Circuit Analysis

Before you layout a circuit, it's generally a good idea to understand what is happening in your schematic.  And before you lay out a schematic, it's generally a good idea to understand what is happening in your block diagram.

Hard Way Hughes"This book is a bit technical.  If you are a beginner, it's okay that you don't understand everything that follows -- your first project will still be successful.  Try to pick up as much as you can, and ask questions in the forums!"

4. IMU Sensor

BNO055 Connections

BNO055 Schematic Block

Basic Function

The BNO055 inertial measurement unit by Bosch has three types of tri-axial sensors: Accelerometer, Gyroscope, and Magnetometer.  To increase accuracy, a 32.768 kHz MEMS oscillator is included and must be enabled via register flags.

Circuit Considerations

Two pull-up resistors attached to nBoot_Load_Pin and nReset set digital inputs and operating mode while a series of capacitors provide decoupling.  Four taps are provided for data bus inspection.

The datasheet notes that the sensor's sensitive magnetometer should be mounted well away from any ferromagnetic materials.  Place this device as far away from the LCD, header pins, badge clips, and batteries as possible.  One other thing -- the sensor package is rather inaccurate before calibration.  Be sure to follow the Bosch calibration guidelines before using your device.