micro:bit and HMC5883L magnetometer example

The Honeywell HMC5883L is a surface-mount, multi-chip module designed for low-field magnetic sensing with a digital interface for applications such as lowcost compassing and magnetometry. The HMC5883L includes our state-of-theart, high-resolution HMC118X series magneto-resistive sensors plus an ASIC containing amplification, automatic degaussing strap drivers, offset cancellation, and a 12-bit ADC that enables 1° to 2° compass heading accuracy. The I2C serial bus allows for easy interface. The HMC5883L is a 3.0×3.0x0.9mm surface mount 16-pin leadless chip carrier (LCC).

Applications for the HMC5883L include Mobile Phones, Netbooks, Consumer Electronics, Auto Navigation Systems, and Personal Navigation Devices.

The HMC5883L utilizes Honeywell’s Anisotropic Magnetoresistive (AMR) technology that provides advantages over other magnetic sensor technologies. These anisotropic, directional sensors feature precision in-axis sensitivity and linearity. These sensors’ solid-state construction with very low cross-axis sensitivity is designed to measure both the direction and the magnitude of Earth’s magnetic fields, from milli-gauss to 8 gauss. Honeywell’s Magnetic Sensors are among the most sensitive and reliable low-field sensors in the industry

HMC5883L

Connection

Code

[codesyntax lang=”cpp”]

#include <Wire.h> //I2C Arduino Library

#define addr 0x1E //I2C Address for The HMC5883

void setup(){
  
  Serial.begin(9600);
  Wire.begin();
  
  
  Wire.beginTransmission(addr); //start talking
  Wire.write(0x02); // Set the Register
  Wire.write((byte)0x00); // Tell the HMC5883 to Continuously Measure
  Wire.endTransmission();
}


void loop(){
  
  int x,y,z; //triple axis data

  //Tell the HMC what regist to begin writing data into
  Wire.beginTransmission(addr);
  Wire.write(0x03); //start with register 3.
  Wire.endTransmission();
  
 
 //Read the data.. 2 bytes for each axis.. 6 total bytes
  Wire.requestFrom(addr, 6);
  if(6<=Wire.available()){
    x = Wire.read()<<8; //MSB  x 
    x |= Wire.read(); //LSB  x
    z = Wire.read()<<8; //MSB  z
    z |= Wire.read(); //LSB z
    y = Wire.read()<<8; //MSB y
    y |= Wire.read(); //LSB y
  }
  
  // Show Values
  Serial.print("X Value: ");
  Serial.println(x);
  Serial.print("Y Value: ");
  Serial.println(y);
  Serial.print("Z Value: ");
  Serial.println(z);
  Serial.println();
  
  delay(500);
}

[/codesyntax]

Links
1pcs/lot GY-271 , HMC5883 HMC5883L module electronic compass compass module three-axis magnetic field sensor