table of contents
- NAME
- SYNOPSIS
- DESCRIPTION
- Device Options (1-wire Bus Master)
- * Serial devices
- * USB devices
- * I2C devices
- * Network devices
- * Simulated devices
- * w1 kernel module
- SPECIFIC OPTIONS
- TEMPERATURE SCALE OPTIONS
- PRESSURE SCALE OPTIONS
- FORMAT OPTIONS
- JOB CONTROL OPTIONS
- CONFIGURATION FILE
- HELP OPTIONS
- TIME OPTIONS
- EXAMPLE
- SEE ALSO
- AVAILABILITY
- AUTHOR
other versions
- jessie 2.9p8-6
- stretch 3.1p5-1
- testing 3.2p2-2+b3
- stretch-backports 3.2p2-2~bpo9+1
- unstable 3.2p3+dfsg1-2+b1
other sections
OWFS(1) | One-Wire File System | OWFS(1) |
NAME¶
owfs - 1-wire filesystemSYNOPSIS¶
owfs [ -c config ] -d serialport | -u | -s [host:]port -m mountdirDESCRIPTION¶
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 priciple 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 fundemental goal has been ease of use, flexibility and correctness rather than speed.owfs¶
owfs (1) is the filesystem client of the OWFS family of programs. It runs on linux, freebsd and Mac OS X, and requires the fuse kernel module and library. (http://fuse.sourceforge.net) which is a user-mode filesystem driver. Essentially, the entire 1-wire bus is mounted to a place in your filesystem. All the 1-wire devices are accessible using standard file operations (read, write, directory listing). The system is safe, no actual files are exposed, these files are virtual. Not all operations are supported. Specifically, file creation, deletion, linking and renaming are not allowed. (You can link from outside to a owfs file, but not the other way around).Device Options (1-wire Bus Master)¶
These options specify the device (bus master) connecting the computer to the 1-wire bus. The 1-wire slaves are connected to the 1-wire bus, and the bus master connects to a port on the computer and controls the 1-wire bus. The bus master is either an actual physical device, the kernel w1 module, or an owserver (1). At least one device option is required. There is no default. More than one device can be listed, and all will be used. (A logical union unless you explore the /bus.n/ directories.) Linux and BSD enforce a security policy restricting access to hardware ports. You must have sufficient rights to access the given port or access will silently fail.* Serial devices¶
port specifies a serial port, e.g. /dev/ttyS0- -d port | --device=port (DS2480B)
- DS2480B-based bus master (like the DS9097U or the LINK in emulation mode). If the adapter doesn't respond, a passive type (DS9907E or diode/resistor) circuit will be assumed.
- --serial_flextime | --serial_regulartime (DS2480B)
-
- --baud=1200|9600|19200|38400|57600|115200 (DS2480B,LINK,HA5)
- Sets the initial serial port communication speed for all bus masters. Not
all serial devices support all speeds. You can change the individual bus
master speed for the LINK and DS2880B in the
interface/settings directory. The HA5 speed is set in hardware, so
the command line buad rate should match that rate.
- --straight_polarity | --reverse_polarity (DS2480B)
- Reverse polarity of the DS2480B output transistors? Not needed for the DS9097U, but required for some other designs.
- --link=port (LINK)
- iButtonLink LINK adapter (all versions) in non-emulation mode. Uses an ascii protocol over serial.
- --ha7e=port (HA7E)
- Embedded Data Systems HA7E adapter ( and HA7S ) in native ascii mode.
- --ha5=port | --ha5=port:a | --ha5=port:acg (HA5)
- Embedded Data Systems HA5 mutidrop adapter in native ascii mode. Up to 26 adapters can share the same port, each with an assigned letter. If no letter specified, the program will scan for the first response (which may be slow).
- --checksum | --no_checksum (HA5)
-
- --passive=port | --ha2=port | --ha3=port | --ha4b=port (Passive)
- Passive 1-wire adapters. Powered off the serial port and using passive electrical components (resitors and diodes).
- --8bit | --6bit (Passive)
-
- --timeout_serial=5
- Timeout (in seconds) for all serial communications. 5 second default. Can be altered dynamically under /settings/timeout/serial
* USB devices¶
The only supported true USB bus masters are based on the DS2490 chip. The most common is the DS9490R which has an included 1-wire ID slave with family code 81. There are also bus masters based on the serial chip with a USB to serial conversion built in. These are supported by the serial bus master protocol.- -u | --usb
- DS2490 based bus master (like the DS9490R).
- -u2 | --usb=2
- Use the second USB bus master. (The order isn't predicatble, however, since the operating system does not conssitently order USB devices).
- -uall | --usb=ALL
- Use all the USB devices.
- --usb_flextime | --usb_regulartime
- Changes the details of 1-wire waveform timing for certain network configurations.
- --altusb
- Willy Robion's alternative USB timing.
- --timeout_usb=5
- Timeout for USB communications. This has a 5 second default and can be changed dynamically under /settings/timeout/usb
* I2C devices¶
I2C is 2 wire protocol used for chip-to-chip communication. The bus masters: DS2482-100, DS2482-101 and DS2482-800 can specify (via pin voltages) a subset of addresses on the i2c bus. Those choices are i2c_address- 0,1,2,3
- 0x18,0x19,0x1A,0x1B
- 4,5,6,7
- 0x1C,0x1D,0x1E,0x1F (DS2482-800 only)
- -d port | --device=port
- This simple form only permits a specific port and the first available i2c_address
- --i2c=port | --i2c=port:i2c_address | --i2c=port:ALL
- Specific i2c port and the i2c_address is either the first, specific, or all or them. The i2c_address is 0,1,2,...
- --i2c | --i2c=: | --i2c=ALL:ALL
- Search the available i2c buses for either the first, the first, or every i2c adapter.
* Network devices¶
These bus masters communicate via the tcp/ip network protocol and so can be located anywhere on the network. The network_address is of the form tcp_address:port E.g. 192.168.0.1:3000 or localhost:3000- --link=network_address
- LinkHubE network LINK adapter by iButtonLink
- --ha7net=network_address | --ha7net
- HA7Net network 1-wire adapter with specified tcp address or discovered by
udp multicast. By Embedded Data Systems
- --etherweather=network_address
- Etherweather adapter
- -s network_address | --server=network_address
- Location of an owserver (1) program that talks to the 1-wire bus. The default port is 4304.
- --timeout_network=5
- Timeout for network bus master communications. This has a 1 second default and can be changed dynamically under /settings/timeout/network
* Simulated devices¶
Used for testing and development. No actual hardware is needed. Useful for separating the hardware development from the rest of the software design.- devices
- is a list of comma-separated 1-wire devices in the following formats. Note that a valid CRC8 code is created automatically.
- 10,05,21
- Hexidecimal family codes (the DS18S20, DS2405 and DS1921 in this example).
- 10.12AB23431211
- A more complete hexidecimal unique address. Useful when an actual hardware device should be simulated.
- DS2408,DS2489
- The 1-wire device name. (Full ID cannot be speciifed in this format).
- --fake=devices
- Random address and random values for each read. The device ID is also random (unless specified).
- --temperature_low=12 --temperature_high=44
- Specify the temperature limits for the fake adapter simulation. These should be in the same temperature scale that is specified in the command line. It is possible to change the limits dynamically for each adapter under /bus.x/interface/settings/simulated/[temperature_low|temperature_high]
- --tester=devices
- Predictable address and predictable values for each read. (See the website for the algorhythm).
* w1 kernel module¶
This a linux-specific option for using the operating system's access to bus masters. Root access is required and the implementation was still in progress as of owfs v2.7p12 and linux 2.6.30. Bus masters are recognized and added dynamically. Details of the physical bus master are not accessible, bu they include USB, i2c and a number of GPIO designs on embedded boards. Access is restrict to superuser due to the netlink broadcast protocol employed by w1. Multitasking must be configured (threads) on the compilation.- --w1
- Use the linux kernel w1 virtual bus master.
- --timeout_w1=10
- Timeout for w1 netlink communications. This has a 10 second default and can be changed dynamically under /settings/timeout/w1
SPECIFIC OPTIONS¶
-m --mountpoint=directory_path¶
Path of a directory to mount the 1-wire file system The mountpoint is required. There is no default.--allow_other¶
Shorthand for fuse mount option "-o allow_other" Allows uther users to see the fuse (owfs) mount point and file system. Requires a setting in /etc/fuse.conf as well.--fuse-opt options¶
Sends options to the fuse-mount process. Options should be quoted, e.g. "TEMPERATURE SCALE OPTIONS¶
-C --Celsius¶
-F --Fahrenheit¶
-K --Kelvin¶
-R --Rankine¶
Temperature scale used for data output. Celsius is the default. Can also be changed within the program at /settings/units/temperature_scalePRESSURE SCALE OPTIONS¶
--mbar (default)¶
--atm¶
--mmHg¶
--inHg¶
--psi¶
--Pa¶
Pressure scale used for data output. Millibar is the default. Can also be changed within the program at /settings/units/pressure_scaleFORMAT OPTIONS¶
Choose the representation of the 1-wire unique identifiers. OWFS uses these identifiers as unique directory names. Although several display formats are selectable, all must be in family-id-crc8 form, unlike some other programs and the labelling on iButtons, which are crc8-id-family form.-f --format="f[.]i[[.]c]"¶
Display format for the 1-wire devices. Each device has a 8byte address, consisting of:- f
- family code, 1 byte
- i
- ID number, 6 bytes
- c
- CRC checksum, 1 byte
JOB CONTROL OPTIONS¶
-r --readonly¶
-w --write¶
Do we allow writing to the 1-wire bus (writing memory, setting switches, limits, PIOs)? The write option is available for symmetry, it's the default.-P --pid-file filename¶
Places the PID -- process ID of owfs into the specified filename. Useful for startup scripts control.--background | --foreground¶
Whether the program releases the console and runs in the background after evaluating command line options. background is the default.--error_print=0|1|2|3¶
- =0
- default mixed destination: stderr foreground / syslog background
- =1
- syslog only
- =2
- stderr only
- =3
- /dev/null (quiet mode).
--error_level=0..9¶
- =0
- default errors only
- =1
- connections/disconnections
- =2
- all high level calls
- =3
- data summary for each call
- =4
- details level
- >4
- debugging chaff
CONFIGURATION FILE¶
-c file | --configuration file¶
Name of an owfs (5) configuration file with more command line parameters +.PP +On Debian, +.B owfs (1) +always reads +.I /etc/owfs.confHELP OPTIONS¶
See also this man page and the web site http://www.owfs.org-h --help=[device|cache|program|job|temperature]¶
Shows basic summary of options.- device
- 1-wire bus master options
- cache
- cache and communication size and timing
- program
- mountpoint or TCP server settings
- job
- control and debugging options
- temperature
- Unique ID display format and temperature scale
-V --version¶
Version of this program and related libraries.TIME OPTIONS¶
Timeouts for the bus masters were previously listed in Device options. Timeouts for the cache affect the time that data stays in memory. Default values are shown.--timeout_volatile=15¶
Seconds until a volatile property expires in the cache. Volatile properties are those (like temperature) that change on their own. Can be changed dynamically at /settings/timeout/volatile--timeout_stable=300¶
Seconds until a stable property expires in the cache. Stable properties are those that shouldn't change unless explicitly changed. Memory contents for example. Can be changed dynamically at /settings/timeout/stable--timeout_directory=60¶
Seconds until a directory listing expires in the cache. Directory lists are the 1-wire devices found on the bus. Can be changed dynamically at /settings/timeout/directory--timeout_presence=120¶
Seconds until the presence and bus location of a 1-wire device expires in the cache. Can be changed dynamically at /settings/timeout/presence There are also timeouts for specific program responses:--timeout_server=5¶
Seconds until the expected response from the owserver (1) is deemed tardy. Can be changed dynamically at /settings/timeout/server--timeout_ftp=900¶
Seconds that an ftp session is kept alive. Can be changed dynamically at /settings/timeout/ftpEXAMPLE¶
- owfs -d /dev/ttyS0 -m /mnt/1wire
- Bus master on serial port
- owfs -F -u -m /mnt/1wire
- USB adapter, temperatures reported in Fahrenheit
- owfs -s 10.0.1.2:4304 -m /mnt/1wire
- Connect to an owserver (1) process that was started on another machine at tcp port 4304
SEE ALSO¶
Programs¶
owfs (1) owhttpd (1) owftpd (1) owserver (1) owdir (1) owread (1) owwrite (1) owpresent (1) owtap (1)Configuration and testing¶
owfs (5) owtap (1) owmon (1)Language bindings¶
owtcl (3) owperl (3) owcapi (3)Clocks¶
DS1427 (3) DS1904(3) DS1994 (3) DS2404 (3) DS2404S (3) DS2415 (3) DS2417 (3)ID¶
DS2401 (3) DS2411 (3) DS1990A (3)Memory¶
DS1982 (3) DS1985 (3) DS1986 (3) DS1991 (3) DS1992 (3) DS1993 (3) DS1995 (3) DS1996 (3) DS2430A (3) DS2431 (3) DS2433 (3) DS2502 (3) DS2506 (3) DS28E04 (3) DS28EC20 (3)Switches¶
DS2405 (3) DS2406 (3) DS2408 (3) DS2409 (3) DS2413 (3) DS28EA00 (3)Temperature¶
DS1822 (3) DS1825 (3) DS1820 (3) DS18B20 (3) DS18S20 (3) DS1920 (3) DS1921 (3) DS1821 (3) DS28EA00 (3) DS28E04 (3)Humidity¶
DS1922 (3)Voltage¶
DS2450 (3)Resistance¶
DS2890 (3)Multifunction (current, voltage, temperature)¶
DS2436 (3) DS2437 (3) DS2438 (3) DS2751 (3) DS2755 (3) DS2756 (3) DS2760 (3) DS2770 (3) DS2780 (3) DS2781 (3) DS2788 (3) DS2784 (3)Counter¶
DS2423 (3)LCD Screen¶
LCD (3) DS2408 (3)Crypto¶
DS1977 (3)Pressure¶
DS2406 (3) -- TAI8570AVAILABILITY¶
http://www.owfs.orgAUTHOR¶
Paul Alfille (paul.alfille@gmail.com)2004 | OWFS Manpage |