Compass Sensor QMC5883L / HMC5883L GY273

HW-127 HMC5883L or QMC5883L 3-axis Electronic Compass Module Magnetic Field Sensor(with Original QMC5883L or HMC5883L Driver Chip) is designed for low field magnetic sensing with a digital interface and it is perfect to give precise heading information.
This compact sensor fits into small projects such as UAVs and robot navigation systems. The sensor converts any magnetic field to a differential voltage output on 3 axes. This voltage shift is the raw digital output value, which can then be used to calculate headings or sense magnetic fields coming from different directions.

A development board that provides a simple interface for the QMC5883L/ HMC5883L (three-axis magnetic field module).

This module is based on a popular and well-loved magnetometer, the HMC5883L. This compact sensor uses I2C to communicate and its very easy to use. Since it’s a 3.3V max chip, we added circuitry to make it 5V-safe logic and power, for easy use with either 3 or 5V microcontrollers. Simply connect VCC to +3-5V and ground to ground. Then read data from the I2C clock and data pins. There’s also a Data Ready pin you can use to speed up reads (check the datasheet for details)

If using with an Arduino, its extra-easy to get started as electropeak already wrote a nice little Arduino interfacing tutorial to get you started. Simply download our library and connect the SCL pin to your Arduino’s I2C clock pin, and SDA pin to your Arduino’s I2C data pin and upload our test example sketch to read out magnetic field data and heading (i.e. which way is north)

This is the same magnetometer sensor that is inside the LSM303. So if you want an accelerometer as well as a magnetometer, check out the LSM303 – it has basically this sensor + a nice digital 3-axis accelerometer!