3 axes magnetic field sensor HMC5883 GY-271

Overview

The sensor is small and can communicate on the I2C bus, so you only need two connections to communicate with a microcontroller.
The module decomposes the infusion on the two axes and so you can use it as a compass.

Specifications

Voltage: 3V - 5V (limit switch included);
Current: 740uA;
Measures between -8 and +8 Gauss;
Includes 12-bit ADC;

Output rate: maximum 116Hz;
I2C communication at maximum 400kHz;
Dimensions: 19 x 14 x 2mm.

PIN Config:

1. VCC: 3V-5V DC

2. GND: ground

3. SCL: analog input (A5)

4. SDA: analog input (A4)

5. DRDY: not connected

Datasheet & Tutorial

http://www.robotpark.com/image/data/PRO/91457/GY_271_ELECTRONIC_COMPASS.pdf