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 attached, like the lid of a box, or maybe a statue that unlocks your secret lair when placed on your mantle.

The TLD493D excels at measuring nearby magnetic fields in three dimensions. It’s not going to 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

Features:

1. Digital output via 2-wire based standard I2C interface up to 1 MBit/sec
2. 12-bit data resolution for each measurement direction
3. Bx, By, and Bz linear field measurement up to +130mT
4. Excellent matching of X/Y measurement for accurate angle sensing
5. TLV493D – 3-Axis Magnetometer
6. Communication Interface: I2C
7. Supply Voltage – 3.3V or 5V logic levels