What is 1-wire?

1-wire is a technology defined by Dallas/Maxim and used in their range of iButtons and other 1-wire sensors which can measure and control a wide range of environmental parameters. Communication with the devices is via a two wire bus consisting of data and ground. Each device has a unique, factory programmed address which cannot be altered and which is guaranteed unique. This fact alone makes them useful for key access and identification systems, but they have many other useful functions ranging from non-volatile storage, to temperature and humidity sensing, switching and voltage measurement.