This library implements drivers for IMUs (Inertial Management Units), that is combined gyroscopes and accelerometers.
The following IMUs are currently implemented:
| IMU | ID | SPI Build Flag |
|---|---|---|
| Bosch BMI270 | BMI270 | USE_IMU_BMI270_SPI |
| CEVA BNO085 | BNO085 | USE_IMU_BNO085_SPI |
| ST LSM6DS3TR-C | LSM6DS3TR_C | USE_IMU_LSM6DS3TR_C_SPI |
| ST ISM330DHCX | ISM330DHCX | USE_IMU_ISM330DHCX_SPI |
| ST LSM6DSOX | LSM6DSOX | USE_IMU_LSM6DSOX_SPI |
| InvenSense MPU-6886 | MPU6886 | USE_IMU_MPU6886_SPI |
The LSM6DS3TR-C, ISM330DHCX, and LSM6DSOX are broadly compatible and share the same driver.
By default the drivers are configured to us I2C. To use SPI, define the relevant SPI build flag for the IMU. This can be done in the build_flags section of platformio.ini.
The Arduino Framework and the Raspberry Pi Pico SDK Framework are supported.
This library uses the VectorQuaternionMatrix library
for its xyz_t(3D vector) and Quaternion classes.
BUS_SPI and BUS_I2C are statically (build-time) polymorphic, not dynamically (run-time) polymorphic.
They have functions that have the same names and signatures, but these functions are not virtual.
This is deliberate.
This means the SPI and I2C read and write functions can be called directly, rather than indirectly via a virtual function pointer.
Some of these functions are short enough that they may be inlined. So in some cases an indirect function call is replaced by an
inlined function. This is important because many of these functions are highly time critical.
It does result in an unconventional class tree: each concrete IMU class has two pointers to its bus: a pointer to BUS_BASE in IMU_BASE
and a reference to either BUS_I2C or BUS_SPI in the class itself.
IMU_BNO085 is shown using I2C_BUS. It can be configured by a build flag to use SPI_BUS.
IMU_BMI270, IMU_LSM6DS3TR_C, and IMU_ICM426xx are shown using SPI_BUS. They can be configured by build flags to use I2C_BUS.
classDiagram
class BUS_BASE {
_deviceRegister uint8_t
_readBuf uint8_t*
_readLength size_t
WAIT_DATA_READY() int32_t
WAIT_DATA_READY(uint32_t ticksToWait) int32_t
SIGNAL_DATA_READY_FROM_ISR()
}
IMU_Base <|-- IMU_M5_UNIFIED
class IMU_M5_UNIFIED {
readGyroRaw() xyz_int32_t override
readAccRaw() xyz_int32_t override
readGyroRPS() xyz_t override
readGyroDPS() xyz_t override
readAcc() xyz_t override
readAccGyroRPS() accGyroRPS_t override
}
IMU_M5_UNIFIED *-- BUS_I2C
IMU_Base <|-- IMU_MPU6886
class IMU_MPU6886 {
setInterruptDriven() override
setGyroOffset(const xyz_int32_t& gyroOffset) override
readGyroRaw() xyz_int32_t override
readAccRaw() xyz_int32_t override
readGyroRPS() xyz_t override
readGyroDPS() xyz_t override
readAcc() xyz_t override
readAccGyroRPS() accGyroRPS_t override
getAccGyroRPS() accGyroRPS_t override
}
IMU_MPU6886 *-- BUS_I2C
IMU_Base <|-- IMU_BNO085
class IMU_BNO085 {
readGyroRaw() xyz_int32_t override
readAccRaw() xyz_int32_t override
readGyroRPS() xyz_t override
readOrientation() Quaternion override
}
IMU_BNO085 *-- BUS_I2C
BUS_BASE <|-- BUS_I2C
class BUS_I2C {
_I2C_index i2c_index_e
_pins pins_t
_I2C_address uint8_t
setInterruptDriven()
setDeviceRegister(uint8_t deviceRegister, uint8_t* readBuf, size_t readLength)
readDeviceRegister() bool
readRegister(uint8_t reg) uint8_t
readRegisterWithTimeout(uint8_t reg, uint32_t timeoutMs) uint8_t
readRegister(uint8_t reg, uint8_t* data, size_t length) bool
readBytes(uint8_t* data, size_t length) bool
readBytesWithTimeout(uint8_t* data, size_t length, uint32_t timeoutMs) bool
writeRegister(uint8_t reg, uint8_t data) uint8_t
writeRegister(uint8_t reg, const uint8_t* data, size_t length) uint8_t
writeBytes(const uint8_t* data, size_t length) uint8_t
}
BUS_BASE <|-- BUS_SPI
class BUS_SPI {
_SPI_index SPI_index_e
_pins pins_t
setInterruptDriven()
setDeviceRegister(uint8_t deviceRegister, uint8_t* readBuf, size_t readLength)
readDeviceRegister() bool
readRegister(uint8_t reg) uint8_t
readRegisterWithTimeout(uint8_t reg, uint32_t timeoutMs) uint8_t
readRegister(uint8_t reg, uint8_t* data, size_t length) bool
readBytes(uint8_t* data, size_t length) bool
readBytesWithTimeout(uint8_t* data, size_t length, uint32_t timeoutMs) bool
writeRegister(uint8_t reg, uint8_t data) uint8_t
writeRegister(uint8_t reg, const uint8_t* data, size_t length) uint8_t
writeBytes(const uint8_t* data, size_t length) uint8_t
}
class IMU_Base {
<<abstract>>
_axisOrder axis_order_e
_gyroResolutionRPS float
_gyroResolutionDPS float
_accResolution float
_gyroSampleRateHz uint32_t
_accSampleRateHz uint32_t
_gyroOffset xyz_int32_t
_accOffset xyz_int32_t
WAIT_IMU_DATA_READY() int32_t
WAIT_IMU_DATA_READY(uint32_t ticksToWait) int32_t
readGyroRaw() xyz_int32_t *
readAccRaw() xyz_int32_t *
virtual init()
virtual setInterruptDriven()
virtual getGyroOffset() xyz_int32_t
virtual setGyroOffset()
virtual getAccOffset() xyz_int32_t
virtual setAccOffset()
virtual getAccOneG_Raw() int32_t
virtual readGyroRPS() xyz_t
virtual readGyroDPS() xyz_t
virtual readAcc() xyz_t
virtual readAccGyroRPS() accGyroRPS_t
virtual getAccGyroRPS() accGyroRPS_t
virtual readOrientation() Quaternion
}
IMU_Base *-- BUS_BASE
IMU_Base <|-- IMU_BMI270
class IMU_BMI270 {
setInterruptDriven() override
readGyroRaw() xyz_int32_t override
readAccRaw() xyz_int32_t override
readGyroRPS() xyz_t override
readGyroDPS() xyz_t override
readAcc() xyz_t override
readAccGyroRPS() accGyroRPS_t override
getAccGyroRPS() accGyroRPS_t override
}
IMU_BMI270 *-- BUS_SPI
IMU_Base <|-- IMU_LSM6DS3TR_C
class IMU_LSM6DS3TR_C {
setInterruptDriven() override
readGyroRaw() xyz_int32_t override
readAccRaw() xyz_int32_t override
readAccGyroRPS() accGyroRPS_t override
getAccGyroRPS() accGyroRPS_t override
}
IMU_LSM6DS3TR_C *-- BUS_SPI
IMU_Base <|-- IMU_ICM426xx
class IMU_ICM426xx {
setInterruptDriven() override
readGyroRaw() xyz_int32_t override
readAccRaw() xyz_int32_t override
readGyroRPS() xyz_t override
readGyroDPS() xyz_t override
readAcc() xyz_t override
readAccGyroRPS() accGyroRPS_t override
getAccGyroRPS() accGyroRPS_t override
}
IMU_ICM426xx *-- BUS_SPI