CodeCell: Reading the Gyroscope

CodeCell includes a built-in BNO085 3-axis gyroscope that measures angular velocity - how fast CodeCell is rotating around each axis. This lets you detect turning, spinning, or orientation changes.

How It Works

The gyroscope measures rotation speed in degrees per second (°/s) along three axes:

• X-axis → Tilt forward/backward
• Y-axis → Tilt left/right
• Z-axis → Twist or spin

You can enable and read gyroscope data using two simple functions:

myCodeCell.Init(MOTION_GYRO);             // Enable gyroscope sensing
myCodeCell.Motion_GyroRead(x, y, z);      // Read angular velocity on all axes

Each reading gives the current rotation speed on the X, Y, and Z axes in °/s.

Example 1 – Read Gyroscope Data

This example prints live angular velocity readings to the Serial Monitor, showing how fast CodeCell is rotating around each axis.

#include <CodeCell.h>

CodeCell myCodeCell;

float x = 0.0, y = 0.0, z = 0.0;

void setup() {
  Serial.begin(115200);
  myCodeCell.Init(MOTION_GYRO);  // Initialize gyroscope
}

void loop() {
  if (myCodeCell.Run(10)) {      // Run at 10 Hz
    myCodeCell.Motion_GyroRead(x, y, z);  // Read gyro data

    Serial.print("Gyro X: "); Serial.print(x);
    Serial.print("  Y: "); Serial.print(y);
    Serial.print("  Z: "); Serial.println(z);
  }
}

What You’ll Notice:

• When still, values are close to 0.
• Tilting forward/backward changes X.
• Tilting left/right changes Y.
• Rotating like a steering wheel changes Z.

Example 2 – Detect Rotation and Change LED Color

This example changes CodeCell’s onboard LED color based on rotation direction, red when turning left, green when turning right.

#include <CodeCell.h>

CodeCell myCodeCell;

float x = 0.0, y = 0.0, z = 0.0;
const float ROTATION_THRESHOLD = 3.0;  // Rotation speed threshold (°/s)

void setup() {
  Serial.begin(115200);
  myCodeCell.Init(MOTION_GYRO);  // Enable gyroscope
}

void loop() {
  if (myCodeCell.Run(10)) {      // Run at 10 Hz
    myCodeCell.Motion_GyroRead(x, y, z);  // Read angular velocity

    Serial.print("Gyro Z: ");
    Serial.println(z);

    if (z > ROTATION_THRESHOLD) {          // Rotating right
      myCodeCell.LED(0, 255, 0);           // Green LED
    } 
    else if (z < -ROTATION_THRESHOLD) {    // Rotating left
      myCodeCell.LED(255, 0, 0);           // Red LED
    } 
    else {
      myCodeCell.LED(0, 0, 0);             // LED off
    }
  }
}

How It Works:

• Z > 3 → Rotating right → LED turns green.
• Z < -3 → Rotating left → LED turns red.

Adjust ROTATION_THRESHOLD to control sensitivity:

• Higher → Detects only fast rotations.
• Lower → Detects even small movements.

Customization Tips

• Try different axes: Visualize pitch (X) or roll (Y) using other LED colors.
• Detect flicks: Use short bursts of rotation for gesture input.
• Combine with other sensors: Merge with accelerometer or magnetometer data for full motion tracking.