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How to use gyroscope

Learn how to use the Codi:bit gyroscope sensor to detect rotation and angular velocity.

Basic Usage​

Initialization​

from codibit import *

# Initialize the gyroscope
gyroscope = Gyroscope()

Reading Individual Axes​

# Read angular velocity for each axis
x = gyroscope.get_x()  # Roll (left-right rotation)
y = gyroscope.get_y()  # Pitch (forward-backward rotation)
z = gyroscope.get_z()  # Yaw (clockwise-counterclockwise rotation)

print(f"Roll: {x}, Pitch: {y}, Yaw: {z}")

Reading All Axes at Once​

# Get all axis values as a tuple
x, y, z = gyroscope.get_values()
print(f"Angular velocity: X={x}, Y={y}, Z={z}")

Getting Rotation Strength​

# Get the magnitude of rotation (overall rotation strength)
strength = gyroscope.get_strength()
print(f"Rotation strength: {strength}")

Practical Examples​

1. Rotation Detection​

Detect when the board is being rotated:

from codibit import *
import time

gyroscope = Gyroscope()

print("Hold the board still, then rotate it...")
print("Press Ctrl+C to stop")

while True:
    strength = gyroscope.get_strength()

    if strength > 100:  # Threshold for rotation detection
        print(f"Rotation detected! Strength: {strength}")
    else:
        print(f"Still. Strength: {strength}")

    time.sleep(0.1)

2. Axis-Specific Rotation Detection​

Detect rotation around specific axes:

from codibit import *
import time

gyroscope = Gyroscope()

print("Rotate the board around different axes...")
print("Press Ctrl+C to stop")

while True:
    x, y, z = gyroscope.get_values()

    # Check each axis for rotation
    if abs(x) > 50:
        direction = "left" if x > 0 else "right"
        print(f"Rolling {direction}: {x}")

    if abs(y) > 50:
        direction = "forward" if y > 0 else "backward"
        print(f"Pitching {direction}: {y}")

    if abs(z) > 50:
        direction = "clockwise" if z > 0 else "counterclockwise"
        print(f"Yawing {direction}: {z}")

    time.sleep(0.1)

Tips and Best Practices​

  1. Calibration: The gyroscope automatically calibrates to zero when stationary. Keep the board still for a few seconds before starting measurements.

  2. Threshold Selection: Choose appropriate thresholds based on your application. Lower thresholds are more sensitive but may trigger on noise.

  3. Sampling Rate: Consider the sampling rate for your application. Higher rates provide more responsive detection but use more processing power.

  4. Noise Filtering: Implement simple noise filtering by averaging multiple samples or using moving averages.

  5. Coordinate System: Remember the coordinate system:

    • X-axis: Roll (left-right rotation)
    • Y-axis: Pitch (forward-backward rotation)
    • Z-axis: Yaw (clockwise-counterclockwise rotation)

  6. Integration: For angle tracking, you'll need to integrate angular velocity over time, but be aware of drift accumulation.

  7. Combined Sensors: For better orientation tracking, combine gyroscope data with accelerometer data using sensor fusion algorithms.

Troubleshooting​

Problem: Gyroscope readings are noisy

  • Solution: Implement averaging or filtering algorithms
  • Solution: Check for vibrations or movement in the environment

Problem: Readings are always zero

  • Solution: Ensure the sensor is properly initialized
  • Solution: Check I2C connections and addresses

Problem: Unexpected readings

  • Solution: Verify the coordinate system matches your expectations
  • Solution: Check for magnetic interference from nearby objects

Problem: Drift in angle calculations

  • Solution: Implement periodic recalibration
  • Solution: Use complementary sensors (accelerometer) for drift correction