Skip site navigation (1)Skip section navigation (2)

FreeBSD Manual Pages

  
 
  

home | help
LCD(3)			     One-Wire File System			LCD(3)

NAME
       LCD - LCD controller

SYNOPSIS
       1-wire LCD controller by	Louis Swart

       FF  [.]XXXXXXXXXXXX[XX][/[  backlight  |	 counters.[0-3|ALL]  | cumula-
       tive.[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	| reg-
       ister | screen16	| screen20 | screen40 |	version	| address | crc8 |  id
       | locator | r_address | r_id | r_locator	| type ]]

FAMILY CODE
       FF

SPECIAL	PROPERTIES
   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 property instead.
       ALL  is	an  aggregate  of the properties, comma	separated. Read	atomi-
       cally.

   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 preserva-
       tion of counts accross program restarts if the value at program	termi-
       nation 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 coun-
       ters can	be interspersed	without	losing 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 controller).
       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 controller).

   version
       read-only,ascii
       Self-reported LCD controller version. 16	bytes.

STANDARD PROPERTIES
   address
   r_address
       read-only, ascii
       The  entire  64-bit  unique  ID.	Given as upper case hexidecimal	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. Com-
       puted from the preceding	56 bits	of the unique ID number. Given as  up-
       per case	hexidecimal digits (0-9A-F).

   family
       read-only, ascii
       The  8-bit  family  code. Unique	to each	type of	device.	Given as upper
       case hexidecimal	digits (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 hexidecimal digits (0-9A-F).
       r  id is	the id in reverse order, which is often	used in	other applica-
       tions 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 hexidecimal)	starting with family 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.

ALARMS
       None implemented.

DESCRIPTION
   1-Wire
       1-wire is a wiring protocol and series of devices designed and manufac-
       tured 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  (humid-
       ity, 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 en-
       cryption	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,  par-
       allel, 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 in-
       dividual	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 com-
       munication. Still the fundemental goal has been ease of use,  flexibil-
       ity 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 de-
       tails are available from	the designer.
       The main	draw of	the LCD	controller is as any easy way to provide  out-
       put to users.

ADDRESSING
       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 hexidecimal,	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.

DATASHEET
       Available from http://www.louisswart.co.za/1-Wire_index.html

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) 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 EDS0066 (3) EDS0068 (3)

   Moisture
       EEEF (3)	DS2438 (3)

AVAILABILITY
       http://www.owfs.org

AUTHOR
       Paul Alfille (paul.alfille@gmail.com)

OWFS Manpage			     2003				LCD(3)

NAME | SYNOPSIS | FAMILY CODE | SPECIAL PROPERTIES | STANDARD PROPERTIES | ALARMS | DESCRIPTION | ADDRESSING | DATASHEET | SEE ALSO | AVAILABILITY | AUTHOR

Want to link to this manual page? Use this URL:
<https://www.freebsd.org/cgi/man.cgi?query=LCD&sektion=3&manpath=FreeBSD+12.0-RELEASE+and+Ports>

home | help