Does a non-I2C compass exist?

Other Hardware Sensors
2

Technically, anything is possible *

http://www.digikey.com/product-search/en/sensors-transducers/magnetic-sensors-compass-magnetic-field-modules/1967220

http://www.mouser.com/Sensors/Motion-Position-Sensors/_/N-6g7q6?Keyword=compass+module&FS=True

Scroll to the right for interface types.

  • Quote from Mitsubishu car ad.