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DS2408(3)		      One-Wire File System		       DS2408(3)

NAME
     DS2408 - 1-Wire 8 Channel Addressable Switch

SYNOPSIS
     8 port switch

     29 	 [.]XXXXXXXXXXXX[XX][/[ 	 latch.[0-7|ALL|BYTE]	       |
     LCD_M/[clear|home|screen|message] |  LCD_H/[clear|home|yxscreen|screen|mes-
     sage|onoff]  |  LCD_H/redefchar.[0-7|ALL]	LCD_H/redefchar_hex.[0-7|ALL]  |
     PIO.[0-7|ALL|BYTE] |  power  |  sensed.[0-7|ALL|BYTE]  |  strobe  |  por  |
     set_alarm	|  out_of_testmode | address | crc8 | id | locator | r_address |
     r_id | r_locator | type ]]

FAMILY CODE
     29

SPECIAL PROPERTIES
   latch.0 ... latch.7 latch.ALL latch.BYTE
     read-write, binary
     The 8 pins (PIO) latch a bit when their state changes,  either  externally,
     or through a write to the pin.
     Reading the latch property indicates that the latch has been set.
     Writing  "true"  (non-zero)  to ANY latch will reset them all. (This is the
     hardware design).
     ALL is all latch states, accessed simultaneously, comma separated.
     BYTE references all channels simultaneously as a single byte. Channel 0  is
     bit 0.

   PIO.0 ... PIO.7 PIO.ALL PIO.BYTE
     read-write, yes-no
     State  of	the open-drain output ( PIO ) pin. 0 = non-conducting (off), 1 =
     conducting (on).
     Writing zero will turn off the switch, non-zero will turn	on  the  switch.
     Reading  the PIO state will return the switch setting. To determine the ac-
     tual logic level  at  the	switch,  refer	to  the  sensed.0  ...	sensed.7
     sensed.ALL sensed.BYTE property.
     ALL references all channels simultaneously, comma separated.
     BYTE  references all channels simultaneously as a single byte. Channel 0 is
     bit 0.

   power
     read-only, yes-no
     Is the DS2408 powered parasitically (0) or separately on the Vcc pin (1)?

   sensed.0 ... sensed.7 sensed.ALL
     read-only, yes-no
     Logic level at the PIO pin. 0 = ground. 1 = high  (~2.4V  -  5V  ).  Really
     makes  sense  only  if  the  PIO state is set to zero (off), else will read
     zero.
     ALL references all channels simultaneously, comma separated.
     BYTE references all channels simultaneously as a single byte. Channel 0  is
     bit 0.

   strobe
     read-write, yes-no
     RSTZ Pin Mode Control. Configures RSTZ as either RST input or STRB output:

     0	    configured as RST input (default)

     1	    configured as STRB output

   por
     read-write, yes-no
     Specifies	whether  the  device  has performed power-on reset. This bit can
     only be cleared to 0 under software control. As long as this bit is  1  the
     device will always respond to a conditional search.

   out_of_testmode
     write-only, yes-no
     Write  "1"  to this property to make sure the device has been properly ini-
     tialized on startup.

     The datasheet says that under some conditions the startup	(power-up)  will
     leave the device in the "testmode" state. Any problems with "Channel Access
     Write" will trigger this property automaticlly, but this property makes ex-
     plicit initialization possible as well.

   set_alarm
     read-write, integer unsigned (0-333333333)
     A number consisting of 9 digits XYYYYYYYY, where:

     X	    select source and logical term
	    0 PIO   OR
	    1 latch OR
	    2 PIO   AND
	    3 latch AND

     Y	    select channel and polarity
	    0 Unselected (LOW)
	    1 Unselected (HIGH)
	    2 Selected	  LOW
	    3 Selected	  HIGH

     All digits will be truncated to the 0-3 range. Leading zeroes are optional.
     Low-order digit is channel 0.

     Example:

     100000033
	    Responds on Conditional Search when latch.1 or latch.0 are set to 1.

     222000000
	    Responds on Conditional Search when sensed.7 and sensed.6 are set to
	    0.

     000000000 (0)
	    Never responds to Conditional Search.

LCD_H LCD SCREEN PROPERITES
     This  mode  uses the DS2408 attached to a Hitachi HD44780 LCD controller in
     4-bit mode. See DATASHEET for published  details.	Based  on  a  commercial
     product from HobbyBoards by Erik Vickery.

   LCD_H/clear
     write-only, yes-no
     This will clear the screen and place the cursor at the start.

   LCD_H/home
     write-only, yes-no
     Positions the cursor in the home (upper left) position, but leaves the cur-
     rent text intact.

   LCD_H/screen
     write-only, ascii text
     Writes to the LCD screen at the current position.

   LCD_H/screenyc
     write-only, ascii text
     Writes  to  an  LCD  screen at a specified location. The controller doesn't
     know the true LCD dimensions, but typical selections are:	2x16  2x20  4x16
     and 4x20.

     Y (row)
	    range 1 to 2 (or 4)

     X (column)
	    range 1 to 16 (or 20)

     There are two formats allowed for the screenyx text, either ascii (readable
     text) or a binary form.

     2 binary bytes
	    The two first characters of the passed string have the line and row:
	    e.g.  "\x02\x04string"  perl string writes "string" at line 2 column
	    4.

     ascii 2,12:
	    Two numbers giving line and row:  Separate with a comma and end with
	    a colon e.g. "2,4:string" writes "string" at line 2 column 4.

     ascii 12:
	    Single column number on the (default) first line:  End with a  colon
	    e.g. "12:string" writes "string" at line 1 column 12.

     The positions are 1-based (i.e. the first position is 1,1).

   LCD_H/onoff
     write-only, unsigned
     Sets several screen display functions. The selected choices should be added
     together.

     4	    Display on

     2	    Cursor on

     1	    Cursor blinking

   LCD_H/message
     write-only, ascii text
     Writes  a	message to the LCD screen after clearing the screen first.  This
     is the easiest way to display a message.

   LCD_H/redefchar.0-7|ALL
     write-only, binary
     Redefines one of 8 user-designed character glyphs for the LCD  screen  (5x8
     pixels).

     Each byte defines a horizontal line top to bottom. All 5 pixels corresponds
     to 0x1F and a blank line is 0x00.

     Format is 8 binary bytes.

   LCD_H/redefchar_hex.0-7|ALL
     write-only, ascii
     Redefines	one  of 8 user-designed character glyphs for the LCD screen (5x8
     pixels).

     Each byte defines a horizontal line top to bottom. All 5 pixels corresponds
     to 0x1F and a blank line is 0x00.

     Format is 8 hexadecimal bytes (16 characters).

LCD_M LCD SCREEN PROPERITES
     This mode uses the DS2408 attached to a Hitachi HD44780 LCD  controller  in
     8-bit  mode.  See	DATASHEET  for published details. Based on a design from
     Maxim and a commercial product from AAG.

   LCD_M/clear
     write-only, yes-no
     This will clear the screen and place the cursor at the start.

   LCD_M/home
     write-only, yes-no
     Positions the cursor in the home (upper left) position, but leaves the cur-
     rent text intact.

   LCD_M/screen
     write-only, ascii text
     Writes to the LCD screen at the current position.

   LCD_M/screenyc
     write-only, ascii text
     Writes to an LCD screen at a specified  location.	The  controller  doesn't
     know  the	true  LCD dimensions, but typical selections are: 2x16 2x20 4x16
     and 4x20.

     Y (row)
	    range 1 to 2 (or 4)

     X (column)
	    range 1 to 16 (or 20)

     There are two formats allowed for the screenyx text, either ascii (readable
     text) or a binary form.

     2 binary bytes
	    The two first characters of the passed string have the line and row:
	    e.g. "\x02\x04string" perl string writes "string" at line  2  column
	    4.

     ascii 2,12:
	    Two numbers giving line and row:  Separate with a comma and end with
	    a colon e.g. "2,4:string" writes "string" at line 2 column 4.

     ascii 12:
	    Single  column number on the (default) first line:	End with a colon
	    e.g. "12:string" writes "string" at line 1 column 12.

     The positions are 1-based (i.e. the first position is 1,1).

   LCD_M/onoff
     write-only, unsigned
     Sets several screen display functions. The selected choices should be added
     together.

     4	    Display on

     2	    Cursor on

     1	    Cursor blinking

   LCD_M/message
     write-only, ascii text
     Writes a message to the LCD screen after clearing the screen  first.   This
     is the easiest way to display a message.

STANDARD PROPERTIES
   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 ap-
     plications and labeling.

   crc8
     read-only, ascii
     The 8-bit error correction portion. Uses cyclic redundancy check.	Computed
     from  the	preceding  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 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 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 asso-
     ciated 1-wire physical connections with a unique 1-wire code. If  the  con-
     nection is behind a Link Locator the locator will show a unique 8-byte num-
     ber (16 character hexadecimal) 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
     Use the set_alarm property to set the alarm triggering criteria.

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-connec-
     tor 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, temper-
     ature,  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  indi-
     vidually 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 con-
     sistent interface. The goal is to provide an easy set of tools for a  soft-
     ware  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	correct-
     ness rather than speed.

   DS2408
     The  DS2408  (3)  allows control of other devices, like LEDs and relays. It
     extends the DS2406 to 8 channels and includes memory.
     Alternative switches include the DS2406, DS2407 and even DS2450

ADDRESSING
     All 1-wire devices are factory assigned a unique 64-bit address.  This  ad-
     dress 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.

DATASHEET
     http://pdfserv.maxim-ic.com/en/ds/DS2408.pdf
     http://www.hobby-boards.com/catalog/howto_lcd_driver.php
     http://www.maxim-ic.com/appnotes.cfm/appnote_number/3286

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)  Infer-
     noEmbedded (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)

AVAILABILITY
     http://www.owfs.org

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

OWFS Manpage			      2003			       DS2408(3)

Want to link to this manual page? Use this URL:
<https://man.freebsd.org/cgi/man.cgi?query=DS2408&sektion=3&manpath=FreeBSD+Ports+15.1.quarterly>

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