NAME

owdir, owread, owwrite, owget, owexist, owpresent - lightweight owserver access

SYNOPSIS

Minimal options

owdir -s [host:]port [directory]
owread -s [host:]port filepath
owwrite -s [host:]port filepath value
owget -s [host:]port [directory] | filepath

Server discovery

owdir --autoserver [directory]
owread --autoserver filepath
owwrite --autoserver filepath value
owget --autoserver [directory] | filepath

Full options

owdir -q --quiet -f --format f[.]i[[.]c] ] [ --dir ] -s [host:]port [directory] [directory2 ...]

owread -q --quiet -C --celsius -K --kelvin -F --fahrenheit -R --rankine [ --hex ] [ --start= offset ] [ --size= bytes ] -s [host:]port filepath [filepath2 ...]

owwrite -q --quiet -C --celsius -K --kelvin -F --fahrenheit -R --rankine [ --hex ] [ --start= offset ] -s [host:]port filepath value [filepath2 value2 ...]

owget -q --quiet -f --format f[.]i[[.]c] -C --celsius -K --kelvin -F --fahrenheit -R --rankine [ --hex ] [ --start= offset ] [ --size= bytes ] [ --dir ] -s [host:]port [directory] | filepath

Version

owdir -V --version
owread -V --version
owwrite -V --version
owget -V --version

Help

owdir -h | --help
owread -h | --help
owwrite -h | --help
owget -h | --help

DESCRIPTION

1-Wire

1-wire 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 bus master and multiple slaves 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 adapters.

OWFS design

OWFS 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.

OWSHELL programs

owdir owread owwrite and owget are collectively called the owshell programs. They allow lightweight access to an owserver (1) for use in command line scripts.

Unlike owserver (1) owhttpd (1) owftpd (1) owhttpd (1) there is not persistent connection with the 1-wire bus, no caching and no multithreading. Instead, each program connects to a running owserver (1) and performs a quick set of queries.

owserver (1) performs the actual 1-wire connection (to physical 1-wire buses or other owserver programs), performs concurrency locking, caching, and error collection.

owshell programs are intended for use in command line scripts. An alternative approach is to mount an owfs (1) filesystem and perform direct file lists, reads and writes.

owdir

owdir performs a directory listing. With no argument, all the devices on the main 1-wire bus will be listed. Given the name of a 1-wire device, the available properties will be listed. It is the equivalent of

: ls directory

in the owfs (1) filesystem.

owread

owread obtains for value of a 1-wire device property. e.g. 28.0080BE21AA00/temperature gives the DS18B20 temperature. It is the equivalent of

: cat filepath

in the owfs (1) filesystem.

owwrite

owwrite performs a change of a property, changing a 1-wire device setting or writing to memory. It is the equivalent of

: echo value > filepath

in the owfs (1) filesystem.

owget

owget (1) is a convenience program, combining the function of owdir (1) and owread (1) by first trying to read the argument as a directory, and if that fails as a 1-wire property.

STANDARD OPTIONS

--autoserver

Find an owserver using the Service Discovery protocol. Essentially Apple's Bonjour (aka zeroconf). Only the first owserver will be used, and that choice is probably arbitrary.

-s [host:]port

Connect via tcp (network) to an owserver process that is connected to a physical 1-wire bus. This allows multiple processes to share the same bus. The owserver process can be local or remote.

If the server option is not specified, the default is the local machine and the IANA allocated default port of 4304. Thus "-s localhost:4304" is the equivalent.

DATA OPTIONS

--hex

Hexadecimal mode. For reading data, each byte of character will be displayed as two characrters 0-9ABCDEF. Most useful for reading memory locations. No spaces between data.

Writing data in hexadecimal mode just means that the data should be given as one long hexadecimal string.

--start=offset

Read or write memory locations starting at the offset byte rather than the beginning. An offset of 0 means the beginning (and is the default).

--size=bytes

Read up to the specified number of bytes of a memory location.

HELP OPTIONS

-h --help

Shows (this) basic summary of options.

-V --version

Version of this program.

DISPLAY OPTIONS

--dir

Modify the display of directories to indicate which entries are also directories. A directory member will have a trailing '/' if it is a directory itself. This aids recursive searches.

-f --format f[.]i[[.]c]

Display format for the 1-wire devices. Each device has a 8 byte address, consisting of:

f: family code, 1 byte
i: ID number, 6 bytes
c: CRC checksum, 1 byte

Possible formats are f.i (default, 01.A1B2C3D4E5F6), fi fic f.ic f.i.c and fi.c

All formats are accepted as input, but the output will be in the specified format.

EXAMPLE

owdir -s 3000 --format fic: Get the device listing (full 16 hex digits, no dots) from the local owserver at port 3000
owread -F --autoserver 51.125499A32000/typeK/temperature: Read temperature from the DS2751-based thermocouple on an auto-discovered owserver Temperature in fahrenheit.
owwrite -s 10.0.1.2:3001 32.000800AD23110/pages/page.1 "Passed": Connect to a OWFS server process ( owserver ) that was started on another machine at tcp port 3001 and write to the memory of a DS2780

AVAILABILITY

http://www.owfs.org

AUTHOR

Paul Alfille (paul.alfille@gmail.com)