Table of Contents

1. About
2. Getting Started
   • Wiring
   • Adding to Project
3. Example
4. Documentation
5. Program Flowcharts
   • Sending Case
   • Receiving Case
6. Acknowledgements
7. License
8. Contact

About

esp32_BNO08x is a C++ esp-idf v5.x component, intended to serve as a driver for both the BNO080 and BNO085 IMUs.
This library is heavy influenced by the SparkFun BNO080 Arduino Library, it is more or less a port. It supports access to all the same data that the BNO08x provides.
Currently, only SPI is supported, there is no plans to support I2C (esp32 has I2C driver silicone bug, leading to unpredictable behavior).
I may implement UART at some point in the future.

Getting Started

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Wiring

The default wiring is depicted below, it can be changed at driver initialization (see example section).

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Adding to Project

1. Create a "components" directory in the root workspace directory of your esp-idf project if it does not exist already.

   In workspace directory:

   mkdir components

2. Cd into the components directory and clone the esp32_BNO08x repo.

   cd components
   git clone https://github.com/myles-parfeniuk/esp32_BNO08x.git

3. Ensure you clean your esp-idf project before rebuilding.
   Within esp-idf enabled terminal:

    idf.py fullclean

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Example

#include <stdio.h>
#include "BNO08x.hpp"

extern "C" void app_main(void)
{
    BNO08x imu; //create IMU object with default wiring scheme

    //if a custom wiring scheme is desired instead of default:

    /*
    bno08x_config_t imu_config;     //create config struct
    imu_config.io_mosi = GPIO_NUM_X; //assign pin
    imu_config.io_miso = GPIO_NUM_X; //assign pin
    //etc...
    BNO08x imu(imu_config); //pass config to BNO08x constructor
    */
    

    imu.initialize();  //initialize IMU

    //enable gyro & game rotation vector
    imu.enable_game_rotation_vector(100000UL); //100,000us == 100ms report interval
    imu.enable_gyro(150000UL); //150,000us == 150ms report interval 

    while(1)
    {
        //print absolute heading in degrees and angular velocity in Rad/s
        if(imu.data_available())
        {
            ESP_LOGW("Main", "Velocity: x: %.3f y: %.3f z: %.3f", imu.get_gyro_calibrated_velocity_X(), imu.get_gyro_calibrated_velocity_Y(), imu.get_gyro_calibrated_velocity_Z());
            ESP_LOGI("Main", "Euler Angle: x (roll): %.3f y (pitch): %.3f z (yaw): %.3f", imu.get_roll_deg(), imu.get_pitch_deg(), imu.get_yaw_deg());
        }
    }

}

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Documentation

API documentation generated with doxygen can be found in the documentation directory of the master branch.

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Program Flowcharts

The following charts illustrate the program flow this library implements for sending and receiving data from BNO08x.
These are here to aid development for anyone looking to modify, fork, or contribute.

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Receiving Case

This assumes the user as initialized the imu and has sent a command to enable a report (for ex. enable_game_rotation_vector).

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Sending Case

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Acknowledgements

Special thanks to the original creators of the sparkfun BNO080 library. Developing this without a reference would have been much more time consuming.
https://github.com/sparkfun/SparkFun_BNO080_Arduino_Library

Special thanks to Anton Babiy, aka hwBirdy007 for helping with debugging SPI.
https://github.com/hwBirdy007

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License

Distributed under the MIT License. See LICENSE.md for more information.

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Contact

Myles Parfeniuk - [email protected]

Project Link: https://github.com/myles-parfeniuk/esp32_BNO08x.git

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