FastIMU

Currently supported IMUS:

• MPU9255
• MPU9250
• MPU6886
• MPU6515
• MPU6500
• MPU6050
• ICM20689
• ICM20690
• BMI055
• BMX055 (Magnetometer currently untested)
• BMI160
• LSM6DS3
• LSM6DSL (currently untested)
• QMC5883L
• MPU6050 + QMC5883L (uses type MPU6050_QMC5883L, expects IMU address)

Data types

• AccelData Contains all three axis of Accelerometer data, these are named accelX, accelY and accelZ

• GyroData Contains all three axis of Gyroscope data, these are named gyroX, gyroY and gyroZ

• MagData Contains all three axis of Magnetometer data, these are named magX, magY and magZ

• Quaternion Contains Quaternion data, the components are named qW, qX, qY and qZ

• CalData Contains a boolean component named valid that must be set to true if the data is valid, it contains float array named accelBias for accelerometer biases, one named gyroBias for gyroscope bias, one named magBias for magnetometer biases and one named magScale for magnetometer scaling.

Functions

• init Takes in a calData function and a byte address, this function initializes the IMU, it defaults to the maximum ranges allowed by the IMU. This function will return a 0 if initialization was successful and a negative number if it failed to connect to the IMU.

• update Reads new IMU data if available.

• getAccel Takes in a pointer to AccelData and copies new accelerometer data to it, should be called after update.

• getGyro Takes in a pointer to GyroData and copies new gyroscope data to it, should be called after update.

• getMag Takes in a pointer to MagData and copies new magnetometer data to it, should be called after update. Will only return new magnetometer data if the IMU has a magnetometer.

• getQuat Takes in a pointer to a Quaternion and copies new quaternion data to it, should be called after update. Will only return new Quaternion data if the IMU has a Quaternion output.

• getTemp Returns temperature float data in °C, should be called after update, isn't very accurate.

• setGyroRange Takes in an integer with the dps range wanted, (for example 2000 for ±2000dps), returns 0 if successful, returns -1 if the input range is not valid.

• setAccelRange Takes in an integer with the dps range wanted, (for example 8 for ±8g), returns 0 if successful, returns -1 if the input range is not valid.

• setIMUGeometry Takes in an integer with the wanted geometry index, rotates IMU measurements to match vr headset IMU mount. (see chart below).

• calibrateAccelGyro Takes in a pointer to calibration data and runs a Accelerometer and Gyroscope calibration, storing the new accelerometer and gyroscope calibration data in it. the IMU should be kept completely still and level during this.

• calibrateMag Takes in a pointer to Calibration data and runs a Accelerometer and Gyroscope calibration, storing the new accelerometer and gyroscope calibration data in it. the IMU should be moved in a figure eight pattern while calibrating, calibration takes around 15 seconds.

• hasMagnetometer Returns true if the IMU has a magnetometer.

• hasTemperature Returns true if the IMU has a thermometer.

• hasQuatOutput Returns true if the IMU has a direct quaternion output.

Supported IMU VR geometries (and their index numbers):

TODO: get DMP working for pure quaternion output from invsense IMU's