The TLV493D 3-axis magnetometer is a great little sensor for detecting magnets in 3D. In fact, the manufacturer Infineon suggests it could be used to make a joystick! You could also use it for other cool things like detecting objects with magnets on them, like the lid of a box, or a statue that unlocks your secret lair when placed on the mantle? The TLD493D excels at measuring nearby magnetic fields in three dimensions. It won't make a good compass, it's not sensitive enough to pick up the Earth's magnetic field, but you can use it to track the movement of nearby magnets in three dimensions. Here are some specs: Digital output via a standard 2-wire based I2C interface at up to 1 MBit/sec 12-bit data resolution for each measured direction Linear field measurements up to +130 mT for Bx, By, and Bz Excellent matching of X/Y measurements for accurate angle sensing As we are wont to do, we placed the TLV on a breakout PCB along with the circuitry that supports it, making the TLV easy to use. The combination of a voltage regulator and logic level translation allows it to be used with a range of microcontrollers with 3.3V or 5V logic levels. We even provide a pin for you to use excess 3.3V power that the TLV493D does not require. Colour:Black Material:ABS Package Contents: 3x TLV493D 3D Magnetometer 3x Pin Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.