How to Use Adafruit LSM6DS3TR-C + LIS3MDL - Precision 9 DoF IMU - STEMMA QT / Qwiic: Examples, Pinouts, and Specs

The Adafruit LSM6DS3TR-C + LIS3MDL (Part ID: 5543) is a precision 9 Degrees of Freedom (DoF) Inertial Measurement Unit (IMU) designed for accurate motion tracking and orientation sensing. This module combines two powerful sensors: the LSM6DS3TR-C, which integrates a 3-axis accelerometer and a 3-axis gyroscope, and the LIS3MDL, a 3-axis magnetometer. Together, these sensors provide comprehensive motion and orientation data.

This IMU is equipped with STEMMA QT / Qwiic connectors, enabling plug-and-play compatibility with a wide range of development boards and simplifying integration into projects. It is ideal for applications such as robotics, drones, wearable devices, and gaming controllers.

• Manufacturer: Adafruit
• Part ID: 5543
• Sensors:
  • LSM6DS3TR-C: 3-axis accelerometer and 3-axis gyroscope
  • LIS3MDL: 3-axis magnetometer
• Interface: I²C (default) or SPI
• I²C Address:
  • LSM6DS3TR-C: 0x6A (default) or 0x6B
  • LIS3MDL: 0x1C, 0x1E, 0x1D, or 0x1F (configurable)
• Voltage Range: 3.3V to 5V (logic and power)
• Current Consumption: ~5mA (typical)
• Operating Temperature: -40°C to +85°C
• Dimensions: 25mm x 17mm x 4mm
• Weight: 2g

The Adafruit LSM6DS3TR-C + LIS3MDL module features the following pins:

1. Power the Module: Connect the VIN pin to a 3.3V or 5V power source and the GND pin to ground.
2. Connect I²C Lines:
   • Connect the SCL pin to the I²C clock line of your microcontroller.
   • Connect the SDA pin to the I²C data line of your microcontroller.
3. Optional Connections:
   • Use the INT1, INT2, or DRDY pins for interrupt-driven applications.
   • If using SPI, connect the CS pin and configure the microcontroller accordingly.
4. Install Required Libraries: Use the Adafruit Unified Sensor library and the Adafruit LSM6DS3TR-C and LIS3MDL libraries for Arduino.

Below is an example Arduino sketch to read accelerometer, gyroscope, and magnetometer data using I²C:

#include <Wire.h>
#include <Adafruit_Sensor.h>
#include <Adafruit_LSM6DS33.h>
#include <Adafruit_LIS3MDL.h>

// Create sensor objects
Adafruit_LSM6DS33 lsm6ds33;
Adafruit_LIS3MDL lis3mdl;

void setup() {
  Serial.begin(115200);
  while (!Serial) delay(10); // Wait for Serial Monitor to open

  // Initialize LSM6DS33
  if (!lsm6ds33.begin_I2C()) {
    Serial.println("Failed to find LSM6DS33 chip");
    while (1) delay(10);
  }
  Serial.println("LSM6DS33 Found!");

  // Initialize LIS3MDL
  if (!lis3mdl.begin_I2C()) {
    Serial.println("Failed to find LIS3MDL chip");
    while (1) delay(10);
  }
  Serial.println("LIS3MDL Found!");
}

void loop() {
  // Read accelerometer data
  sensors_event_t accel, gyro, temp;
  lsm6ds33.getEvent(&accel, &gyro, &temp);

  // Read magnetometer data
  sensors_event_t mag;
  lis3mdl.getEvent(&mag);

  // Print accelerometer data
  Serial.print("Accel X: "); Serial.print(accel.acceleration.x); Serial.print(" m/s^2 ");
  Serial.print("Y: "); Serial.print(accel.acceleration.y); Serial.print(" m/s^2 ");
  Serial.print("Z: "); Serial.print(accel.acceleration.z); Serial.println(" m/s^2");

  // Print gyroscope data
  Serial.print("Gyro X: "); Serial.print(gyro.gyro.x); Serial.print(" rad/s ");
  Serial.print("Y: "); Serial.print(gyro.gyro.y); Serial.print(" rad/s ");
  Serial.print("Z: "); Serial.print(gyro.gyro.z); Serial.println(" rad/s");

  // Print magnetometer data
  Serial.print("Mag X: "); Serial.print(mag.magnetic.x); Serial.print(" uT ");
  Serial.print("Y: "); Serial.print(mag.magnetic.y); Serial.print(" uT ");
  Serial.print("Z: "); Serial.print(mag.magnetic.z); Serial.println(" uT");

  delay(500); // Delay for readability
}

• I²C Pull-Up Resistors: Ensure your I²C bus has appropriate pull-up resistors (typically 4.7kΩ).
• Power Supply: Use a stable power source to avoid noise in sensor readings.
• Orientation: Mount the IMU securely and in the correct orientation for accurate measurements.
• Calibration: Perform sensor calibration for precise results, especially for the magnetometer.

1. Sensor Not Detected:

   • Ensure the I²C connections (SCL, SDA) are correct.
   • Verify the I²C address matches the default or configured value.
   • Check for loose or faulty wiring.

2. Incorrect or No Data:

   • Confirm the power supply voltage is within the specified range.
   • Ensure the sensor is not exposed to excessive vibrations or magnetic interference.

3. I²C Communication Errors:

   • Check for conflicting I²C addresses on the bus.
   • Verify pull-up resistors are present on the I²C lines.

• Use a logic analyzer or oscilloscope to debug I²C communication issues.
• Test the module with a known working microcontroller and example code.
• Update the Adafruit libraries to the latest version for compatibility.

By following this documentation, you can effectively integrate the Adafruit LSM6DS3TR-C + LIS3MDL IMU into your projects for precise motion and orientation sensing.