How to Use BNO055: Examples, Pinouts, and Specs

The BNO055 is a sophisticated 9-axis Absolute Orientation Sensor that combines a triaxial 16-bit gyroscope, a triaxial 14-bit accelerometer, and a triaxial geomagnetic sensor along with a 32-bit microcontroller running Bosch Sensortec sensor fusion software. This sensor is ideal for applications that require accurate orientation data such as robotics, augmented reality, gaming, personal navigation, and fitness tracking.

• Robotics: for balancing and navigational purposes.
• Virtual and Augmented Reality: for head tracking to provide immersive experiences.
• Wearable Devices: for activity recognition and step counting.
• Drones: for flight control and stabilization.
• Smartphones and Tablets: for screen orientation and motion detection.

• Operating Voltage: 3.3V to 5V
• Interface: I2C (up to 400kHz) and UART
• Operating Temperature Range: -40°C to +85°C
• Rotation Vector Output: 360°
• Heading Accuracy: 1°
• Angular Rate Resolution: 14 bits

1. Powering the Sensor: Connect the VDD pin to a 3.3V or 5V power supply and the GND pin to the ground.
2. I2C Communication: Connect the SDA and SCL pins to the corresponding SDA and SCL pins on your microcontroller (e.g., Arduino UNO).
3. Address Selection: The ADR pin can be used to change the I2C address if multiple sensors are used on the same I2C bus.
4. Interrupts: The INT pin can be connected to an external interrupt pin on your microcontroller to handle sensor events.

• Ensure that the power supply is within the specified range to prevent damage.
• Use pull-up resistors on the I2C lines if they are not already present on your microcontroller board.
• When using multiple BNO055 sensors on the same I2C bus, make sure to set unique addresses for each sensor.
• For optimal performance, calibrate the sensor according to the manufacturer's instructions.

#include <Wire.h>
#include <Adafruit_Sensor.h>
#include <Adafruit_BNO055.h>

// Check the I2C address in the datasheet and update if necessary
#define BNO055_ADDRESS (0x28)

Adafruit_BNO055 bno = Adafruit_BNO055(55, BNO055_ADDRESS);

void setup() {
  Serial.begin(9600);
  if (!bno.begin()) {
    Serial.println("No BNO055 detected. Check wiring or I2C address.");
    while (1);
  }
  bno.setExtCrystalUse(true);
}

void loop() {
  // Get orientation data
  imu::Vector<3> euler = bno.getVector(Adafruit_BNO055::VECTOR_EULER);
  
  // Output the orientation data
  Serial.print("X: ");
  Serial.print(euler.x());
  Serial.print(" Y: ");
  Serial.print(euler.y());
  Serial.print(" Z: ");
  Serial.println(euler.z());
  
  delay(100);
}

• Sensor Not Detected: Ensure that the wiring is correct and the sensor is properly powered.
• Inaccurate Readings: Calibrate the sensor as per the datasheet instructions.
• I2C Communication Errors: Check for proper pull-up resistors and that the I2C address is correctly set.

• Power Cycle the Sensor: Sometimes simply resetting the power can resolve issues.
• Check Solder Joints: Poor soldering can lead to intermittent connections.
• Use the Interrupt Pin: The INT pin can help manage sensor events and reduce the need for constant polling.

Q: Can the BNO055 run on 5V systems? A: Yes, the BNO055 can operate on both 3.3V and 5V systems.

Q: How do I calibrate the BNO055? A: Follow the calibration procedure outlined in the datasheet, which typically involves moving the sensor through various positions.

Q: What is the default I2C address of the BNO055? A: The default I2C address is 0x28 (or 0x29 if the ADR pin is high).

Q: Can I use the BNO055 with an Arduino UNO? A: Yes, the BNO055 can be easily interfaced with an Arduino UNO using the I2C protocol.

This documentation provides a comprehensive guide to the BNO055 Absolute Orientation Sensor, ensuring users can effectively integrate and utilize this component in their projects.