------------------------------------------------------------// Wire.beginTransmission(Addr_Accl); Wire.write(0x10); // Select PMU_BW register Wire.write(0x08); // Bandwidth = 7.81 Hz Wire.endTransmission(); delay(100); //------------------------------------------------------------// Wire.beginTransmission(Addr_Accl); Wire.write(0x11); // Select PMU_LPW register Wire.write(0x00); // Normal mode, Sleep duration = 0.5ms Wire.endTransmission(); delay(100); //------------------------------------------------------------// Wire.beginTransmission(Addr_Gyro); Wire.write(0x0F); // Select Range register Wire.write(0x04); // Full scale = +/- 125 degree/s Wire.endTransmission(); delay(100); //------------------------------------------------------------// Wire.beginTransmission(Addr_Gyro); Wire.write(0x10); // Select Bandwidth register Wire.write(0x07); // ODR = 100 Hz Wire.endTransmission(); delay(100); //------------------------------------------------------------// Wire.beginTransmission(Addr_Gyro); Wire.write(0x11); // Select LPM1 register Wire.write(0x00); // Normal mode, Sleep duration = 2ms Wire.endTransmission(); delay(100); //------------------------------------------------------------// //// Addr_Mag 0x13 Wire.beginTransmission(Addr_Mag); Wire.write(0x4B); // Select Mag register Wire.write(0x83); // Soft reset Wire.endTransmission(); delay(100); //------------------------------------------------------------// Wire.beginTransmission(Addr_Mag); Wire.write(0x4B); // Select Mag register Wire.write(0x01); // Soft reset Wire.endTransmission(); delay(100); //------------------------------------------------------------// Wire.beginTransmission(Addr_Mag); Wire.write(0x4C); // Select Mag register Wire.write(0x00); // Normal Mode, ODR = 10 Hz Wire.endTransmission(); //------------------------------------------------------------// Wire.beginTransmission(Addr_Mag); Wire.write(0x4E); // Select Mag register Wire.write(0x84); // X, Y, Z-Axis enabled Wire.endTransmission(); //------------------------------------------------------------// Wire.beginTransmission(Addr_Mag); Wire.write(0x51); // Select Mag register Wire.write(0x04); // No. of Repetitions for X-Y Axis = 9 Wire.endTransmission(); //------------------------------------------------------------// Wire.beginTransmission(Addr_Mag); Wire.write(0x52); // Select Mag register Wire.write(0x16); // No. of Repetitions for Z-Axis = 15 Wire.endTransmission(); } //=====================================================================================// void BMX055_Accl() { int data[6]; for (int i = 0; i < 6; i++) { Wire.beginTransmission(Addr_Accl); Wire.write((2 + i));// Select data register Wire.endTransmission(); Wire.requestFrom(Addr_Accl, 1);// Request 1 byte of data // Read 6 bytes of data // xAccl lsb, xAccl msb, yAccl lsb, yAccl msb, zAccl lsb, zAccl msb if (Wire.available() == 1) data[i] = Wire.read(); } // Convert the data to 12-bits xAccl = ((data[1] * 256) + (data[0] & 0xF0)) / 16; Serial.println("here"); if (xAccl > 2047) xAccl -= 4096; yAccl = ((data[3] * 256) + (data[2] & 0xF0)) / 16; if (yAccl > 2047) yAccl -= 4096; zAccl = ((data[5] * 256) + (data[4] & 0xF0)) / 16; if (zAccl > 2047) zAccl -= 4096; xAccl = xAccl * 0.0098; // renge +-2g yAccl = yAccl * 0.0098; // renge +-2g zAccl = zAccl * 0.0098; // renge +-2g } //=====================================================================================// void BMX055_Gyro() { int data[6]; for (int i = 0; i < 6; i++) { Wire.beginTransmission(Addr_Gyro); Wire.write((2 + i)); // Select data register Wire.endTransmission(); Wire.requestFrom(Addr_Gyro, 1); // Request 1 byte of data // Read 6 bytes of data // xGyro lsb, xGyro msb, yGyro lsb, yGyro msb, zGyro lsb, zGyro msb if (Wire.available() == 1) data[i] = Wire.read(); } // Convert the data xGyro = (data[1] * 256) + data[0]; if (xGyro > 32767) xGyro -= 65536; yGyro = (data[3] * 256) + data[2]; if (yGyro > 32767) yGyro -= 65536; zGyro = (data[5] * 256) + data[4]; if (zGyro > 32767) zGyro -= 65536; xGyro = xGyro * 0.0038; // Full scale = +/- 125 degree/s yGyro = yGyro * 0.0038; // Full scale = +/- 125 degree/s zGyro = zGyro * 0.0038; // Full scale = +/- 125 degree/s } //=====================================================================================// void BMX055_Mag() { int data[8]; for (int i = 0; i < 8; i++) { Wire.beginTransmission(Addr_Mag); Wire.write((0x42 + i)); // Select data register Wire.endTransmission(); Wire.requestFrom(Addr_Mag, 1); // Request 1 byte of data // Read 6 bytes of data // xMag lsb, xMag msb, yMag lsb, yMag msb, zMag lsb, zMag msb if (Wire.available() == 1) data[i] = Wire.read(); } // Convert the data xMag = ((data[1] <<8) | (data[0]>>3)); if (xMag > 4095) xMag -= 8192; yMag = ((data[3] <<8) | (data[2]>>3)); if (yMag > 4095) yMag -= 8192; zMag = ((data[5] <<8) | (data[4]>>3)); if (zMag > 16383) zMag -= 32768; }     My question is: 1> Is this the correct way(correct registers) to read the magnetometer data? 2> If my code is correct, what happens to my magnetometer raw data? 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