Arduino wrapper for the Bosch BMI270 6-axis IMU sensor, designed to simplify integration of accelerometer and gyroscope functionality in embedded and IoT applications.
This library provides a clean abstraction over low-level communication, allowing developers to quickly access motion data with minimal setup using I2C or SPI interfaces.
Supported interfaces: I2C / SPI
| BMI270 Pin | ESP32 Pin | Notes |
|---|---|---|
| VCC | 3.3V | check your board's tolerance |
| GND | GND | Common ground |
| SDA | GPIO 21 | Can be changed |
| SCL | GPIO 22 | Can be changed |
| SDO | LOW | Sets I2C address to 0x68 |
I2C Address:
- 0x68 → SDO = LOW
- 0x69 → SDO = HIGH
I2C Speed:
- Recommended: 400 kHz
- Supported: up to 1 MHz
Important: BMI270 selects SPI or I2C at power-up. To force SPI mode, CS must be LOW during power-up.
ESP32 VSPI Wiring:
| BMI270 Pin | ESP32 Pin | Notes |
|---|---|---|
| CS | GPIO 5 | Must be LOW at boot |
| SCK | GPIO 18 | VSPI clock |
| MISO | GPIO 19 | VSPI MISO |
| MOSI | GPIO 23 | VSPI MOSI |
| VCC | 3.3V | Required |
| GND | GND | Required |
SPI Configuration:
- Mode: SPI MODE 0
- Init speed: ≤ 1 MHz
- Normal speed: ≤ 10 MHz
Output Data Rate (ODR):
- BMI2_ACC_ODR_0_78HZ (ultra low power)
- BMI2_ACC_ODR_12_5HZ
- BMI2_ACC_ODR_25HZ
- BMI2_ACC_ODR_50HZ
- BMI2_ACC_ODR_100HZ ← recommended
- BMI2_ACC_ODR_200HZ
- BMI2_ACC_ODR_400HZ
- BMI2_ACC_ODR_800HZ
- BMI2_ACC_ODR_1600HZ
Measurement Range:
- BMI2_ACC_RANGE_2G ← best resolution
- BMI2_ACC_RANGE_4G
- BMI2_ACC_RANGE_8G
- BMI2_ACC_RANGE_16G (large motion)
Bandwidth (Noise vs Latency):
- BMI2_ACC_OSR4_AVG1 (lowest latency)
- BMI2_ACC_OSR2_AVG2
- BMI2_ACC_NORMAL_AVG4 ← recommended
- BMI2_ACC_CIC_AVG8
- BMI2_ACC_RES_AVG16
- BMI2_ACC_RES_AVG32
- BMI2_ACC_RES_AVG64
- BMI2_ACC_RES_AVG128 (lowest noise)
Output Data Rate (ODR):
- BMI2_GYR_ODR_25HZ
- BMI2_GYR_ODR_50HZ
- BMI2_GYR_ODR_100HZ ← recommended
- BMI2_GYR_ODR_200HZ
- BMI2_GYR_ODR_400HZ
- BMI2_GYR_ODR_800HZ
- BMI2_GYR_ODR_1600HZ
- BMI2_GYR_ODR_3200HZ
Measurement Range (deg/s):
- BMI2_GYR_RANGE_125
- BMI2_GYR_RANGE_250
- BMI2_GYR_RANGE_500
- BMI2_GYR_RANGE_1000
- BMI2_GYR_RANGE_2000 ← fast motion
Bandwidth:
- BMI2_GYR_OSR4_MODE (lowest latency)
- BMI2_GYR_OSR2_MODE
- BMI2_GYR_NORMAL_MODE ← recommended
| Sensor | ODR | Range | Bandwidth |
|---|---|---|---|
| Accelerometer | 100 Hz | ±2G | NORMAL_AVG4 |
| Gyroscope | 100 Hz | ±2000 dps | NORMAL_MODE |
| Sensor | Unit |
|---|---|
| Accelerometer | g |
| Gyroscope | degrees/second (dps) |
| Temperature | °C |
-
Wrong CHIP_ID?
Expected value: 0x24. Check wiring and power. -
SPI not working?
CS must be LOW at power-up. -
No data?
Confirm ODR is enabled and check loop timing.
- FIFO burst reads
- Interrupt-driven data ready
- Low-power mode
- Sensor fusion (external)
- Calibration routines
MIT License – This Arduino/C++ wrapper, examples, and documentation are released under the MIT License.
Bosch Sensortec Driver:
- This library uses the official Bosch Sensortec BMI2/BMI270 C driver, which is copyright © Bosch Sensortec GmbH and licensed under the BSD 3-Clause License.
- Bosch license terms must be retained when redistributing Bosch source/header files.
- This wrapper does not modify or replace Bosch’s license; it only adds Arduino integration.