Aucune donnée du magnétomètre sur MPU9255

Question

J'ai un problème avec la lecture des données du magnétomètre sur un MPU9255. L'accéléromètre et le gyroscope fonctionnent correctement, mais je ne reçois aucune donnée du magnétomètre. Je travaille sur la cible STM32F103.

Quelqu'un at-il une idée de ce qui ne va pas avec le code ci-dessous?

uint8_t Settings = 0x00; 
uint8_t SettingsM = 0x00; 
uint8_t SettingsL = 0x22; //mode2 16bit 
//settings accelerometer and gyroscope 
HAL_I2C_Mem_Write(&hi2c1, 0xD0, 27, I2C_MEMADD_SIZE_8BIT, &Settings,1,1000); 
HAL_I2C_Mem_Write(&hi2c1, 0xD0, 28, I2C_MEMADD_SIZE_8BIT, &Settings,1,1000); 

//Power Down mode 
HAL_I2C_Mem_Write(&hi2c1, 0x0C, 0x0A, I2C_MEMADD_SIZE_8BIT, &SettingsM,1,1000); 
HAL_Delay(100); 
//16 bit output mode 2 
HAL_I2C_Mem_Write(&hi2c1, 0x0C, 0x0A, I2C_MEMADD_SIZE_8BIT, &SettingsL,1,1000); 
while (1) 
{ 
    //A X 
    HAL_I2C_Mem_Read(&hi2c1, 0xD0, 59, I2C_MEMADD_SIZE_8BIT, &DAHx,1,100); 
    HAL_I2C_Mem_Read(&hi2c1, 0xD0, 60, I2C_MEMADD_SIZE_8BIT, &DALx,1,100); 
    //A Y 
    HAL_I2C_Mem_Read(&hi2c1, 0xD0, 61, I2C_MEMADD_SIZE_8BIT, &DAHy,1,100); 
    HAL_I2C_Mem_Read(&hi2c1, 0xD0, 62, I2C_MEMADD_SIZE_8BIT, &DALy,1,100); 
    //A Z 
    HAL_I2C_Mem_Read(&hi2c1, 0xD0, 63, I2C_MEMADD_SIZE_8BIT, &DAHz,1,100); 
    HAL_I2C_Mem_Read(&hi2c1, 0xD0, 64, I2C_MEMADD_SIZE_8BIT, &DALz,1,100); 
    //Temp 
    HAL_I2C_Mem_Read(&hi2c1, 0xD0, 65, I2C_MEMADD_SIZE_8BIT, &DHT,1,100); 
    HAL_I2C_Mem_Read(&hi2c1, 0xD0, 66, I2C_MEMADD_SIZE_8BIT, &DLT,1,100); 
    //G X 
    HAL_I2C_Mem_Read(&hi2c1, 0xD0, 67, I2C_MEMADD_SIZE_8BIT, &DGHx,1,100); 
    HAL_I2C_Mem_Read(&hi2c1, 0xD0, 68, I2C_MEMADD_SIZE_8BIT, &DGLx,1,100); 
    //G Y 
    HAL_I2C_Mem_Read(&hi2c1, 0xD0, 69, I2C_MEMADD_SIZE_8BIT, &DGHy,1,100); 
    HAL_I2C_Mem_Read(&hi2c1, 0xD0, 70, I2C_MEMADD_SIZE_8BIT, &DGLy,1,100); 
    //G Z 
    HAL_I2C_Mem_Read(&hi2c1, 0xD0, 71, I2C_MEMADD_SIZE_8BIT, &DGHz,1,100); 
    HAL_I2C_Mem_Read(&hi2c1, 0xD0, 72, I2C_MEMADD_SIZE_8BIT, &DGLz,1,100); 

    do 
    { 
     HAL_I2C_Mem_Read(&hi2c1, 0x0C, 0x02, I2C_MEMADD_SIZE_8BIT, &ST1,1,100); 
    } 
    while (!(ST1&0x01)); 

    //0x0C - adress AK8963, 0x03-0x08 => HLx-HHz 
    HAL_I2C_Mem_Read(&hi2c1, 0x0C, 0x03, I2C_MEMADD_SIZE_8BIT, &HLx,1,100); 
    HAL_I2C_Mem_Read(&hi2c1, 0x0C, 0x04, I2C_MEMADD_SIZE_8BIT, &HHx,1,100); 
    HAL_I2C_Mem_Read(&hi2c1, 0x0C, 0x05, I2C_MEMADD_SIZE_8BIT, &HLy,1,100); 
    HAL_I2C_Mem_Read(&hi2c1, 0x0C, 0x06, I2C_MEMADD_SIZE_8BIT, &HHy,1,100); 
    HAL_I2C_Mem_Read(&hi2c1, 0x0C, 0x07, I2C_MEMADD_SIZE_8BIT, &HLz,1,100); 
    HAL_I2C_Mem_Read(&hi2c1, 0x0C, 0x08, I2C_MEMADD_SIZE_8BIT, &HHz,1,100); 

    HAL_I2C_Mem_Read(&hi2c1, 0x0C, 0x09, I2C_MEMADD_SIZE_8BIT, &H,1,100); 

    //accelerometer 
    Ax = (int16_t)(DAHx << 8 | DALx); 
    Ay = (int16_t)(DAHy << 8 | DALy); 
    Az = (int16_t)(DAHz << 8 | DALz); 
    //temperature 
    T = (int16_t)(DHT << 8 | DLT); 
    //gyroscope 
    Gx = (int16_t)(DGHx << 8 | DGLx); 
    Gy = (int16_t)(DGHy << 8 | DGLy); 
    Gz = (int16_t)(DGHz << 8 | DGLz); 
    //magnetometer 
    Hx= (int16_t)(HHx << 8 | HLx); 
    Hy= (int16_t)(HHy << 8 | HLy); 
    Hz= (int16_t)(HHz << 8 | HLz); 

    Ax_g = (float)Ax/16384.0; 
    Ay_g = (float)Ay/16384.0; 
    Az_g = (float)Az/16384.0; 
    Gx_g = (float)Gx/131.0; 
    Gy_g = (float)Gy/131.0; 
    Gz_g = (float)Gz/131.0; 

    arx = (180.0/3.141592) * atanf(Ax_g/sqrtf(Ay_g*Ay_g + Az_g*Az_g)); 
    ary = (180.0/3.141592) * atanf(Ay_g/sqrtf((Ax_g*Ax_g + Az_g*Az_g))); 

    rx = (0.96 * arx) + (0.04 * Gx_g); 
    ry = (0.96 * ary) + (0.04 * Gy_g); 
} 

Answer 1

Vous devez activer le mode by-pass I2C sur le MPU9255 pour communiquer avec le AK8963 directement. Mettez le bit BYPASS_EN dans la INT Pin/Bypass Activer registre de configuration (registre 55) au début de votre programme avec:

uint8_t BypassEnable = 0x02; 
HAL_I2C_Mem_Write(&hi2c1, 0xD0, 55, I2C_MEMADD_SIZE_8BIT, &BypassEnable,1,1000); 

Voir ici pour un exemple de travail: Arduino Sensor 10DOF MPU9255 cannot fetch magnetometer data