Introduction

Welcome to the documentation for MPU-925X driver. This driver supports MPU-9250 and MPU-9255 sensors.

Source code is available at Github.

Units

Acceleration from accelerometer: G
Rotation from gyroscope: Degrees per second
Magnetic field from magnetometer: Micro Gauss
Temperature from thermometer: Celsius degree

Compatibility

This driver is designed to be portable. So, it can be used on any platform that has a C compiler which supports C99 standard. See porting guide and examples directory for more information.

Getting Started

Adding to Your Project

Copy mpu925x-driver directory to your project’s drivers directory.
Add inc directory to your toolchain’s include path.
Add src/mpu925x_core.c, src/mpu925x_settings.c and src/mpu925x_internals.c source files to your project’s build toolchain.
Provide bus handle, bus read, bus write and delay functions depending on your platform (see: porting guide).
Include mpu925x.h header to your desired source files.
[EXTRAS] Extra modules can be compiled with program if any of the extra functionalities needed. Extra modules are located in extras directory.

Simple Usage

Example Code

#include "mpu925x.h"

// Create mpu925x_t struct instance.
mpu925x_t mpu925x = {
        .master_specific = {
                .bus_handle = &my_bus_handle,

                // Bus functions
                .bus_read = my_bus_read_function_pointer,
                .bus_write = my_bus_write_function_pointer,
                .delay_ms = my_delay_function_pointer
        },

        .settings = {
                // Other settings
                .accelerometer_scale = mpu925x_2g,
                .gyroscope_scale = mpu925x_250dps,
                .orientation = mpu925x_z_plus
        }
};

// Wait till' initializition is complete. Will be in endless loop if sensor
// is unreachable (wiring is not correct, sensor is damaged...).
while (mpu925x_init(&mpu925x, 0));

while (1) {
        // Get sensor data.
        mpu925x_get_all(&mpu925x);

        // Use sensor data (e.g. print).
        printf("Acceleration: %f, %f, %f\n"
               "Rotation: %f, %f, %f\n"
               "Magnetic field: %f, %f, %f\n",
               mpu925x.sensor_data.acceleration[0], mpu925x.sensor_data.acceleration[1], mpu925x.sensor_data.acceleration[2],
               mpu925x.sensor_data.rotation[0], mpu925x.sensor_data.rotation[1], mpu925x.sensor_data.rotation[2],
               mpu925x.sensor_data.magnetic_field[0], mpu925x.sensor_data.magnetic_field[1], mpu925x.sensor_data.magnetic_field[2],);
}

See advanced usage for more functionalities (e.g. hardware offset cancellation, sensor ranges…).

Porting Guide

This driver needs:

Bus read
Bus write
Delay microseconds
Bus handle (optional, depending on your platform)

function and struct pointers. You must define your own functions and pass their pointers to mpu925x_t struct before initialization.

Given slave address is 7 bit, so if your bus interface needs an 8 bit address, shift slave address to 1 bit left (e.g. address << 1).

Bus Read Function

Bus read functions’ prototype is like this:

uint8_t (*bus_read)(struct mpu925x_t *mpu925x, uint8_t slave_address, uint8_t reg, uint8_t *buffer, uint8_t size);

This function wants to read size byte amount of data from bus slave’s reg register which address is slave_address and stores it in buffer array.

Arduino I2C example:

uint8_t arduino_i2c_read(mpu925x_t *mpu925x, uint8_t slave_address, uint8_t reg, uint8_t *buffer, uint8_t size)
{
  Wire.begin();
  Wire.beginTransmission(slave_address);
  Wire.write(reg);
  Wire.endTransmission(false);
  Wire.requestFrom(slave_address, size);
  for (uint16_t i = 0; i < size; i++) {
        if (Wire.available()) {
          buffer[i] = (uint8_t)Wire.read();
        }
        else {
          return 1;
        }
  }
  return 0;
}

STM32 HAL I2C example:

uint8_t mpu925x_stm32_i2c_hal_read(mpu925x_t *mpu925x, uint8_t slave_address, uint8_t reg, uint8_t *buffer, uint8_t size)
{
        return HAL_I2C_Mem_Read(mpu925x->master_specific.bus_handle, slave_address << 1, reg, 1, buffer, size, HAL_MAX_DELAY);
}

mpu925x.master_specific.bus_read = mpu925x_stm32_i2c_hal_read;

Bus Write Function

Bus write function’s prototype is like this:

uint8_t (*bus_write)(struct mpu925x_t *mpu925x, uint8_t slave_address, uint8_t reg, uint8_t *buffer, uint8_t size);

This function wants to write size byte amount of data from buffer array to bus slave’s reg register which address is slave_address.

Arduino I2C example:

uint8_t arduino_i2c_write(mpu925x_t *mpu925x, uint8_t slave_address, uint8_t reg, uint8_t *buffer, uint8_t size)
{
  Wire.beginTransmission(slave_address);
  Wire.write(reg);
  for (uint16_t i = 0; i < size; i++) {
        Wire.write(buffer[i]);
  }
  Wire.endTransmission();
  return 0;
}

STM32 HAL I2C example:

uint8_t mpu925x_stm32_i2c_hal_write(mpu925x_t *mpu925x, uint8_t slave_address, uint8_t reg, uint8_t *buffer, uint8_t size)
{
        return HAL_I2C_Mem_Write(mpu925x->master_specific.bus_handle, slave_address << 1, reg, 1, buffer, size, HAL_MAX_DELAY);
}

mpu925x.master_specific.bus_write = mpu925x_stm32_i2c_hal_write;

Delay Microseconds Function

Delay microseconds functions prototype is like this:

void (*delay_ms)(struct mpu925x_t *mpu925x, uint32_t delay);

This functions wants to wait at least delay microseconds.

Arduino I2C example:

void arduino_delay_ms(mpu925x_t *mpu925x, uint32_t dly)
{
  delay(dly);
}

STM32 HAL example:

void mpu925x_stm32_hal_delay_ms(mpu925x_t *mpu925x, uint32_t delay)
{
        HAL_Delay(delay);
}

mpu925x.master_specific.delay_ms = mpu925x_stm32_hal_delay_ms;

Bus Handle Struct

Bus handle is for platform specific structs or other types of data. If your platform needs some other information for bus or delay functions, you can pass the pointer and use it in bus or delay functions via mpu925x.master_specific.bus_handle.

STM32 HAL example:

I2C_HandleTypeDef hi2c1;

mpu925x.master_specific.bus_handle = &hi2c1;

Advanced Usage

Initialization

Initialization steps are following:

Define needed functions and pass their pointers (See: porting guide).
Create mpu925x_t struct instance with initial values (See: accelerometer, gyroscope and magnetometer).
Call mpu925x_init() function with created mpu925x_t struct and AD0 pin values.

mpu925x_init() Function

Init function takes mpu925x_t struct and AD0 pin values as parameters. AD0 pin value depends on physical sensor and is most probably 0. See api reference for more info.

Init function will return 0 on success, 1 on accelerometer and gyroscope fail and 2 on magnetometer fail. One can use accelerometer and gyroscope with return value of 2. But with return value of 1, nothing works, so check wiring and sensor damage.

General Settings

Sample Rate Divider

Internal sample rate divider is configurable. See MPU-9250 or MPU-9255’s datasheet for more info.

void mpu925x_set_sample_rate_divider(mpu925x_t *mpu925x, uint8_t sample_rate_divider)

Set sample rate divider.

Parameters

mpu925x – MPU-925X struct pointer.
sample_rate_divider – Sample rate divider sentence.

Clock Source

Internal clock source is configurable.

void mpu925x_set_clock_source(mpu925x_t *mpu925x, mpu925x_clock clock)

Set clock source.

See also

mpu925x_clock

Parameters

mpu925x – MPU-925X struct pointer.
clock – Clock select option.

enum mpu925x_clock

Clock settings for MPU-925X.

Values:

enumerator mpu925x_internal_20_hz_clock

enumerator mpu925x_auto_select_pll

Accelerometer Advanced Usage

Raw And Translated Data

Raw and translated acceleration datas are available. Calling mpu925x_get_acceleration function also calls mpu925x_get_acceleration_raw function internally. Both functions stores data in given mpu925x_t struct.

void mpu925x_get_acceleration(mpu925x_t *mpu925x)

Get acceleration in G’s.

See also

mpu925x_get_acceleration_raw

Parameters: mpu925x – MPU-925X struct pointer.

void mpu925x_get_acceleration_raw(mpu925x_t *mpu925x)

Get raw acceleration data.

See also

mpu925x_get_acceleration

Parameters: mpu925x – MPU-925X struct pointer.

Full-Scale Select

One can set accelerometer full-scale range of 2g, 4g, 8g and 16g.

void mpu925x_set_accelerometer_scale(mpu925x_t *mpu925x, mpu925x_accelerometer_scale scale)

Set accelerometer full-scale range.

Parameters

mpu925x – MPU-925X struct pointer.
scale – Accelerometer full-scale range to be set.

enum mpu925x_accelerometer_scale

Accelerometer full-scale ranges.

Values:

enumerator mpu925x_2g

enumerator mpu925x_4g

enumerator mpu925x_8g

enumerator mpu925x_16g

Digital Low Pass Filter

One can enable hardware digital low pass filter. Look datasheet for more info.

void mpu925x_set_accelerometer_dlpf(mpu925x_t *mpu925x, uint8_t a_fchoice, uint8_t dlpf)

Set accelerometer digital low pass filter setting.

Parameters

mpu925x – MPU-925X struct pointer.
a_fchoice – Accelerometer fchoice bit.
dlpf – Digital low pass filter choice.

Offset Cancellation

Offset cancellation consist 2 steps: Getting and setting offset cancellation values. While getting offset cancellation values, sensor must stand still. Also orientation of sensor is very important. Set orientation of sensor with .sensor_settings.orientation variable in mpu925x_t struct.

enum mpu925x_orientation

Orientation of the sensor.

Values:

enumerator mpu925x_x_plus

enumerator mpu925x_x_minus

enumerator mpu925x_y_plus

enumerator mpu925x_y_minus

enumerator mpu925x_z_plus

enumerator mpu925x_z_minus

void mpu925x_get_accelerometer_offset(mpu925x_t *mpu925x, uint16_t sampling_amount, int16_t *offset)

Get accelerometer offset cancellation value.

Parameters

mpu925x – MPU-925X struct pointer.
sampling_amount – Sampling amount for acceleration values.
offset – 3d array which will hold accelerometer offset cancellation values.

void mpu925x_set_accelerometer_offset(mpu925x_t *mpu925x, int16_t *offset)

Set accelerometer offset cancellation value.

Parameters

mpu925x – MPU-925X struct pointer.
offset – 3d array which holds accelerometer offset cancellation values.

One can use these two methods to get and set offset values or call one unified function which does 2 of them at once.

void mpu925x_accelerometer_offset_cancellation(mpu925x_t *mpu925x, uint16_t sampling_amount)

Get and set accelerometer offset cancellation values.

See also

mpu925x_get_accelerometer_offset

See also

mpu925x_set_accelerometer_offset

Parameters

mpu925x – MPU-925X struct pointer.
sampling_amount – Sampling amount for acceleration values.

Example Code

mpu925x.settings.orientation = mpu925x_y_plus; // Depends on how sensor is mounted.
// Sensor must stand still while offset cancellation.
mpu925x_accelerometer_offset_cancellation(&mpu925x, 200);

Gyroscope Advanced Usage

Raw And Translated Data

Raw and translated rotation datas are available. Calling mpu925x_get_rotation function also calls mpu925x_get_rotation_raw function internally. Both functions stores data in given mpu925x_t struct.

void mpu925x_get_rotation(mpu925x_t *mpu925x)

Get rotation in degrees per second.

See also

mpu925x_get_rotation_raw

Parameters: mpu925x – MPU-925X struct pointer.

void mpu925x_get_rotation_raw(mpu925x_t *mpu925x)

Get raw rotation data.

See also

mpu925x_get_rotation

Parameters: mpu925x – MPU-925X struct pointer.

Full-Scale Select

One can set gyroscope full-scale range of 250 dps, 500 dps, 1000 dps and 2000 dps.

void mpu925x_set_gyroscope_scale(mpu925x_t *mpu925x, mpu925x_gyroscope_scale scale)

Set gyroscope full-scale range.

Parameters

mpu925x – MPU-925X struct pointer.
scale – Gyroscope full-scale range to be set.

enum mpu925x_gyroscope_scale

Gyroscope full-scale ranges for gyroscope.

Values:

enumerator mpu925x_250dps

enumerator mpu925x_500dps

enumerator mpu925x_1000dps

enumerator mpu925x_2000dps

Digital Low Pass Filter

One can enable hardware digital low pass filter. Look datasheet for more info.

void mpu925x_set_gyroscope_dlpf(mpu925x_t *mpu925x, uint8_t a_fchoice, uint8_t dlpf)

Set gyroscope digital low pass filter setting.

Parameters

mpu925x – MPU-925X struct pointer.
g_fchoice – Gyroscope f_choice bits.
dlpf – Digital low pass filter setting.

Offset Cancellation

Offset cancellation consist 2 steps: Getting and setting offset cancellation values. While getting offset cancellation values, sensor must stand still.

void mpu925x_get_gyroscope_offset(mpu925x_t *mpu925x, uint16_t sampling_amount, int16_t *offset)

Get gyroscope offset cancellation values.

See also

mpu925x_set_gyroscope_offset

Parameters

mpu925x – MPU-925X struct pointer.
sampling_amount – Sampling amount for rotation values.
offset – 3d array which holds gyroscope offset cancellation values.

void mpu925x_set_gyroscope_offset(mpu925x_t *mpu925x, int16_t *offset)

Set gyroscope offset cancellation values.

See also

mpu925x_get_gyroscope_offset

Parameters

mpu925x – MPU-925X struct pointer.
offset – 3d array which holds gyroscope offset cancellation values.

One can use these two methods to get and set offset values or call one unified function which does 2 of them at once.

void mpu925x_gyroscope_offset_cancellation(mpu925x_t *mpu925x, uint16_t sampling_amount)

Get and set gyroscope offset cancellation values.

See also

mpu925x_get_gyroscope_offset

See also

mpu925x_set_gyroscope_offset

Parameters

mpu925x – MPU-925X struct pointer.
sampling_amount – Sampling amount for rotation values.

Magnetometer Advanced Usage

Raw And Translated Data

Raw and translated magnetic field datas are available. Calling mpu925x_get_magnetic_field function also calls mpu925x_get_magnetic_field_raw function internally. Both functions stores data in given mpu925x_t struct.

void mpu925x_get_magnetic_field(mpu925x_t *mpu925x)

Get magnetic field in micro Gauss.

Parameters: mpu925x – MPU-925X struct pointer.

void mpu925x_get_magnetic_field_raw(mpu925x_t *mpu925x)

Get raw magnetic field data.

Parameters: mpu925x – MPU-925X struct pointer.

Measurement Mode

Operation mode is configurable. See AK8963’s datasheet for more info.

Warning

Other than continuous_measurement_mode_1 and continuous_measurement_mode_2, operating modes are not tested. Wait for full version of this driver to use them properly.

void mpu925x_set_magnetometer_measurement_mode(mpu925x_t *mpu925x, mpu925x_magnetometer_measurement_mode measurement_mode)

Set magnetometer measurement mode.

See also

mpu925x_magnetometer_measurement_mode

Parameters

mpu925x – MPU-925X struct pointer.
measurement_mode – Measurement mode for magnetometer to be set.

enum mpu925x_magnetometer_measurement_mode

Measurement modes for AK8963.

Values:

enumerator mpu925x_power_down_mode

enumerator mpu925x_single_measurement_mode

enumerator mpu925x_continuous_measurement_mode_1

enumerator mpu925x_continuous_measurement_mode_2

enumerator mpu925x_external_trigger_measurement_mode

enumerator mpu925x_self_test_mode

enumerator mpu925x_fuse_rom_access_mode

Bit Mode

Bit mode is configurable. See AK8963’s datasheet for more info.

void mpu925x_set_magnetometer_bit_mode(mpu925x_t *mpu925x, mpu925x_magnetometer_bit_mode bit_mode)

Set magnetometer bit mode.

See also

mpu925x_magnetometer_bit_mode

Parameters

mpu925x – MPU-925X struct pointer.
bit_mode – Bit mode for magnetometer to be set.

enum mpu925x_magnetometer_bit_mode

Bit modes for AK8963.

Values:

enumerator mpu925x_14_bit

enumerator mpu925x_16_bit

Extra Modules

Simple AHRS

Simple attitude and heading reference system module can return pitch and roll angles using acceleration value. Include mpu925x_simple_ahrs.h in desired source file and compile mpu925x_simple_ahrs.c source file with target program.

Example Code

#include "mpu925x.h"
#include "mpu925x_simple_ahrs.h"

// Create struct instances.
mpu925x_t mpu925x;
mpu925x_simple_ahrs ahrs;

// Initialize driver.
mpu925x_init(&mpu925x, 0);

// Get values.
mpu925x_get_acceleration(&mpu925x);
mpu925x_get_simple_ahrs(&mpu925x, &ahrs);

printf("Pitch: %f, Roll: %f\n", ahrs.pitch, ahrs.roll);

API Reference

Simple AHRS header file for MPU-925X driver.

Author
Ceyhun Şen

Typedefs

typedef struct mpu925x_simple_ahrs mpu925x_simple_ahrs

Pitch and roll angles for simple AHRS.

Functions

void mpu925x_get_simple_ahrs(mpu925x_t *mpu925x, mpu925x_simple_ahrs *ahrs)

Get pitch and roll angles.

Parameters

mpu925x – MPU-925X struct pointer.

ahrs – Simple AHRS struct pointer.

struct mpu925x_simple_ahrs

#include <mpu925x_simple_ahrs.h>

Pitch and roll angles for simple AHRS.

Public Members

float pitch

float roll

project

mpu925x-driver

API Reference

Header file for MPU-925X driver.

Author: Ceyhun Şen

Typedefs

typedef enum mpu925x_clock mpu925x_clock

typedef enum mpu925x_orientation mpu925x_orientation

typedef enum mpu925x_accelerometer_scale mpu925x_accelerometer_scale

typedef enum mpu925x_gyroscope_scale mpu925x_gyroscope_scale

typedef enum mpu925x_magnetometer_measurement_mode mpu925x_magnetometer_measurement_mode

typedef enum mpu925x_magnetometer_bit_mode mpu925x_magnetometer_bit_mode

typedef struct mpu925x_t mpu925x_t

Enums

enum mpu925x_clock

Clock settings for MPU-925X.

Values:

enumerator mpu925x_internal_20_hz_clock

enumerator mpu925x_auto_select_pll

enum mpu925x_orientation

Orientation of the sensor.

Values:

enumerator mpu925x_x_plus

enumerator mpu925x_x_minus

enumerator mpu925x_y_plus

enumerator mpu925x_y_minus

enumerator mpu925x_z_plus

enumerator mpu925x_z_minus

enum mpu925x_accelerometer_scale

Accelerometer full-scale ranges.

Values:

enumerator mpu925x_2g

enumerator mpu925x_4g

enumerator mpu925x_8g

enumerator mpu925x_16g

enum mpu925x_gyroscope_scale

Gyroscope full-scale ranges for gyroscope.

Values:

enumerator mpu925x_250dps

enumerator mpu925x_500dps

enumerator mpu925x_1000dps

enumerator mpu925x_2000dps

enum mpu925x_magnetometer_measurement_mode

Measurement modes for AK8963.

Values:

enumerator mpu925x_power_down_mode

enumerator mpu925x_single_measurement_mode

enumerator mpu925x_continuous_measurement_mode_1

enumerator mpu925x_continuous_measurement_mode_2

enumerator mpu925x_external_trigger_measurement_mode

enumerator mpu925x_self_test_mode

enumerator mpu925x_fuse_rom_access_mode

enum mpu925x_magnetometer_bit_mode

Bit modes for AK8963.

Values:

enumerator mpu925x_14_bit

enumerator mpu925x_16_bit

Functions

uint8_t mpu925x_init(mpu925x_t *mpu925x, uint8_t ad0)

Initialize MPU-925X sensor.

Parameters

mpu925x – MPU-925X struct pointer.
ad0 – Last bit of the slave address (depends on ad0 pin connection).

Returns

0 on success, 1 on failure on mpu925x, 2 on failure on AK8963.

void mpu925x_get_all_raw(mpu925x_t *mpu925x)

Get all raw sensor data at once.

Parameters: mpu925x – MPU-925X struct pointer.

void mpu925x_get_all(mpu925x_t *mpu925x)

Get all sensor data at once.

Parameters: mpu925x – MPU-925X struct pointer.

void mpu925x_get_acceleration_raw(mpu925x_t *mpu925x)

Get raw acceleration data.

See also

mpu925x_get_acceleration

Parameters: mpu925x – MPU-925X struct pointer.

void mpu925x_get_acceleration(mpu925x_t *mpu925x)

Get acceleration in G’s.

See also

mpu925x_get_acceleration_raw

Parameters: mpu925x – MPU-925X struct pointer.

void mpu925x_get_rotation_raw(mpu925x_t *mpu925x)

Get raw rotation data.

See also

mpu925x_get_rotation

Parameters: mpu925x – MPU-925X struct pointer.

void mpu925x_get_rotation(mpu925x_t *mpu925x)

Get rotation in degrees per second.

See also

mpu925x_get_rotation_raw

Parameters: mpu925x – MPU-925X struct pointer.

void mpu925x_get_magnetic_field_raw(mpu925x_t *mpu925x)

Get raw magnetic field data.

Parameters: mpu925x – MPU-925X struct pointer.

void mpu925x_get_magnetic_field(mpu925x_t *mpu925x)

Get magnetic field in micro Gauss.

Parameters: mpu925x – MPU-925X struct pointer.

void mpu925x_get_temperature_raw(mpu925x_t *mpu925x)

Get raw temperature data.

Parameters: mpu925x – MPU-925X struct pointer.

void mpu925x_get_temperature(mpu925x_t *mpu925x)

Get temperature in celsius degree.

Parameters: mpu925x – MPU-925X struct pointer.

void mpu925x_set_sample_rate_divider(mpu925x_t *mpu925x, uint8_t sample_rate_divider)

Set sample rate divider.

Parameters

mpu925x – MPU-925X struct pointer.
sample_rate_divider – Sample rate divider sentence.

void mpu925x_set_clock_source(mpu925x_t *mpu925x, mpu925x_clock clock)

Set clock source.

See also

mpu925x_clock

Parameters

mpu925x – MPU-925X struct pointer.
clock – Clock select option.

void mpu925x_set_accelerometer_scale(mpu925x_t *mpu925x, mpu925x_accelerometer_scale scale)

Set accelerometer full-scale range.

Parameters

mpu925x – MPU-925X struct pointer.
scale – Accelerometer full-scale range to be set.

void mpu925x_set_accelerometer_dlpf(mpu925x_t *mpu925x, uint8_t a_fchoice, uint8_t dlpf)

Set accelerometer digital low pass filter setting.

Parameters

mpu925x – MPU-925X struct pointer.
a_fchoice – Accelerometer fchoice bit.
dlpf – Digital low pass filter choice.

void mpu925x_accelerometer_offset_cancellation(mpu925x_t *mpu925x, uint16_t sampling_amount)

Get and set accelerometer offset cancellation values.

See also

mpu925x_get_accelerometer_offset

See also

mpu925x_set_accelerometer_offset

Parameters

mpu925x – MPU-925X struct pointer.
sampling_amount – Sampling amount for acceleration values.

void mpu925x_get_accelerometer_offset(mpu925x_t *mpu925x, uint16_t sampling_amount, int16_t *offset)

Get accelerometer offset cancellation value.

Parameters

mpu925x – MPU-925X struct pointer.
sampling_amount – Sampling amount for acceleration values.
offset – 3d array which will hold accelerometer offset cancellation values.

void mpu925x_set_accelerometer_offset(mpu925x_t *mpu925x, int16_t *offset)

Set accelerometer offset cancellation value.

Parameters

mpu925x – MPU-925X struct pointer.
offset – 3d array which holds accelerometer offset cancellation values.

void mpu925x_set_gyroscope_scale(mpu925x_t *mpu925x, mpu925x_gyroscope_scale scale)

Set gyroscope full-scale range.

Parameters

mpu925x – MPU-925X struct pointer.
scale – Gyroscope full-scale range to be set.

void mpu925x_set_gyroscope_dlpf(mpu925x_t *mpu925x, uint8_t a_fchoice, uint8_t dlpf)

Set gyroscope digital low pass filter setting.

Parameters

mpu925x – MPU-925X struct pointer.
g_fchoice – Gyroscope f_choice bits.
dlpf – Digital low pass filter setting.

void mpu925x_gyroscope_offset_cancellation(mpu925x_t *mpu925x, uint16_t sampling_amount)

Get and set gyroscope offset cancellation values.

See also

mpu925x_get_gyroscope_offset

See also

mpu925x_set_gyroscope_offset

Parameters

mpu925x – MPU-925X struct pointer.
sampling_amount – Sampling amount for rotation values.

void mpu925x_get_gyroscope_offset(mpu925x_t *mpu925x, uint16_t sampling_amount, int16_t *offset)

Get gyroscope offset cancellation values.

See also

mpu925x_set_gyroscope_offset

Parameters

mpu925x – MPU-925X struct pointer.
sampling_amount – Sampling amount for rotation values.
offset – 3d array which holds gyroscope offset cancellation values.

void mpu925x_set_gyroscope_offset(mpu925x_t *mpu925x, int16_t *offset)

Set gyroscope offset cancellation values.

See also

mpu925x_get_gyroscope_offset

Parameters

mpu925x – MPU-925X struct pointer.
offset – 3d array which holds gyroscope offset cancellation values.

void mpu925x_set_magnetometer_measurement_mode(mpu925x_t *mpu925x, mpu925x_magnetometer_measurement_mode measurement_mode)

Set magnetometer measurement mode.

See also

mpu925x_magnetometer_measurement_mode

Parameters

mpu925x – MPU-925X struct pointer.
measurement_mode – Measurement mode for magnetometer to be set.

void mpu925x_set_magnetometer_bit_mode(mpu925x_t *mpu925x, mpu925x_magnetometer_bit_mode bit_mode)

Set magnetometer bit mode.

See also

mpu925x_magnetometer_bit_mode

Parameters

mpu925x – MPU-925X struct pointer.
bit_mode – Bit mode for magnetometer to be set.

struct mpu925x_t

#include <mpu925x.h>

Main struct for MPU-925X driver.

This structs includes sensor data, driver settings and master specific handle, bus and delay function pointers.

Public Members

struct mpu925x_t::sensor_data sensor_data

struct mpu925x_t::settings settings

struct mpu925x_t::master_specific master_specific

struct master_specific

#include <mpu925x.h>

Holds master specific pointers.

Public Members

uint8_t (*bus_read)(struct mpu925x_t *mpu925x, uint8_t slave_address, uint8_t reg, uint8_t *buffer, uint8_t size)

uint8_t (*bus_write)(struct mpu925x_t *mpu925x, uint8_t slave_address, uint8_t reg, uint8_t *buffer, uint8_t size)

void (*delay_ms)(struct mpu925x_t *mpu925x, uint32_t delay)

void *bus_handle

struct sensor_data

#include <mpu925x.h>

Holds sensor data.

Public Members

int16_t acceleration_raw[3]

int16_t rotation_raw[3]

int16_t magnet_raw[3]

int16_t temperature_raw

float acceleration[3]

float rotation[3]

float magnetic_field[3]

float temperature

struct settings

#include <mpu925x.h>

Holds sensor settings.

Public Members

mpu925x_orientation orientation

mpu925x_accelerometer_scale accelerometer_scale

mpu925x_gyroscope_scale gyroscope_scale

mpu925x_magnetometer_measurement_mode measurement_mode

mpu925x_magnetometer_bit_mode bit_mode

float acceleration_lsb

float gyroscope_lsb

float magnetometer_lsb

float temperature_lsb

float magnetometer_coefficient[3]

uint8_t address

License

This project is licensed under MIT license.

MIT License

Copyright (c) 2022 Ceyhun Şen

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
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copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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SOFTWARE.