How to Use BNO-055: Examples, Pinouts, and Specs

The BNO-055 is a 9-axis absolute orientation sensor that integrates a 3-axis accelerometer, a 3-axis gyroscope, and a 3-axis magnetometer. Unlike traditional sensors that require external processing, the BNO-055 features an onboard microcontroller that fuses sensor data to provide accurate orientation information in real-time. This makes it an excellent choice for applications requiring precise motion tracking, such as robotics, drones, augmented reality, and wearable devices.

• Robotics for navigation and stabilization
• Drones for flight control and orientation
• Motion tracking in virtual reality (VR) and augmented reality (AR)
• Wearable devices for fitness and health monitoring
• Industrial automation and control systems

The BNO-055 is a highly versatile sensor with the following key specifications:

The BNO-055 has 10 pins, as described in the table below:

The BNO-055 can be easily interfaced with an Arduino UNO using the I²C protocol. Below is a step-by-step guide:

1. Wiring:

   • Connect the VDD pin of the BNO-055 to the 3.3V pin on the Arduino.
   • Connect the GND pin of the BNO-055 to the GND pin on the Arduino.
   • Connect the SDA pin of the BNO-055 to the A4 pin on the Arduino (I²C data line).
   • Connect the SCL pin of the BNO-055 to the A5 pin on the Arduino (I²C clock line).
   • Set the PS0 and PS1 pins to LOW to enable I²C mode.

2. Install Required Libraries:

   • Install the "Adafruit BNO055" library from the Arduino Library Manager.

3. Example Code: Use the following code to read orientation data from the BNO-055:

   #include <Wire.h>
   #include <Adafruit_Sensor.h>
   #include <Adafruit_BNO055.h>
   
   // Create an instance of the BNO055 sensor
   Adafruit_BNO055 bno = Adafruit_BNO055(55);
   
   void setup() {
     Serial.begin(9600);
     // Initialize the BNO055 sensor
     if (!bno.begin()) {
       Serial.println("BNO055 not detected. Check wiring or I2C address!");
       while (1);
     }
     Serial.println("BNO055 initialized successfully!");
     bno.setExtCrystalUse(true); // Use external crystal for better accuracy
   }
   
   void loop() {
     // Get orientation data (Euler angles)
     sensors_event_t event;
     bno.getEvent(&event);
   
     // Print orientation data to the Serial Monitor
     Serial.print("Heading: ");
     Serial.print(event.orientation.x);
     Serial.print("°, Pitch: ");
     Serial.print(event.orientation.y);
     Serial.print("°, Roll: ");
     Serial.print(event.orientation.z);
     Serial.println("°");
   
     delay(100); // Delay for readability
   }
   

• Power Supply: Ensure the BNO-055 is powered with 3.3V. Using 5V may damage the sensor.
• Pull-Up Resistors: If your I²C bus does not have pull-up resistors, add 4.7kΩ resistors between SDA/SCL and VDD.
• External Crystal: Enabling the external crystal improves accuracy and stability.
• Mounting Orientation: Ensure the sensor is mounted correctly to avoid incorrect orientation readings.

1. BNO-055 Not Detected:

   • Cause: Incorrect wiring or I²C address mismatch.
   • Solution: Double-check the connections and ensure the PS0 and PS1 pins are set for I²C mode. Verify the I²C address in the code (default is 0x28).

2. Inaccurate Orientation Data:

   • Cause: Sensor not calibrated.
   • Solution: Perform a full calibration by moving the sensor in all axes. Use the Adafruit library's calibration example for guidance.

3. No Data Output:

   • Cause: Incorrect baud rate or sensor initialization failure.
   • Solution: Ensure the baud rate in the code matches the Serial Monitor. Check for initialization errors in the setup.

4. Random Spikes in Data:

   • Cause: Electrical noise or unstable power supply.
   • Solution: Use decoupling capacitors near the sensor and ensure a stable 3.3V power source.

• Q: Can the BNO-055 be used with a 5V microcontroller?

  • A: Yes, but you must use a logic level shifter for the I²C lines and power the sensor with 3.3V.

• Q: How do I reset the BNO-055?

  • A: Pull the RST pin low for at least 1 ms, then release it.

• Q: What is the maximum cable length for I²C communication?

  • A: The maximum length depends on the pull-up resistor values and the I²C clock speed. For standard setups, keep the cable length under 1 meter.

• Q: Can I use the BNO-055 in SPI mode?

  • A: Yes, the BNO-055 supports SPI communication. Refer to the datasheet for SPI-specific wiring and configuration.

By following this documentation, you can effectively integrate the BNO-055 into your projects and troubleshoot common issues.