9 years, 2 months ago.

Configuring MPU9250 magnometer

Hello,

I am using a FRDM K22F which is connected to a MPU9250 using SPI.

I can get data by polling but not using FIFO.

To be more precise I CAN get accel and gyro data but NOT magnometer data.

This is driving me crazy....

Here is a sample result :

<<block>>
count= 18,  1072 us,  932.836 Hz,ax=   688,ay=-16136,az= -1120,gx=   324,gy=   417,gz=    45,mx=     0,my=     0,mz=     0
count= 18,   989 us, 1011.122 Hz,ax=   628,ay=-16172,az= -1160,gx=   306,gy=   399,gz=    33,mx=     0,my=     0,mz=     0
count= 18,   989 us, 1011.122 Hz,ax=   732,ay=-16216,az= -1124,gx=   332,gy=   422,gz=    35,mx=     0,my=     0,mz=     0
count= 18,   989 us, 1011.122 Hz,ax=   768,ay=-16152,az= -1032,gx=   350,gy=   393,gz=    46,mx=     0,my=     0,mz=     0
count= 18,   989 us, 1011.122 Hz,ax=   764,ay=-16188,az= -1232,gx=   359,gy=   397,gz=    60,mx=     0,my=     0,mz=     0
count= 18,  1072 us,  932.836 Hz,ax=   792,ay=-16236,az= -1072,gx=   350,gy=   405,gz=    66,mx=     0,my=     0,mz=     0
count= 18,   989 us, 1011.122 Hz,ax=   712,ay=-16196,az= -1084,gx=   350,gy=   398,gz=    86,mx=     0,my=     0,mz=     0
count= 18,   988 us, 1012.146 Hz,ax=   636,ay=-16280,az= -1060,gx=   341,gy=   376,gz=    47,mx=     0,my=     0,mz=     0
count= 18,   988 us, 1012.146 Hz,ax=   644,ay=-16252,az= -1128,gx=   332,gy=   399,gz=    80,mx=     0,my=     0,mz=     0
count= 18,   989 us, 1011.122 Hz,ax=   688,ay=-16212,az= -1060,gx=   308,gy=   412,gz=    50,mx=     0,my=     0,mz=     0
<</block>>

Source code used :

mpu9250 on FRDM K22F board using spi and FIFO

#include "mbed.h"

// See also MPU-9250 Register Map and Descriptions, Revision 4.0, RM-MPU-9250A-00, Rev. 1.4, 9/9/2013 for registers not listed in
// above document; the MPU9250 and MPU9150 are virtually identical but the latter has a different register map
//
//Magnetometer Registers
#define AK8963_ADDRESS   0x0C
#define WHO_AM_I_AK8963  0x00 // should return 0x48
#define INFO             0x01
#define AK8963_ST1       0x02  // data ready status bit 0
#define AK8963_XOUT_L	 0x03  // data
#define AK8963_XOUT_H	 0x04
#define AK8963_YOUT_L	 0x05
#define AK8963_YOUT_H	 0x06
#define AK8963_ZOUT_L	 0x07
#define AK8963_ZOUT_H	 0x08
#define AK8963_ST2       0x09  // Data overflow bit 3 and data read error status bit 2
#define AK8963_CNTL1      0x0A  // Power down (0000), single-measurement (0001), self-test (1000) and Fuse ROM (1111) modes on bits 3:0
#define AK8963_CNTL2      0x0B
#define AK8963_ASTC      0x0C  // Self test control
#define AK8963_I2CDIS    0x0F  // I2C disable
#define AK8963_ASAX      0x10  // Fuse ROM x-axis sensitivity adjustment value
#define AK8963_ASAY      0x11  // Fuse ROM y-axis sensitivity adjustment value
#define AK8963_ASAZ      0x12  // Fuse ROM z-axis sensitivity adjustment value

#define SELF_TEST_X_GYRO 0x00
#define SELF_TEST_Y_GYRO 0x01
#define SELF_TEST_Z_GYRO 0x02

/*#define X_FINE_GAIN      0x03 // [7:0] fine gain
#define Y_FINE_GAIN      0x04
#define Z_FINE_GAIN      0x05
#define XA_OFFSET_H      0x06 // User-defined trim values for accelerometer
#define XA_OFFSET_L_TC   0x07
#define YA_OFFSET_H      0x08
#define YA_OFFSET_L_TC   0x09
#define ZA_OFFSET_H      0x0A
#define ZA_OFFSET_L_TC   0x0B */

#define SELF_TEST_X_ACCEL 0x0D
#define SELF_TEST_Y_ACCEL 0x0E
#define SELF_TEST_Z_ACCEL 0x0F

#define SELF_TEST_A      0x10

#define XG_OFFSET_H      0x13  // User-defined trim values for gyroscope
#define XG_OFFSET_L      0x14
#define YG_OFFSET_H      0x15
#define YG_OFFSET_L      0x16
#define ZG_OFFSET_H      0x17
#define ZG_OFFSET_L      0x18
#define SMPLRT_DIV       0x19
#define CONFIG           0x1A
#define GYRO_CONFIG      0x1B
#define ACCEL_CONFIG     0x1C
#define ACCEL_CONFIG2    0x1D
#define LP_ACCEL_ODR     0x1E
#define WOM_THR          0x1F

#define MOT_DUR          0x20  // Duration counter threshold for motion interrupt generation, 1 kHz rate, LSB = 1 ms
#define ZMOT_THR         0x21  // Zero-motion detection threshold bits [7:0]
#define ZRMOT_DUR        0x22  // Duration counter threshold for zero motion interrupt generation, 16 Hz rate, LSB = 64 ms

#define FIFO_EN          0x23
#define I2C_MST_CTRL     0x24
#define I2C_SLV0_ADDR    0x25
#define I2C_SLV0_REG     0x26
#define I2C_SLV0_CTRL    0x27
#define I2C_SLV1_ADDR    0x28
#define I2C_SLV1_REG     0x29
#define I2C_SLV1_CTRL    0x2A
#define I2C_SLV2_ADDR    0x2B
#define I2C_SLV2_REG     0x2C
#define I2C_SLV2_CTRL    0x2D
#define I2C_SLV3_ADDR    0x2E
#define I2C_SLV3_REG     0x2F
#define I2C_SLV3_CTRL    0x30
#define I2C_SLV4_ADDR    0x31
#define I2C_SLV4_REG     0x32
#define I2C_SLV4_DO      0x33
#define I2C_SLV4_CTRL    0x34
#define I2C_SLV4_DI      0x35
#define I2C_MST_STATUS   0x36
#define INT_PIN_CFG      0x37
#define INT_ENABLE       0x38
#define DMP_INT_STATUS   0x39  // Check DMP interrupt
#define INT_STATUS       0x3A
#define ACCEL_XOUT_H     0x3B
#define ACCEL_XOUT_L     0x3C
#define ACCEL_YOUT_H     0x3D
#define ACCEL_YOUT_L     0x3E
#define ACCEL_ZOUT_H     0x3F
#define ACCEL_ZOUT_L     0x40
#define TEMP_OUT_H       0x41
#define TEMP_OUT_L       0x42
#define GYRO_XOUT_H      0x43
#define GYRO_XOUT_L      0x44
#define GYRO_YOUT_H      0x45
#define GYRO_YOUT_L      0x46
#define GYRO_ZOUT_H      0x47
#define GYRO_ZOUT_L      0x48
#define EXT_SENS_DATA_00 0x49
#define EXT_SENS_DATA_01 0x4A
#define EXT_SENS_DATA_02 0x4B
#define EXT_SENS_DATA_03 0x4C
#define EXT_SENS_DATA_04 0x4D
#define EXT_SENS_DATA_05 0x4E
#define EXT_SENS_DATA_06 0x4F
#define EXT_SENS_DATA_07 0x50
#define EXT_SENS_DATA_08 0x51
#define EXT_SENS_DATA_09 0x52
#define EXT_SENS_DATA_10 0x53
#define EXT_SENS_DATA_11 0x54
#define EXT_SENS_DATA_12 0x55
#define EXT_SENS_DATA_13 0x56
#define EXT_SENS_DATA_14 0x57
#define EXT_SENS_DATA_15 0x58
#define EXT_SENS_DATA_16 0x59
#define EXT_SENS_DATA_17 0x5A
#define EXT_SENS_DATA_18 0x5B
#define EXT_SENS_DATA_19 0x5C
#define EXT_SENS_DATA_20 0x5D
#define EXT_SENS_DATA_21 0x5E
#define EXT_SENS_DATA_22 0x5F
#define EXT_SENS_DATA_23 0x60
#define MOT_DETECT_STATUS 0x61
#define I2C_SLV0_DO      0x63
#define I2C_SLV1_DO      0x64
#define I2C_SLV2_DO      0x65
#define I2C_SLV3_DO      0x66
#define I2C_MST_DELAY_CTRL 0x67
#define SIGNAL_PATH_RESET  0x68
#define MOT_DETECT_CTRL  0x69
#define USER_CTRL        0x6A  // Bit 7 enable DMP, bit 3 reset DMP
#define PWR_MGMT_1       0x6B // Device defaults to the SLEEP mode
#define PWR_MGMT_2       0x6C
#define DMP_BANK         0x6D  // Activates a specific bank in the DMP
#define DMP_RW_PNT       0x6E  // Set read/write pointer to a specific start address in specified DMP bank
#define DMP_REG          0x6F  // Register in DMP from which to read or to which to write
#define DMP_REG_1        0x70
#define DMP_REG_2        0x71
#define FIFO_COUNTH      0x72
#define FIFO_COUNTL      0x73
#define FIFO_R_W         0x74
#define WHO_AM_I_MPU9250 0x75 // Should return 0x71
#define XA_OFFSET_H      0x77
#define XA_OFFSET_L      0x78
#define YA_OFFSET_H      0x7A
#define YA_OFFSET_L      0x7B
#define ZA_OFFSET_H      0x7D
#define ZA_OFFSET_L      0x7E



#define READ_FLAG   0x80

DigitalOut cs(PTD4);
DigitalOut myled(LED1);
Serial pc(USBTX, USBRX);
SPI spi(PTD6,PTD7,PTD5);
Timer timer;



void select()

{
    //Set CS low to start transmission (interrupts conversion)
    cs = 0;
}
void deselect()
{
    //Set CS high to stop transmission (restarts conversion)
    cs = 1;
}


unsigned int writeByte( uint8_t WriteAddr, uint8_t WriteData )
{
    unsigned int temp_val;
    select();
    spi.write(WriteAddr);
    temp_val=spi.write(WriteData);
    deselect();
    wait_us(50);
    return temp_val;
}
unsigned int  readByte( uint8_t WriteAddr, uint8_t WriteData )
{
    return writeByte(WriteAddr | 0x80,WriteData);
}
void readBytes( uint8_t ReadAddr, uint8_t *ReadBuf, unsigned int Bytes )
{
    unsigned int  i = 0;

    select();
    spi.write(ReadAddr | 0x80);
    for(i=0; i<Bytes; i++)
        ReadBuf[i] = spi.write(0x00);
    deselect();
    wait_us(50);
}


#define PACKET_SIZE 18




uint8_t AK8963ReadByte(uint8_t reg)
{
    uint8_t response;
    writeByte(I2C_SLV0_ADDR,AK8963_ADDRESS|READ_FLAG); //Set the I2C slave addres of AK8963 and set for read.
    writeByte(I2C_SLV0_REG, reg); //I2C slave 0 register address from where to begin data transfer
    writeByte(I2C_SLV0_CTRL, 0x81); //Read 1 byte from the magnetometer

    wait(0.001);
    response=readByte(EXT_SENS_DATA_00,0x00);    //Read I2C

    return response;
}


int main()
{


    timer.start();
    pc.baud(230400);


    uint8_t data[PACKET_SIZE]; // data array to hold accelerometer and gyro x, y, z, data
    uint16_t ii, packet_count, fifo_count;

    // reset device
    writeByte( PWR_MGMT_1, 0x80); // toggle reset device
    wait_ms(100);
    // get stable time source; Auto select clock source to be PLL gyroscope reference if ready
    // else use the internal oscillator, bits 2:0 = 001
    writeByte( PWR_MGMT_1, 0x01);
    writeByte( PWR_MGMT_2, 0x00);
    wait_ms(200);
    // Configure device for bias calculation
    writeByte( FIFO_EN, 0x00); // Disable FIFO
    writeByte( PWR_MGMT_1, 0x00); // Turn on internal clock source

    writeByte( CONFIG, 0x01); // Set low-pass filter to 188 Hz
    writeByte( SMPLRT_DIV, 0x00); // Set sample rate to 1 kHz
    writeByte( GYRO_CONFIG, 0x00); // Set gyro full-scale to 250 degrees per second, maximum sensitivity
    writeByte( ACCEL_CONFIG, 0x00); // Set accelerometer full-scale to 2 g, maximum sensitivity


    writeByte(USER_CTRL,0x20);                   // I2C Master mode
    writeByte(I2C_MST_CTRL,0x0D);

    printf("\n\nAK8963Whoami=%3d\n",AK8963ReadByte(WHO_AM_I_AK8963));


    // Configure magnometer :
    writeByte(USER_CTRL,0x20);                   // I2C Master mode
    writeByte(I2C_MST_CTRL,0x0D);

    writeByte(I2C_SLV0_ADDR,AK8963_ADDRESS);
    writeByte(I2C_SLV0_REG,AK8963_CNTL2);
    writeByte(I2C_SLV0_CTRL,0x81);
    writeByte(I2C_SLV0_DO,0x01); // reset device
    writeByte(I2C_SLV0_CTRL,0x81);
    wait_ms(500);

    writeByte(I2C_SLV0_ADDR,AK8963_ADDRESS);
    writeByte(I2C_SLV0_REG,AK8963_CNTL1);
    writeByte(I2C_SLV0_CTRL,0x81); // Enable i2c and write 1 bytes
    writeByte(I2C_SLV0_DO,0x12);
    writeByte(I2C_SLV0_CTRL,0x81); // Enable i2c and write 1 bytes

    //writeByte(I2C_SLV0_CTRL,0x81); // Enable i2c and write 1 bytes
    wait(0.001);

    printf("CNTL1=%3d\n",AK8963ReadByte(AK8963_CNTL1));

    printf("ASAX=%3d\n",AK8963ReadByte(AK8963_ASAX));
    printf("ASAY=%3d\n",AK8963ReadByte(AK8963_ASAY));
    printf("ASAZ=%3d\n",AK8963ReadByte(AK8963_ASAZ));



    wait_ms(3000);

    writeByte(I2C_SLV1_ADDR,AK8963_ADDRESS|READ_FLAG); // Magneto address

    writeByte(I2C_SLV1_REG,AK8963_CNTL1);
    writeByte(I2C_SLV1_CTRL,0x81); // Enable i2c and write 1 bytes
    writeByte(I2C_SLV1_DO,0x12);
    writeByte(I2C_SLV1_CTRL,0x81); // Enable i2c and write 1 bytes

    writeByte(I2C_SLV1_REG,AK8963_XOUT_L); // Address of the first data register
    writeByte(I2C_SLV1_CTRL,0x86); // Enable reading and read 6 bytes

    int lastTime=timer.read_us();
    int lastTimePrint=timer.read_us();
    int now=lastTime;



    writeByte( USER_CTRL, 0x0C); // Reset FIFO and DMP
    wait_ms(150);

    // Configure FIFO to capture accelerometer and gyro data for bias calculation

    writeByte( USER_CTRL, 0b01000000); // Enable FIFO
    writeByte( FIFO_EN, 0b01111010); // Enable gyro and accelerometer sensors for FIFO (max size 512 bytes in MPU-9150)


    while(1)
    {

        readBytes(FIFO_COUNTH,data,2); // read FIFO sample count
        fifo_count = ((uint16_t)data[0] << 8) | data[1];
        packet_count = fifo_count/PACKET_SIZE;// How many sets of full gyro and accelerometer data for averaging

        for (ii = 0; ii < packet_count; ii++)
        {
            int16_t accel[3] = {0, 0, 0};
            int16_t  gyro[3] = {0, 0, 0};
            int16_t  mag[3] = {0, 0, 0};

            readBytes( FIFO_R_W,  data,PACKET_SIZE); // read data for averaging
            accel[0] = (int16_t) (((int16_t)data[0] << 8) | data[1] ) ; // Form signed 16-bit integer for each sample in FIFO
            accel[1] = (int16_t) (((int16_t)data[2] << 8) | data[3] ) ;
            accel[2] = (int16_t) (((int16_t)data[4] << 8) | data[5] ) ;

            gyro[0] = (int16_t) (((int16_t)data[6] << 8) | data[7] ) ;
            gyro[1] = (int16_t) (((int16_t)data[8] << 8) | data[9] ) ;
            gyro[2] = (int16_t) (((int16_t)data[10] << 8) | data[11]) ;
            if(PACKET_SIZE==18)
            {
                mag[0] = (int16_t) (((int16_t)data[12] << 8) | data[13] ) ;
                mag[1] = (int16_t) (((int16_t)data[14] << 8) | data[15] ) ;
                mag[2] = (int16_t) (((int16_t)data[16] << 8) | data[17]) ;
            }

            now=timer.read_us();
            if(now-lastTimePrint>10000)
            {

                if(PACKET_SIZE==18)
                {
                    printf("count=%3d,%6d us,%9.3f Hz,ax=%6d,ay=%6d,az=%6d,gx=%6d,gy=%6d,gz=%6d,mx=%6d,my=%6d,mz=%6d\n",
                           fifo_count,
                           now-lastTime,
                           1.0/((now-lastTime)*1e-6),
                           accel[0],
                            accel[1],
                            accel[2],
                            gyro[0],
                            gyro[1],
                            gyro[2],
                            mag[0],
                            mag[1],
                            mag[2]
                            );
                }
                else if(PACKET_SIZE==12)
                {
                    printf("count=%3d,%6d us,%8.3f Hz,ax=%6d,ay=%6d,az=%6d,gx=%6d,gy=%6d,gz=%6d\n",
                           fifo_count,
                           now-lastTime,
                           1.0/((now-lastTime)*1e-6),
                           accel[0],
                            accel[1],
                            accel[2],
                            gyro[0],
                            gyro[1],
                            gyro[2]
                            );
                }
                lastTimePrint=now;

            }
            lastTime=now;

        }

    }
}


Have you tried using the driver from the components section that comes with a hello world program? ( http://developer.mbed.org/components/MPU-9250/ )

posted by Austin Blackstone 21 Apr 2015

Jacques wants to use SPI, the components section driver uses I2C

posted by Simon Wright 04 Oct 2016

1 Answer

7 years, 10 months ago.

Were you able to solve this issue? I'm struggling with the same problem

Unfortunately not. Sorry

posted by Jacques Charreyron 06 Jul 2016

I fixed it!

The problem was you need big delays after changing modes, for example, after a reset I set 1ms and after entering fuse mode 2ms and that did it!

This of course is nowhere to be found on the spec, because you supposedly only need 100us after switching modes (as per the AK8963 spec) but who knows how long it takes for the I2C Master to communicate with the AK8963 when it receives a command.

Hope this helps!

posted by Raymundo Magana 09 Jul 2016