This package contains the Bosch Sensortec's BMM150 Magnetometer sensor driver (sensor API)
The sensor driver package includes bmm150.h, bmm150.c and bmm150_defs.h files
bmm150 sensor driver supports the following Bosch MEMS sensors
- BMM050
- BMM150
- BMC150 - Combination of bma2x2 + bmm150 APIs
- BMC056 - Combination of bma2x2 + bmm150 APIs
- BMX055 - Combination of bma2x2 + bmg160 + bmm150 APIs
| File | Version | Date |
|---|---|---|
| bmm150.c | 1.0.0 | 12 Sep 2017 |
| bmm150.h | 1.0.0 | 12 Sep 2017 |
| bmm150_defs.h | 1.0.0 | 12 Sep 2017 |
- Integrate bmm150.h, bmm150_defs.h and bmm150.c file in to your project.
- Include the bmm150.h file in your code like below.
#include "bmm150.h"- bmm150_defs.h : This header file has the constants, macros and datatype declarations.
- bmm150.h : This header file contains the declarations of the sensor driver APIs.
- bmm150.c : This source file contains the definitions of the sensor driver APIs.
- SPI 4-wire
- I2C
To initialize the sensor, you will first need to create a device structure. You can do this by creating an instance of the structure bmm150_dev. Then go on to fill in the various parameters as shown below.
struct bmm150_dev dev;
int8_t rslt = BMM150_OK;
/* Sensor interface over SPI with native chip select line */
dev.dev_id = 0;
dev.intf = BMM150_SPI_INTF;
dev.read = user_spi_read;
dev.write = user_spi_write;
dev.delay_ms = user_delay_ms;
rslt = bmm150_init(&dev);struct bmm150_dev dev;
int8_t rslt = BMM150_OK;
/* Sensor interface over I2C */
dev.dev_id = BMM150_DEFAULT_I2C_ADDRESS;
dev.intf = BMM150_I2C_INTF;
dev.read = user_i2c_read;
dev.write = user_i2c_write;
dev.delay_ms = user_delay_ms;
rslt = bmm150_init(&dev);int8_t set_sensor_settings(struct bmm150_dev *dev)
{
int8_t rslt;
/* Setting the power mode as normal */
dev->settings.pwr_mode = BMM150_NORMAL_MODE;
rslt = bmm150_set_op_mode(dev);
/* Setting the preset mode as Low power mode
i.e. data rate = 10Hz XY-rep = 1 Z-rep = 2*/
dev->settings.preset_mode = BMM150_PRESETMODE_LOWPOWER;
rslt = bmm150_set_presetmode(dev);
return rslt;
}- Sensor data should be read after setting the desired power mode and preset mode.
Ensure that the macro "BMM150_USE_FLOATING_POINT" in the bmm150_defs.h file is commented out
int8_t read_sensor_data(struct bmm150_dev *dev)
{
int8_t rslt;
/* Mag data for X,Y,Z axis are stored inside the
bmm150_dev structure in int16_t format */
rslt = bmm150_read_mag_data(dev);
/* Print the Mag data */
printf("\n Magnetometer data \n");
printf("MAG X : %d \t MAG Y : %d \t MAG Z : %d \n"
,dev->data.x, dev->data.y, dev->data.z);
return rslt;
}Enable the macro "BMM150_USE_FLOATING_POINT" in the bmm150_defs.h file (or) enable "BMM150_USE_FLOATING_POINT" in the compiler option of your project
int8_t read_sensor_data(struct bmm150_dev *dev)
{
int8_t rslt;
/* Mag data for X,Y,Z axis are stored inside the
bmm150_dev structure in float format */
rslt = bmm150_read_mag_data(dev);
/* Print the Mag data */
printf("\n Magnetometer data \n");
printf("MAG X : %0.2f \t MAG Y : %0.2f \t MAG Z : %0.2f \n"
,dev->data.x, dev->data.y, dev->data.z);
return rslt;
}int8_t perform_self_tests(struct bmm150_dev *dev)
{
int8_t rslt;
/* Perform Normal Self test */
rslt = bmm150_perform_self_test(BMM150_NORMAL_SELF_TEST, dev);
printf("\n NORMAL SELF TEST RESULT : %d",rslt);
/* Validate normal self test result */
if (rslt == BMM150_OK) {
printf("\n Normal Self test passed ");
} else {
printf("\n Normal Self test failed ");
}
/* Perform Advanced Self test */
rslt |= bmm150_perform_self_test(BMM150_ADVANCED_SELF_TEST, dev);
printf("\n ADVANCED SELF TEST RESULT : %d",rslt);
/* Validate Advanced self test result */
if (rslt == BMM150_OK) {
printf("\n Advanced Self test passed ");
} else {
printf("\n Advanced Self test failed ");
}
return rslt;
}Configuring the interrupt
int8_t drdy_interrupt_configure(struct bmm150_dev *dev)
{
int8_t rslt;
uint16_t desired_settings;
/* Set the macros to enable DRDY pin */
desired_settings = BMM150_DRDY_PIN_EN_SEL | BMM150_DRDY_POLARITY_SEL;
/* Set the drdy_pin_en to enable the drdy interrupt */
dev->settings.int_settings.drdy_pin_en = BMM150_INT_ENABLE;
/* Set the polarity as active high on the DRDY pin */
dev->settings.int_settings.drdy_polarity = BMM150_ACTIVE_HIGH_POLARITY;
/* Set the configurations in the sensor */
rslt = bmm150_set_sensor_settings(desired_settings, dev);
return rslt;
}Read the interrupt status continuously to check for interrupt assertion (Polling method)
int8_t drdy_interrupt_handling(struct bmm150_dev *dev)
{
int8_t rslt;
/* Read the interrupt status */
rslt = bmm150_get_interrupt_status(dev);
if (rslt == BMM150_OK) {
if (dev->int_status & BMM150_DATA_READY_INT) {
/* Interrupt asserted - Read mag data */
rslt = bmm150_read_mag_data(dev);
printf("\n MAG DATA ");
printf("\n MAG X : %d MAG Y : %d MAG Z : %d "
,dev->data.x,dev->data.y,dev->data.z);
} else {
/*Interrupt not asserted */
printf("\n Data is not ready yet");
}
}
return rslt;
}