Overview

The L3GD20H is a 3-axis digital angular rate sensor (gyroscope) manufactured by STMicroelectronics. It measures rotational angular velocity around the X, Y, and Z axes with user-selectable full-scale ranges of $\pm 245\text{ dps}$, $\pm 500\text{ dps}$, and $\pm 2000\text{ dps}$ (degrees per second).

Housed in a compact 16-pin $3 \times 3\text{ mm}$ LGA package, the L3GD20H incorporates an internal 16-bit ADC, configurable low-pass and high-pass digital filters, a 32-level FIFO buffer, an embedded temperature sensor, and dual programmable interrupt generators. It is used in dead-reckoning navigation, optical image stabilization, RC quadcopter flight stabilization, and gaming motion controllers.

Quick reference

Pinout

Breakout modules expose an 8-pin or 9-pin 0.1" (2.54 mm) header:

Specifications

Register map

Wiring

Example

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

Adafruit_L3GD20_Unified gyro = Adafruit_L3GD20_Unified(20);

void setup() {
  Serial.begin(115200);
  Serial.println("L3GD20H Gyroscope Test");

  /* Enable auto-ranging */
  gyro.enableAutoRange(true);

  /* Initialize the sensor */
  if (!gyro.begin()) {
    Serial.println("Could not find L3GD20H! Check wiring.");
    while (1);
  }
  Serial.println("L3GD20H initialized.");
}

void loop() {
  sensors_event_t event;
  gyro.getEvent(&event);

  Serial.print("X: "); Serial.print(event.gyro.x); Serial.print(" rad/s  ");
  Serial.print("Y: "); Serial.print(event.gyro.y); Serial.print(" rad/s  ");
  Serial.print("Z: "); Serial.print(event.gyro.z); Serial.println(" rad/s");

  delay(200);
}

Common mistakes

• Leaving CS floating on $I^2C$ setups: As with ST accelerometers, leaving CS disconnected allows noise to switch the IC into SPI mode. Tie CS High to $V_{CC}$ for $I^2C$ mode.
• Assuming zero-rate output is 0 dps: All mechanical MEMS gyroscopes exhibit static zero-rate offset drift. Application code must perform a 500-sample calibration at startup while stationary to subtract DC bias offsets from X, Y, and Z axes.
• WHO_AM_I register mismatch: Older L3GD20 chips return 0xD4, whereas newer L3GD20H chips return 0xD7. Ensure your library supports 0xD7.

Notes

• L3GD20 vs L3GD20H: The L3GD20H reduces power consumption, adds a 32-level FIFO buffer, improves zero-rate offset stability, and changes full-scale range from $\pm 250\text{ dps}$ to $\pm 245\text{ dps}$.