BNO055 Detailed explanation of pin function specifications and circuit principle instructions

The BNO055 is a Sensor module manufactured by Bosch Sensortec. It is a 9-axis motion sensor that includes a 3D accelerometer, gyroscope, and magnetometer, all in one chip, often used in applications involving motion tracking and orientation sensing.

Here is the detailed breakdown you requested. I'll cover the BNO055's pinout, its pin functions, and then provide a list of FAQ questions and answers.

1. Pinout and Pin Functions

The BNO055 sensor typically comes in a LGA (Land Grid Array) or QFN (Quad Flat No-lead) package. Here’s a typical BNO055 QFN-14 package, which has 14 pins. This number can vary slightly depending on the exact module configuration, but the most common version is the QFN-14.

Pinout Diagram for BNO055 QFN-14 (Pins may vary based on the module)

Pin Number Pin Name Pin Function Description 1 VDD Power Supply (3.3V): Supplies power to the sensor module. Ensure that this pin is connected to 3.3V for correct operation. 2 VDDIO I/O Voltage Supply (3.3V): Provides power for I/O communication, typically connected to a 3.3V supply. 3 SDA Serial Data (I2C): This is the data line for I2C communication. In I2C mode, it transmits the sensor data. 4 SCL Serial Clock (I2C): This is the clock line for I2C communication. It provides the timing signal to synchronize data transfer. 5 INT Interrupt Output: The interrupt signal output for the host processor to receive notifications of important events or errors (like sensor data ready). 6 RST Reset: Resets the sensor. You can use this pin to hard reset the BNO055 when required. 7 nCS Chip Select (SPI): Used in SPI mode to select the BNO055 sensor. It is active low. 8 MISO Master In Slave Out (SPI): In SPI mode, this pin carries the sensor data to the master device (e.g., a microcontroller). 9 MOSI Master Out Slave In (SPI): In SPI mode, this pin carries data from the master to the slave device (BNO055 sensor). 10 SDO SPI Data Output (for SPI): Used as the SPI data output pin. It’s also used in I2C mode for the sensor's address configuration (0x28 or 0x29). 11 GND Ground: Provides the common ground connection for the module. 12 VDD Power Supply (same as Pin 1) 13 N/C No Connection: This pin does not connect to anything internally. It may be left unconnected. 14 N/C No Connection: Same as pin 13, used for packaging and unused for electrical signals.

2. FAQ (Frequently Asked Questions)

Q: What is the BNO055 sensor used for? A: The BNO055 is a 9-axis sensor used for motion sensing and orientation detection. It integrates an accelerometer, gyroscope, and magnetometer, making it suitable for robotics, wearables, and navigation systems. Q: What is the communication protocol of BNO055? A: The BNO055 supports both I2C and SPI communication protocols. You can select the communication protocol via configuration settings. Q: What is the default I2C address for the BNO055 sensor? A: The default I2C address for the BNO055 sensor is 0x28 (7-bit address) for the default configuration. It can be changed via the SDO pin. Q: How can I reset the BNO055 sensor? A: You can reset the sensor by pulling the RST pin low for a brief moment and then releasing it, or by using the software reset command through I2C/SPI communication. Q: How do I interface the BNO055 with an Arduino? A: To interface with Arduino, connect the sensor's SDA and SCL pins to the Arduino's SDA and SCL pins for I2C communication. Use a library such as Adafruit’s BNO055 library to simplify the interaction. Q: What is the power consumption of the BNO055? A: The BNO055 typically consumes 1.6mA in active mode and much less in low-power modes. The power consumption can vary based on the operation mode and usage. Q: Can I use the BNO055 with 5V logic? A: No, the BNO055 operates at 3.3V logic. It is essential to ensure that the supply voltage is 3.3V, and logic level shifting may be required when interfacing with 5V logic systems. Q: What is the function of the INT pin on the BNO055? A: The INT pin is an interrupt output pin. It sends a signal to the host when certain events occur, such as when new sensor data is available. Q: What is the role of the nCS pin in SPI mode? A: The nCS (Chip Select) pin is used to select the BNO055 sensor when communicating via SPI. It is active low, meaning the chip is selected when the pin is pulled low.

Q: Can I use the BNO055 with SPI only, or is I2C necessary?

A: You can use the BNO055 with only SPI or only I2C, depending on your needs. Both communication protocols are supported independently.

Q: What kind of applications can I use the BNO055 in?

A: The BNO055 is used in applications such as robotics, drones, motion-tracking devices, virtual reality systems, wearable electronics, and more.

Q: How do I change the sensor's communication mode (SPI to I2C)?

A: The communication mode can be changed by configuring the SDO pin and setting it to low (I2C mode) or high (SPI mode) before powering up the sensor.

Q: Does the BNO055 come with built-in calibration?

A: Yes, the BNO055 has built-in calibration features for its accelerometer, gyroscope, and magnetometer. It can provide calibrated data out of the box.

Q: What should I do if the BNO055 sensor is not responding?

A: Ensure the sensor is properly powered (3.3V) and connected to the correct I2C/SPI pins. Also, check the RST pin for proper reset and verify the correct communication protocol (I2C or SPI).

Q: Is it possible to stack multiple BNO055 sensors?

A: Yes, you can stack multiple sensors in I2C mode, but you must assign a unique I2C address to each sensor using the SDO pin to avoid address conflicts.

Q: How accurate is the orientation data from BNO055?

A: The BNO055 offers 9-degree-of-freedom data (accelerometer, gyroscope, and magnetometer) with fusion algorithms to provide accurate orientation data. Accuracy can vary depending on calibration.

Q: What is the range of the accelerometer in BNO055?

A: The accelerometer in the BNO055 has a range of ±2g, ±4g, ±8g, and ±16g, which can be selected based on the application's needs.

Q: What is the range of the gyroscope in BNO055?

A: The gyroscope in the BNO055 has selectable ranges of ±125, ±250, ±500, ±1000, and ±2000 degrees per second (dps).

Q: Can the BNO055 be used for indoor navigation?

A: Yes, the BNO055 can be used for indoor navigation by providing orientation and motion tracking data, although external factors like Magnetic interference may affect its accuracy.

Q: How do I handle magnetic interference when using the BNO055?

A: Magnetic interference can affect the magnetometer's accuracy. It is recommended to calibrate the magnetometer regularly and to avoid placing the sensor near strong magnetic fields.

This comprehensive guide should cover the pin functions and FAQs you requested. If you need further details or adjustments, feel free to ask!