Jamie Smith / BNO080

Fully featured I2C and SPI driver for CEVA (Hilcrest)'s BNO080 and FSM300 Inertial Measurement Units.

Dependents:   BNO080-Examples BNO080-Examples

BNO080 Driver

by Jamie Smith / USC Rocket Propulsion Lab

After lots of development, we are proud to present our driver for the Hilcrest BNO080 IMU! This driver is inspired by SparkFun and Nathan Seidle's Arduino driver for this chip, but has been substantially rewritten and adapted.

It supports the main features of the chip, such as reading rotation and acceleration data, as well as some of its more esoteric functionality, such as counting steps and detecting whether the device is being hand-held.

Features

  • Support for 15 different data reports from the IMU, from acceleration to rotation to tap detection
  • Support for reading of sensor data, and automatic checking of update rate against allowed values in metadata
  • BNO_DEBUG switch enabling verbose, detailed output about communications with the chip for ease of debugging
  • Ability to tare sensor rotation and set mounting orientation
  • Can operate in several execution modes: polling I2C, polling SPI, and threaded SPI (which handles timing-critical functions in a dedicated thread, and automatically activates when the IMU has data available)
    • Also has experimental support for using asynchronous SPI transactions, allowing other threads to execute while communication with the BNO is occurring. Note that this functionality requires a patch to Mbed OS source code due to Mbed bug #13941
  • Calibration function
  • Reasonable code size for what you get: the library uses about 4K of flash and one instance of the object uses about 1700 bytes of RAM.

Documentation

Full Doxygen documentation is available online here

Example Code

Here's a simple example:

BNO080 Rotation Vector and Acceleration

#include <mbed.h>
#include <BNO080.h>

int main()
{
	Serial pc(USBTX, USBRX);

	// Create IMU, passing in output stream, pins, I2C address, and I2C frequency
	// These pin assignments are specific to my dev setup -- you'll need to change them
	BNO080I2C imu(&pc, p28, p27, p16, p30, 0x4a, 100000); 

	pc.baud(115200);
	pc.printf("============================================================\n");

	// Tell the IMU to report rotation every 100ms and acceleration every 200ms
	imu.enableReport(BNO080::ROTATION, 100);
	imu.enableReport(BNO080::TOTAL_ACCELERATION, 200);

	while (true)
	{
		wait(.001f);
		
		// poll the IMU for new data -- this returns true if any packets were received
		if(imu.updateData())
		{
			// now check for the specific type of data that was received (can be multiple at once)
			if (imu.hasNewData(BNO080::ROTATION))
			{
				// convert quaternion to Euler degrees and print
				pc.printf("IMU Rotation Euler: ");
				TVector3 eulerRadians = imu.rotationVector.euler();
				TVector3 eulerDegrees = eulerRadians * (180.0 / M_PI);
				eulerDegrees.print(pc, true);
				pc.printf("\n");
			}
			if (imu.hasNewData(BNO080::TOTAL_ACCELERATION))
			{
				// print the acceleration vector using its builtin print() method
				pc.printf("IMU Total Acceleration: ");
				imu.totalAcceleration.print(pc, true);
				pc.printf("\n");
			}
		}
	}

}

If you want more, a comprehensive, ready-to-run set of examples is available on my BNO080-Examples repository.

Credits

This driver makes use of a lightweight, public-domain library for vectors and quaternions available here.

Changelog

Version 2.1 (Nov 24 2020)

  • Added BNO080Async, which provides a threaded implementation of the SPI driver. This should help get the best performance and remove annoying timing requirements on the code calling the driver
  • Added experimental USE_ASYNC_SPI option
  • Fixed bug in v2.0 causing calibrations to fail

Version 2.0 (Nov 18 2020)

  • Added SPI support
  • Refactored buffer system so that SPI could be implemented as a subclass. Unfortunately this does substantially increase the memory usage of the driver, but I believe that the benefits are worth it.

Version 1.3 (Jul 21 2020)

  • Fix deprecation warnings and compile errors in Mbed 6
  • Fix compile errors in Arm Compiler (why doesn't it have M_PI????)

Version 1.2 (Jan 30 2020)

  • Removed accidental IRQ change
  • Fixed hard iron offset reading incorrectly due to missing cast

Version 1.1 (Jun 14 2019)

  • Added support for changing permanent orientation
  • Add FRS writing functions
  • Removed some errant printfs

Version 1.0 (Dec 29 2018)

  • Initial Mbed OS release

BNO080Constants.h

Committer:
Jamie Smith
Date:
2020-11-24
Revision:
9:430f5302f9e1
Parent:
8:199c7fad233d

File content as of revision 9:430f5302f9e1:

//
// Constants used in communication with the BNO080
//

#ifndef HAMSTER_BNO080CONSTANTS_H
#define HAMSTER_BNO080CONSTANTS_H


//-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

// Channels
#define CHANNEL_COMMAND 0
#define CHANNEL_EXECUTABLE 1
#define CHANNEL_CONTROL 2
#define CHANNEL_REPORTS 3
#define CHANNEL_WAKE_REPORTS 4
#define CHANNEL_GYRO 5

// Report IDs on the command channel.
// Unlike the other constants, these come from the Sensor Hub Transport Protocol datasheet, section 5.1
#define COMMAND_REPORTID_ADVERTISEMENT 0x0
#define COMMAND_REPORTID_ERRORLIST 0x1

//All the ways we can configure or talk to the BNO080, figure 34, page 36 reference manual
//These are used for low level communication with the sensor, on channel 2
#define SHTP_REPORT_COMMAND_RESPONSE 0xF1
#define SHTP_REPORT_COMMAND_REQUEST 0xF2
#define SHTP_REPORT_FRS_READ_RESPONSE 0xF3
#define SHTP_REPORT_FRS_READ_REQUEST 0xF4
#define SHTP_REPORT_FRS_WRITE_RESPONSE 0xF5
#define SHTP_REPORT_FRS_WRITE_DATA 0xF6
#define SHTP_REPORT_FRS_WRITE_REQUEST 0xF7
#define SHTP_REPORT_PRODUCT_ID_RESPONSE 0xF8
#define SHTP_REPORT_PRODUCT_ID_REQUEST 0xF9
#define SHTP_REPORT_BASE_TIMESTAMP 0xFB
#define SHTP_REPORT_SET_FEATURE_COMMAND 0xFD
#define SHTP_REPORT_GET_FEATURE_RESPONSE 0xFC

//All the different sensors and features we can get reports from
//These are used when enabling a given sensor
#define SENSOR_REPORTID_TIMESTAMP_REBASE 0xFA
#define SENSOR_REPORTID_ACCELEROMETER 0x01
#define SENSOR_REPORTID_GYROSCOPE_CALIBRATED 0x02
#define SENSOR_REPORTID_MAGNETIC_FIELD_CALIBRATED 0x03
#define SENSOR_REPORTID_LINEAR_ACCELERATION 0x04
#define SENSOR_REPORTID_ROTATION_VECTOR 0x05
#define SENSOR_REPORTID_GRAVITY 0x06
#define SENSOR_REPORTID_GAME_ROTATION_VECTOR 0x08
#define SENSOR_REPORTID_GEOMAGNETIC_ROTATION_VECTOR 0x09
#define SENSOR_REPORTID_MAGNETIC_FIELD_UNCALIBRATED 0x0F
#define SENSOR_REPORTID_TAP_DETECTOR 0x10
#define SENSOR_REPORTID_STEP_COUNTER 0x11
#define SENSOR_REPORTID_SIGNIFICANT_MOTION 0x12
#define SENSOR_REPORTID_STABILITY_CLASSIFIER 0x13
#define SENSOR_REPORTID_STEP_DETECTOR 0x18
#define SENSOR_REPORTID_SHAKE_DETECTOR 0x19

// sensor report ID with the largest numeric value
#define MAX_SENSOR_REPORTID SENSOR_REPORTID_SHAKE_DETECTOR

// Q points for various sensor data elements
#define ACCELEROMETER_Q_POINT 8 // for accelerometer based data
#define GYRO_Q_POINT 9 // for gyroscope data
#define MAGNETOMETER_Q_POINT 4 // for magnetometer data
#define ROTATION_Q_POINT 14 // for rotation data
#define ROTATION_ACCURACY_Q_POINT 12 // for rotation accuracy data
#define POWER_Q_POINT 10 // for power information in the metadata
#define ORIENTATION_QUAT_Q_POINT 14 // for the set orientation command
#define FRS_ORIENTATION_Q_POINT 30 // for the sensor orientation FRS record

// Report IDs on the Executable channel
// See Figure 1-27 in the BNO080 datasheet
#define EXECUTABLE_REPORTID_RESET 0x1

//Record IDs from SH-2 figure 28
//These are used to read and set various configuration options
#define FRS_RECORDID_SERIAL_NUMBER 0x4B4B
#define FRS_RECORDID_SYSTEM_ORIENTATION 0x2D3E

//Command IDs from section 6.4, page 42
//These are used to calibrate, initialize, set orientation, tare etc the sensor
#define COMMAND_ERRORS 1
#define COMMAND_COUNTER 2
#define COMMAND_TARE 3
#define COMMAND_INITIALIZE 4
#define COMMAND_SAVE_DCD 6
#define COMMAND_ME_CALIBRATE 7
#define COMMAND_DCD_PERIOD_SAVE 9
#define COMMAND_OSCILLATOR 10
#define COMMAND_CLEAR_DCD 11
#define COMMAND_UNSOLICITED_INITIALIZE 0x84

#define CALIBRATE_ACCEL 0
#define CALIBRATE_GYRO 1
#define CALIBRATE_MAG 2
#define CALIBRATE_PLANAR_ACCEL 3
#define CALIBRATE_ACCEL_GYRO_MAG 4
#define CALIBRATE_STOP 5

// timing for reset
// per my measurement, reset takes about 90ms, so let's take twice that
// By the way, I discovered (by accident) that a symptom of brownout is the chip taking
// a long time to reset.  So if you had to increase this, check that your Vcc is 
// within the allowed range.
#define BNO080_RESET_TIMEOUT 180ms

#endif //HAMSTER_BNO080CONSTANTS_H