'\" Copyright (c) 2003-2004 Paul H Alfille, MD
'\" Program manual page for the OWFS -- 1-wire filesystem package
'\" Based on Dallas Semiconductor, Inc's datasheets, and trial and error.
'\" Free for all use. No warranty. None. Use at your own risk.
is a wiring protocol and series of devices designed and manufactured
by Dallas Semiconductor, Inc. The bus is a low-power low-speed low-connector
scheme where the data line can also provide power.
Each device is uniquely and unalterably numbered during manufacture. There are a wide variety
of devices, including memory, sensors (humidity, temperature, voltage,
contact, current), switches, timers and data loggers. More complex devices (like
thermocouple sensors) can be built with these basic devices. There are also
1-wire devices that have encryption included.
The 1-wire scheme uses a single
.I bus master
on the same wire. The bus master initiates all communication. The slaves can be
individually discovered and addressed using their unique ID.
Bus masters come in a variety of configurations including serial, parallel, i2c, network or USB
.SS OWFS design
is a suite of programs that designed to make the 1-wire bus and its
devices easily accessible. The underlying principle is to create a virtual
filesystem, with the unique ID being the directory, and the individual
properties of the device are represented as simple files that can be read and written.
Details of the individual slave or master design are hidden behind a consistent interface. The goal is to
provide an easy set of tools for a software designer to create monitoring or control applications. There
are some performance enhancements in the implementation, including data caching, parallel access to bus
masters, and aggregation of device communication. Still the fundamental goal has been ease of use, flexibility
and correctness rather than speed.