# FastIMU

**Repository Path**: piolib/FastIMU

## Basic Information

- **Project Name**: FastIMU
- **Description**: No description available
- **Primary Language**: Unknown
- **License**: MIT
- **Default Branch**: main
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2026-03-02
- **Last Updated**: 2026-03-02

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

# FastIMU
![1](fast.png)

### Supported IMUS: 

* MPU9255 
* MPU9250 
* MPU6886 
* MPU6515 
* MPU6500 
* MPU6050
* ICM20689 
* ICM20690 
* BMI055 
* BMX055 (Magnetometer currently untested)
* BMI160
* LSM6DS3 (And some of it's variants)
* LSM6DSL (currently untested)
* QMI8658

### Supported Magnetometers:
* QMC5883L
* HMC5883L
* AK8975
* AK8963
* AK09918

### Using non default I2C ports:
If you're planning on using an IMU on a non-default I2C port, you can specify the port in the constructor of your IMU, for example:
```c++
ICM20689 IMU1(Wire); 
MPU6500 IMU2(Wire1); 
```
creates two IMU objects, `ICM20689` will be using the I2C port assigned to `Wire` and `MPU6500` will be on the I2C port assigned to `Wire1`.

### Hybrid IMU's:
You can also use Hybrid IMU's, which means you can add any supported magnetometer to any supported IMU by using the `IMU_HYBRID` class as follows:
```c++
IMU_HYBRID<IMU, MAG> IMU(Wire);
```

For example
```c++
IMU_HYBRID<MPU6050, QMC5883L> IMU(Wire);
```

creates a hybrid `MPU6050` and `QMC5883L` IMU object that behaves as a single IMU, that returns accel and gyro values from the `MPU6050` and magnetometer values from the `QMC5883L` respectively

### Planned:
* BNO080 (probably soonish)
* GY-85
* BMM150 
* BNO055 (the one I bought is DOA... might take a bit)
* ICM20948 
* BMI270 (if I can get my hands on one)

### 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 an optional ```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. if no address is provided, the default for the selected IMU will be used.

* ```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.

* ```IMUName``` Returns a string containing the IMU's name.

* ```IMUType``` Returns a string containing the IMU's type.

* ```IMUManufacturer``` Returns a string containing the IMU's manufacturer.


### Supported IMU VR geometries (and their index numbers):

![2](MountIndex.png)

##### TODO: get DMP working for pure quaternion output from invsense IMU's
##### TODO: get FIFO working for all IMU's that have it.
##### TODO: get timestamping working 
##### TODO: get proper matrix magnetometer calibration working instead of the current scalar garbage.