How to Use Adafruit L3GD20H Triple-Axis Gyro Breakout Board: Examples, Pinouts, and Specs

The Adafruit L3GD20H Triple-Axis Gyro Breakout Board is a compact and versatile sensor designed to measure angular velocity along three perpendicular axes: pitch, roll, and yaw. This makes it an ideal component for applications in robotics, motion sensing, and stabilization systems. The board features the L3GD20H gyroscope chip, which provides high-resolution measurements and is capable of detecting rates with a high degree of accuracy.

• Inertial Measurement Units (IMUs) for orientation tracking
• Motion control systems for robotics
• User input devices (e.g., game controllers, pointing devices)
• Vehicle navigation systems for dead reckoning
• Stabilization systems for drones and other RC vehicles

• Supply Voltage (VDD): 2.4V to 3.6V
• Output Data Rates (ODR): 12.5 Hz to 800 Hz
• Sensitivity: 245/500/2000 dps (degrees per second)
• Communication Interface: I2C/SPI
• Operating Temperature Range: -40°C to +85°C

1. Powering the Board:

   • Connect the VIN pin to a 2.4V to 3.6V power supply.
   • Connect the GND pin to the ground of your power supply.

2. I2C Communication:

   • Connect the SCL pin to the I2C clock line of your microcontroller.
   • Connect the SDA pin to the I2C data line of your microcontroller.
   • If using multiple I2C devices, ensure each device has a unique address by setting the SA0 pin accordingly.

3. SPI Communication (Optional):

   • Connect the SCL/SPC to the SPI clock line of your microcontroller.
   • Connect the SDA/SPI to the SPI MOSI line of your microcontroller.
   • Connect the SDO to the SPI MISO line of your microcontroller.
   • Control the CS pin to enable and disable the device on the SPI bus.

• Ensure that the power supply is within the specified voltage range to prevent damage.
• Use pull-up resistors on the I2C lines if they are not provided by the microcontroller.
• When using SPI, ensure that the CS pin is only active for the L3GD20H to avoid bus contention.
• Place the gyro in a location with minimal vibration and temperature fluctuations for best performance.

#include <Wire.h>
#include <Adafruit_Sensor.h>
#include <Adafruit_L3GD20_U.h>

Adafruit_L3GD20_Unified gyro = Adafruit_L3GD20_Unified(20);

void setup(void) {
  Serial.begin(9600);
  Serial.println("Gyroscope Test"); Serial.println("");
  
  /* Initialize the sensor */
  if(!gyro.begin())
  {
    /* There was a problem detecting the L3GD20 ... check your connections */
    Serial.println("Ooops, no L3GD20 detected ... Check your wiring!");
    while(1);
  }
}

void loop(void) {
  /* Get a new sensor event */
  sensors_event_t event;
  gyro.getEvent(&event);
 
  /* Display the results (angular velocity is measured in degrees per second) */
  Serial.print("X: "); Serial.print(event.gyro.x); Serial.print(" ");
  Serial.print("Y: "); Serial.print(event.gyro.y); Serial.print(" ");
  Serial.print("Z: "); Serial.print(event.gyro.z); Serial.print(" ");
  Serial.println("deg/s");
  
  /* Delay a bit to keep serial output from being too crazy */
  delay(500);
}

This example initializes the L3GD20H sensor and continuously reads the angular velocity in degrees per second from the X, Y, and Z axes, outputting the results to the serial monitor.

• Sensor not detected: Ensure that the wiring is correct and that the power supply is within the specified range.
• Inaccurate readings: Verify that the sensor is placed in a stable environment and recalibrate if necessary.
• I2C/SPI communication failure: Check the pull-up resistors on the I2C lines or the CS line control for SPI.

• Double-check all connections and solder joints.
• Use the I2C scanner sketch to confirm the device address.
• Ensure that the microcontroller libraries are up to date.
• Consult the Adafruit L3GD20H datasheet for detailed operational characteristics.

Q: Can the L3GD20H be used with a 5V microcontroller? A: Yes, but ensure that the VIN pin is connected to a 3.3V supply, and use logic level converters for I2C/SPI lines if necessary.

Q: How can I change the sensitivity of the sensor? A: The sensitivity can be adjusted through software using the provided library functions.

Q: What is the default I2C address of the L3GD20H? A: The default I2C address is 0x6B when SA0 is high and 0x6A when SA0 is low.

Q: How do I calibrate the gyroscope? A: Calibration involves taking multiple readings at a known stationary state and averaging them to determine an offset. This offset is then subtracted from subsequent readings.