BMX160 magnetometer problem

[mnjirjak · Accepted solution]

OK, I figured it out. Unfortunately I forgot to connect VDDIO pin to the power supply. After I did so and tried the sample code, everything worked like a charm. Thank you very much for your assistance, I really appreciate it.

For anyone else experiencing the same problem, please make sure you connect VDDIO to power supply. The code that I used can be found here. I modified it a bit and tested everything by reading all three sensors. Here's the code that I used:

#include "bmi160.h"
#include "bmm150.h"

struct bmi160_dev bmi;
struct bmm150_dev bmm;

struct bmi160_sensor_data accel;
struct bmi160_sensor_data gyro;

int8_t bmm150_aux_read(uint8_t id, uint8_t reg_addr, uint8_t *aux_data, uint16_t len);
int8_t bmm150_aux_write(uint8_t id, uint8_t reg_addr, uint8_t *aux_data, uint16_t len);

int main(void)
{
    bmi.id = 0;
    bmi.interface = BMI160_SPI_INTF;
    bmi.read = spi_read_transfer;
    bmi.write = spi_write_transfer;
    bmi.delay_ms = delay;

    bmm.dev_id = BMM150_DEFAULT_I2C_ADDRESS;
    bmm.intf = BMM150_I2C_INTF;
    bmm.read = bmm150_aux_read;
    bmm.write = bmm150_aux_write;
    bmm.delay_ms = delay;

    bmi160_init(&bmi);
  
    bmi.aux_cfg.aux_sensor_enable = BMI160_ENABLE;
    bmi.aux_cfg.aux_i2c_addr = bmm.dev_id;
    bmi.aux_cfg.manual_enable = BMI160_ENABLE;
    bmi.aux_cfg.aux_rd_burst_len = BMI160_AUX_READ_LEN_3;

    bmi160_aux_init(&bmi);
    bmm150_init(&bmm);

    bmi.accel_cfg.odr = BMI160_ACCEL_ODR_100HZ;
    bmi.accel_cfg.range = BMI160_ACCEL_RANGE_2G;
    bmi.accel_cfg.bw = BMI160_ACCEL_BW_NORMAL_AVG4;
    bmi.accel_cfg.power = BMI160_ACCEL_NORMAL_MODE;

    bmi.gyro_cfg.odr = BMI160_GYRO_ODR_100HZ;
    bmi.gyro_cfg.range = BMI160_GYRO_RANGE_2000_DPS;
    bmi.gyro_cfg.bw = BMI160_GYRO_BW_NORMAL_MODE;
    bmi.gyro_cfg.power = BMI160_GYRO_NORMAL_MODE;

    bmi160_set_sens_conf(&bmi);

    bmm.settings.preset_mode = BMM150_PRESETMODE_REGULAR;
    bmm150_set_presetmode(&bmm);

    bmm.settings.pwr_mode = BMM150_FORCED_MODE;
    bmm150_set_op_mode(&bmm);


	uint8_t aux_addr = 0x42;	
	uint8_t mag_data[8] = {0};
	
	uint8_t index;

	bmi.aux_cfg.aux_odr = 8;
	bmi160_config_aux_mode(&bmi);
	
	bmi160_set_aux_auto_mode(&aux_addr, &bmi);


    while(1) {
        bmi160_get_sensor_data((BMI160_ACCEL_SEL | BMI160_GYRO_SEL), &accel, &gyro, &bmi);
    	bmi160_read_aux_data_auto_mode(mag_data, &bmi);
    	bmm150_aux_mag_data(mag_data, &bmm);

        printf("****************\n");
        printf("ACC X: %d, Y: %d, Z: %d\n", accel.x, accel.y, accel.z);
        printf("GYRO X: %d, Y: %d, Z: %d\n", gyro.x, gyro.y, gyro.z);
    	printf("MAG X : %d Y : %d Z : %d\n", bmm.data.x, bmm.data.y, bmm.data.z);
        printf("################\n");
    }
}

int8_t bmm150_aux_read(uint8_t id, uint8_t reg_addr, uint8_t *reg_data, uint16_t len) {
    (void) id;
    return bmi160_aux_read(reg_addr, reg_data, len, &bmi);
}

int8_t bmm150_aux_write(uint8_t id, uint8_t reg_addr, uint8_t *reg_data, uint16_t len) {
    (void) id;
    return bmi160_aux_write(reg_addr, reg_data, len, &bmi);
}

where spi_read_transfer, spi_write_transfer and delay represent master-chip-specific functions for spi transfers and delay.

The sample data that I got:

****************
ACC X: -16140, Y: 27, Z: -551
GYRO X: 7, Y: 3, Z: -5
MAG X : 37 Y : -12 Z : 6
################
****************
ACC X: -16171, Y: -18, Z: -516
GYRO X: 8, Y: 2, Z: -5
MAG X : 36 Y : -12 Z : 7
################
****************
ACC X: -16132, Y: -13, Z: -550
GYRO X: 8, Y: 3, Z: -5
MAG X : 37 Y : -12 Z : 8
################

Once again, thank you for your help!

Kind regards,

Marko Njirjak

[o_o]

Great !

Glad your issue is fixed, and thanks for posting your solution here!

[swapnilsayan]

Hi, could you show your implementation of user_spi_read/write and if possible user_i2c_read and write?

[mnjirjak]

Hi swapnilsayan,

sorry for the late response. While working on this project, I used Nordic nRF52840 as the master chip. Accordingly, the SPI and I2C functions are somewhat connected to the Nordic SDK.

SPI:

void delay(uint32_t period) {
    nrf_delay_ms(period);
}

int8_t spi_read_transfer(uint8_t dev_id, uint8_t reg_addr, uint8_t *reg_data, uint16_t length)
{
    ret_code_t ret;
    uint8_t read_temp[length + 1];
    uint8_t counter = 0;

    while (counter < 3) {
        ret = nrf_drv_spi_transfer(&spi, &reg_addr, 1, read_temp, length + 1);
        if (ret == NRF_SUCCESS) {
            break;
        } else {
            ++counter;
        }
    }

    if (counter >= 3) {
        APP_ERROR_CHECK(ret);
    }

    nrf_delay_us(500); 

    for (int i = 1; i < length + 1; ++i) {
        reg_data[i - 1] = read_temp[i];
    }
    return (int8_t)ret;	
}

int8_t spi_write_transfer(uint8_t dev_id, uint8_t reg_addr, uint8_t *reg_data, uint16_t length)
{
    ret_code_t ret;
    uint8_t write_temp[length + 1];
    write_temp[0] = reg_addr;
    uint8_t counter = 0;

    for (int i = 1; i < length + 1; ++i) {
        write_temp[i] = reg_data[i-1];
    }

    while (counter < 3) {
        ret = nrf_drv_spi_transfer(&spi, write_temp, length + 1, NULL, 0);
        if (ret == NRF_SUCCESS) {
            break;
        } else {
            ++counter;
        }
    }

    if (counter >= 3) {
        APP_ERROR_CHECK(ret);
    }
    
    nrf_delay_us(500) ;

    return (int8_t)ret;	
}

void setupSPI() {
    nrf_drv_spi_config_t spi_config = NRF_DRV_SPI_DEFAULT_CONFIG;
    spi_config.frequency = NRF_DRV_SPI_FREQ_8M;
    spi_config.ss_pin   = SPI_SS_PIN;
    spi_config.miso_pin = SPI_MISO_PIN;
    spi_config.mosi_pin = SPI_MOSI_PIN;
    spi_config.sck_pin  = SPI_SCK_PIN;
    APP_ERROR_CHECK(nrf_drv_spi_init(&spi, &spi_config, NULL, NULL));
}

 I didn't actually use I2C, but it was used internally by the BMI160 and BMM150 drivers, I guess. I used BMX160, which can be controlled with BMI160+BMM150 drivers. Sensors are initialized as follows:

struct bmi160_dev bmi;
struct bmm150_dev bmm;

void initializeSensors() {
    bmi.id = 0;
    bmi.interface = BMI160_SPI_INTF;
    bmi.read = spi_read_transfer;
    bmi.write = spi_write_transfer;
    bmi.delay_ms = delay;

    bmm.dev_id = BMM150_DEFAULT_I2C_ADDRESS;
    bmm.intf = BMM150_I2C_INTF;
    bmm.read = bmm150_aux_read;
    bmm.write = bmm150_aux_write;
    bmm.delay_ms = delay;

    APP_ERROR_CHECK(bmi160_init(&bmi));
  
    bmi.aux_cfg.aux_sensor_enable = BMI160_ENABLE;
    bmi.aux_cfg.aux_i2c_addr = bmm.dev_id;
    bmi.aux_cfg.manual_enable = BMI160_ENABLE;

    APP_ERROR_CHECK(bmi160_aux_init(&bmi));
    APP_ERROR_CHECK(bmm150_init(&bmm));
}

 More details about this can be found on the official Bosch Github repos (https://github.com/BoschSensortec/BMI160_driver, https://github.com/BoschSensortec/BMM150-Sensor-API).

Kind regards,

Marko Njirjak