Triple-axis Magnetometer (Compass) Board - HMC5883L.
He told you "Go West, young maker!" - but you don't know which way is West! Ah, if only you had this triple-axis magnetometer compass module. A magnetometer can sense where the strongest magnetic force is coming from, generally used to detect magnetic north.
Adafruit based this breakout 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, Adafruit 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. Data can then be read 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 Adafruit have a nice little Arduino library with a matching tutorial to get you started. Simply download the 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 the 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!
- I2C interface
- 1-2 degree heading accuracy
- Integrated 12-bit ADC
- 160Hz max data rate
- Range of -8 to +8 Gauss