LCD(3) - Linux man page online | Library functions

LCD controller.

LCD(3) One-Wire File System LCD(3)


LCD - LCD controller


1-wire LCD controller by Louis Swart FF [.]XXXXXXXXXXXX[XX][/[ backlight | counters.[0-3|ALL] | cumulative.[0-3|ALL] | branch.[0-1|ALL] | data | gpio.[0-3|ALL] | LCDon | line16.[0-3|ALL] | line20.[0-3|ALL] | line40.[0|1|ALL] | memory | register | screen16 | screen20 | screen40 | version | address | crc8 | id | locator | r_address | r_id | r_locator | type ]]




backlight write-only,yes-no Write a non-zero value to turn on the LCD backlight. Write zero to turn off. counters[0-3,ALL] read-only,unsigned integer Read the number of times the gpio has been externally changed. If wired to a push switch, will count twice per button press. The LCD firmware resets all the counter when any one is read. Use the ALL extension to read them all, simultaneously, or use the cumulative prop‐ erty instead. ALL is an aggregate of the properties, comma separated. Read atomically. cumulative[0-3,ALL] read-write,unsigned integer Cumulative sum of the counters property. To reset, write a zero. The cumulative counter can have any value written, which allows preservation of counts across program restarts if the value at program termination is stored. Reading cumulative will reset the counters property. All the cumulative counters will be updated so that no counts will be lost. Reads of counters can be interspersed without los‐ ing cumulative accuracy. Note: cumulative requires the caching system be compiled into libow. ALL is an aggregate of the properties, comma separated. data read-write,unsigned int Contents of the LCD data byte (see datasheet). Not usually needed. LCDon write-only,yes-no Write a non-zero value to turn on the LCD screen (also clears). Write a zero to turn off. line16[0-3,ALL] line20[0-3,ALL] line40[0-1,ALL] write-only,ascii Write text to the LCD screen. Assumes 16/20/40 char width. (Cannot be determined from con‐ troller). ALL is an aggregate of the properties, comma separated. Each is set in turn. memory read-write,binary 112 bytes of on-board memory. register read-write,unsigned int Contents of the LCD register (see datasheet). Not usually needed. screen16 screen20 screen40 write-only,ascii Write text to the LCD screen. Assumes 16/20/40 char width. (Cannot be determined from con‐ troller). version read-only,ascii Self-reported LCD controller version. 16 bytes.


address r_address read-only, ascii The entire 64-bit unique ID. Given as upper case hexadecimal digits (0-9A-F). address starts with the family code r address is the address in reverse order, which is often used in other applications and labeling. crc8 read-only, ascii The 8-bit error correction portion. Uses cyclic redundancy check. Computed from the pre‐ ceding 56 bits of the unique ID number. Given as upper case hexadecimal digits (0-9A-F). family read-only, ascii The 8-bit family code. Unique to each type of device. Given as upper case hexadecimal dig‐ its (0-9A-F). id r_id read-only, ascii The 48-bit middle portion of the unique ID number. Does not include the family code or CRC. Given as upper case hexadecimal digits (0-9A-F). r id is the id in reverse order, which is often used in other applications and labeling. locator r_locator read-only, ascii Uses an extension of the 1-wire design from iButtonLink company that associated 1-wire physical connections with a unique 1-wire code. If the connection is behind a Link Locator the locator will show a unique 8-byte number (16 character hexadecimal) starting with fam‐ ily code FE. If no Link Locator is between the device and the master, the locator field will be all FF. r locator is the locator in reverse order. present (DEPRECATED) read-only, yes-no Is the device currently present on the 1-wire bus? type read-only, ascii Part name assigned by Dallas Semi. E.g. DS2401 Alternative packaging (iButton vs chip) will not be distiguished.


None implemented.


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 sen‐ sors) 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 communi‐ cation. Still the fundemental goal has been ease of use, flexibility and correctness rather than speed. LCD The LCD (3) controller is a microprocessor driven device that simulates the operation of 1-wire devices. It's creator has arbitrarily chosen the family code FF. The controller requires external power. Full details are available from the designer. The main draw of the LCD controller is as any easy way to provide output to users.


All 1-wire devices are factory assigned a unique 64-bit address. This address is of the form: Family Code 8 bits Address 48 bits CRC 8 bits Addressing under OWFS is in hexadecimal, of form: 01.123456789ABC where 01 is an example 8-bit family code, and 12345678ABC is an example 48 bit address. The dot is optional, and the CRC code can included. If included, it must be correct.


Available from


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) EDS0064 (3) EDS0065 (3) EDS0066 (3) EDS0067 (3) EDS0068 (3) EDS0071 (3) EDS0072 (3) MAX31826 (3) Humidity DS1922 (3) DS2438 (3) EDS0065 (3) EDS0068 (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) TAI8570 (3) EDS0066 (3) EDS0068 (3) Moisture EEEF (3) DS2438 (3)



Paul Alfille (
OWFS Manpage 2003 LCD(3)
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Index One-Wire File System (+118) OWFS Manpage (+106) № 3 (+68044)
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