How to Use Sparkfun 9DOF Breakout Board: Examples, Pinouts, and Specs

The Sparkfun 9DOF Breakout Board (SKU: SEN-13284) is a compact and versatile sensor module that integrates three essential motion-sensing components: a 3-axis accelerometer, a 3-axis gyroscope, and a 3-axis magnetometer. This combination provides a total of nine degrees of freedom (9DOF), enabling precise motion tracking, orientation sensing, and environmental awareness.

This breakout board is ideal for applications such as:

• Robotics and drone navigation
• Wearable devices and fitness trackers
• Virtual reality (VR) and augmented reality (AR) systems
• Motion capture and gesture recognition
• Scientific experiments and data logging

The Sparkfun 9DOF Breakout Board is built around the LSM9DS1 sensor, which combines the accelerometer, gyroscope, and magnetometer into a single package. Below are the key technical details:

The breakout board has the following pin layout:

1. Power Supply: Connect the VIN pin to a 3.3V power source and the GND pin to ground.
2. I2C Communication:
   • Connect the SDA pin to the SDA pin on your microcontroller.
   • Connect the SCL pin to the SCL pin on your microcontroller.
3. SPI Communication (optional):
   • Use the CS_AG, CS_M, SDO_AG, and SDO_M pins for SPI communication.
4. Interrupts (optional): Use the INT1 and INT2 pins for interrupt-driven applications.

Below is an example of how to use the Sparkfun 9DOF Breakout Board with an Arduino UNO via I2C.

#include <Wire.h>
#include <SparkFunLSM9DS1.h> // Include the SparkFun LSM9DS1 library

// Create an instance of the LSM9DS1 object
LSM9DS1 imu;

// Define I2C address for the LSM9DS1
#define LSM9DS1_M  0x1E // Magnetometer I2C address
#define LSM9DS1_AG 0x6B // Accelerometer and gyroscope I2C address

void setup() {
  Serial.begin(9600); // Initialize serial communication
  Wire.begin();       // Initialize I2C communication

  // Initialize the LSM9DS1 sensor
  if (!imu.begin(LSM9DS1_AG, LSM9DS1_M)) {
    Serial.println("Failed to initialize LSM9DS1. Check connections.");
    while (1); // Halt the program if initialization fails
  }

  Serial.println("LSM9DS1 initialized successfully!");
}

void loop() {
  // Read accelerometer data
  if (imu.accelAvailable()) {
    imu.readAccel();
    Serial.print("Accel X: "); Serial.print(imu.ax);
    Serial.print(" Y: "); Serial.print(imu.ay);
    Serial.print(" Z: "); Serial.println(imu.az);
  }

  // Read gyroscope data
  if (imu.gyroAvailable()) {
    imu.readGyro();
    Serial.print("Gyro X: "); Serial.print(imu.gx);
    Serial.print(" Y: "); Serial.print(imu.gy);
    Serial.print(" Z: "); Serial.println(imu.gz);
  }

  // Read magnetometer data
  if (imu.magAvailable()) {
    imu.readMag();
    Serial.print("Mag X: "); Serial.print(imu.mx);
    Serial.print(" Y: "); Serial.print(imu.my);
    Serial.print(" Z: "); Serial.println(imu.mz);
  }

  delay(500); // Delay for readability
}

• Use a level shifter if interfacing with a 5V microcontroller, as the breakout board operates at 3.3V logic.
• Keep I2C lines as short as possible to avoid signal degradation.
• Use decoupling capacitors near the power supply pins to reduce noise.

1. Sensor Not Responding:

   • Ensure the VIN pin is connected to a 3.3V power source.
   • Verify the I2C connections (SDA and SCL) and ensure pull-up resistors are present if needed.
   • Check the I2C addresses in your code (0x1E for magnetometer, 0x6B for accelerometer/gyroscope).

2. Incorrect or No Data:

   • Confirm that the sensor is properly initialized in the code.
   • Ensure the correct range settings are configured for each sensor.

3. Noise in Sensor Readings:

   • Use proper grounding and shielding to minimize electrical noise.
   • Apply software filtering or averaging to smooth out the data.

Q: Can I use this board with a 5V microcontroller?
A: Yes, but you must use a logic level shifter to convert the 5V signals to 3.3V.

Q: How do I switch between I2C and SPI modes?
A: By default, the board operates in I2C mode. To use SPI, connect the CS_AG and CS_M pins to your microcontroller and configure the SPI settings in your code.

Q: What is the maximum sampling rate of the sensors?
A: The accelerometer and gyroscope can sample at up to 952 Hz, while the magnetometer can sample at up to 80 Hz.