7Semi BMI323 Arduino Library

Arduino driver for the Bosch BMI323 6-axis IMU sensor.

The BMI323 is a high-performance inertial measurement unit (IMU) with an accelerometer and gyroscope, supporting both I²C and SPI interfaces. It is suitable for applications like motion tracking, robotics, wearable devices, and industrial sensing.

This library provides a clean and efficient interface for configuring the sensor and reading motion data in g (acceleration) and degrees per second (dps).

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Features

• 3-axis accelerometer (X, Y, Z)
• 3-axis gyroscope (X, Y, Z)
• Raw and scaled data reading (g / dps)
• FIFO support (high-speed buffered data)
• Interrupt support (INT1 / INT2)
• Sensor time support
• Temperature measurement
• Gyroscope self-calibration
• Accelerometer FOC calibration
• I2C and SPI communication
• ESP32 custom I2C/SPI pin support

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Supported Platforms

• Arduino UNO / Mega
• ESP32
• Any board supporting Wire (I²C) or SPI

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Hardware

Supported sensor:

7Semi 6-Axis IMU Breakout - BMI323

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Connection

The BMI323 supports both I²C and SPI communication.

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I²C Connection

BMI323 Pin	MCU Pin	Description
VCC	3.3V	Sensor power
GND	GND	Ground
SDA	SDA	I²C data
SCL	SCL	I²C clock

I²C Notes

Default sensor address: 0x68

Recommended I²C speed: 100kHz - 400kHz

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SPI Connection

BMI323 Pin	MCU Pin
VCC	3.3V
GND	GND
SCK	SCK
MISO	MISO
MOSI	MOSI
CS	Any GPIO

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Installation

Arduino Library Manager

1. Open Arduino IDE
2. Go to Library Manager
3. Search for 7Semi BMI323
4. Click Install

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Manual Installation

1. Download this repository as ZIP
2. Arduino IDE → Sketch → Include Library → Add .ZIP Library

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Example

##include <7Semi_BMI323.h>

BMI323_7Semi imu;

void setup()
{
Serial.begin(115200);

if(!imu.beginI2C(0x68))
{
Serial.println("BMI323 not detected");
while(1);
}
}

void loop()
{
float ax, ay, az;
float gx, gy, gz;

if(imu.readAccel(ax, ay, az))
{
Serial.print("ACC: ");
Serial.print(ax);
Serial.print(", ");
Serial.print(ay);
Serial.print(", ");
Serial.println(az);
}

if(imu.readGyro(gx, gy, gz))
{
Serial.print("GYR: ");
Serial.print(gx);
Serial.print(", ");
Serial.print(gy);
Serial.print(", ");
Serial.println(gz);
}

delay(500);
}

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Library Overview

Reading Accelerometer (g)

float x, y, z;

imu.readAccel(x, y, z);

Returns acceleration in g units.

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Reading Gyroscope (dps)

float x,y,z;

imu.readGyro(x,y,z);

Returns angular velocity in degrees per second (dps).

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Reading Raw Data

int16_t ax, ay, az;
int16_t gx, gy, gz;

imu.readAccelRaw(ax, ay, az);
imu.readGyroRaw(gx, gy, gz);

Returns raw sensor values.

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Sensor Configuration

Accelerometer

imu.setAccelConfig(
BMI3_ACC_ODR_100HZ,
BMI3_ACC_BW_ODR_QUARTER,
BMI3_ACC_MODE_NORMAL,
BMI3_ACC_RANGE_2G,
BMI3_ACC_AVG1);

Returns raw sensor values.

Gyroscope

imu.setGyroConfig(
BMI3_GYR_ODR_100HZ,
BMI3_GYR_BW_ODR_QUARTER,
BMI3_GYR_MODE_NORMAL,
BMI3_GYR_RANGE_2000DPS,
BMI3_GYR_AVG1);

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FIFO Usage

Enable FIFO:

imu.setFifoConfig(BMI_FIFO_ALL_EN,true);
imu.setFifoWatermark(200);

Read FIFO:

bmi3_fifo_frame fifo;

fifo.data = buffer;
fifo.length = buffer_size;

imu.getFifoData(fifo);

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Interrupts

Configure interrupt pin:

imu.setInterruptConfig(BMI3_INT1, true, false);
imu.enableInterrupt(BMI3_INT1, true, false);

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Temperature

float temp;

imu.getTemperature(temp);

Returns temperature in °C.

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Calibration

Gyroscope Calibration

imu.calibrateGyro(1, true);

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Accelerometer FOC

imu.calibrateAccelFOC(true, false, false, false);

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Example Applications

Typical applications include:

• Motion tracking
• Robotics and drones
• Gesture detection
• Wearable devices
• Industrial monitoring
• Orientation sensing

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License

MIT License

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Author

7Semi