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DS2450(3)		     One-Wire File System		     DS2450(3)

NAME
       DS2450 -	Quad A/D Converter

SYNOPSIS
   Voltage * 4 and Memory.
       20  [.]XXXXXXXXXXXX[XX][/[  PIO.[A-D|ALL]  | volt.[A-D|ALL] | volt2.[A-
       D|ALL] |	latestvolt.[A-D|ALL] | latestvolt2.[A-D|ALL] ]]

       20 [.]XXXXXXXXXXXX[XX][/[ 8bit/volt.[A-D|ALL] | 8bit/volt2.[A-D|ALL]  |
       8bit/latestvolt.[A-D|ALL] | 8bit/latestvolt2.[A-D|ALL] ]]

       20 [.]XXXXXXXXXXXX[XX][/[ memory	| pages/page.[0-3|ALL] | power ]

       20  [.]XXXXXXXXXXXX[XX][/[ alarm/high.[A-D|ALL] | alarm/low.[A-D|ALL] |
       set_alarm/high.[A-D|ALL]	| set_alarm/low.[A-D|ALL] | set_alarm/unset  |
       set_alarm/volthigh.[A-D|ALL]    |    set_alarm/volt2high.[A-D|ALL]    |
       set_alarm/voltlow.[A-D|ALL] | set_alarm/volt2low.[A-D|ALL] ]

       20 [.]XXXXXXXXXXXX[XX][/[ address | crc8	| id | locator |  r_address  |
       r_id | r_locator	| type ]]

   CO2 sensor
       20 [.]XXXXXXXXXXXX[XX][/[ CO2/ppm | CO2/power | CO2/status ]

FAMILY CODE
       20

SPECIAL	PROPERTIES
   alarm/high.A	... alarm/high.D alarm.high.ALL
   alarm/high.A	... alarm/high.D alarm.high.ALL
       read-write, binary
       The  alarm  state of the	voltage	channel. The alarm state is set	one of
       two ways:

       voltage conversion
	      Whenever the DS2450 measures a voltage on	a channel, that	 volt-
	      age  is  compared	 to the	high and low limits set_alarm/volthigh
	      and/or  set_alarm/voltlow	 and   if   the	  alarm	  is   enabled
	      set_alarm/high  and/or  set_alarm/low  the corresponding flag is
	      set in alarm/high	and/or alarm/low

       manual set
	      The flag can be set by a direct write to alarm/high or alarm/low

   memory
       read-write, binary
       32 bytes	of data. Much has special implications.	See the	datasheet.

   pages/page.0	... pages/page.3 pages/page.ALL
       read-write, binary
       Memory is split into 4 pages of 8 bytes each. Mostly  for  reading  and
       setting device properties. See the datasheet for	details.
       ALL is an aggregate of the pages. Each page is accessed sequentially.

   PIO.A ... PIO.D PIO.ALL
       read-write, yes-no
       Pins  used  for	digital	control. 1 turns the switch on (conducting). 0
       turns the switch	off (non-conducting).
       Control is specifically enabled.	Reading	volt will turn off  this  con-
       trol.
       ALL is an aggregate of the voltages. Readings are made separately.

   power
       read-write, yes-no
       Configure whether the DS2450 is externally powered (as opposed to para-
       sitically powered from the data line).
       If configured as	powered, the A/D coverter will be  set	to  continuous
       sampling,  and  the bus will be released	during a single	conversion al-
       lowing other devices to communicate.
       Setting this to 1 when no power is applied to the chip's	Vcc  will  re-
       sult  in	 wrong	voltage	readouts.  Setting this	to 0 when power	is ap-
       plied to	the chip's Vcc allows a	simultaneous conversion	trigger	on all
       DS2450 on a bus.	The (always safe) default is 0.

   set_alarm/high.A ...	set_alarm/high.D set_alarm/high.ALL
   set_alarm/low.A ... set_alarm/low.D set_alarm/low.ALL
       read-write, yes-no
       Enabled status of the voltage threshold.	1 is on. 0 is off.

   set_alarm/volthigh.A	... set_alarm/volthigh.D set_alarm/volthigh.ALL
   set_alarm/volt2high.A ... set_alarm/volt2high.D set_alarm/volt2high.ALL
   set_alarm/voltlow.A ... set_alarm/voltlow.D set_alarm/voltlow.ALL
   set_alarm/volt2low.A	... set_alarm/volt2low.D set_alarm/volt2low.ALL
       read-write, floating point
       The  upper or lower limit for the voltage measured before triggering an
       alarm.
       Note that the alarm must	be enabled alarm/high or alarm.low and an  ac-
       tual  reading must be requested volt for	the alarm state	to actually be
       set. The	alarm state can	be sensed at alarm/high	and alarm/low

   set_alarm/unset
       read-write, yes-no
       Status of the power-on-reset (POR) flag.
       The POR is set when the DS2450 is first powered up, and will match  the
       alarm state until explicitly cleared. (By writing 0 to it).
       The  purpose  of	 the POR is to alert the user that the chip is not yet
       fully configured, especially alarm thresholds and enabling.

   volt.A ... volt.D volt.ALL
   volt2.A ... volt2.D volt2.ALL
   8bit/volt.A ... 8bit/volt.D 8bit/volt.ALL
   8bit/volt2.A	... 8bit/volt2.D 8bit/volt2.ALL
       read-only, floating point
       Reading one of these nodes triggers a conversion	on the specified volt-
       age input(s) with the selected resolution (16 or	8 bit) and returns the
       sampled voltage(s) with the selected scaling (0 - 5.10V or 0 -  2.55V).
       The  conversion	time is	about 1.4ms per	input for 16-bit and 0.8ms per
       input for 8-bit.	 The output feature ( PIO ) is disabled	by reading the
       corresponding node.
       ALL is an aggregate of the voltages. Sampling is	controlled by the chip
       and done	in the order A,	B, C, D, one after another.

   latestvolt.A	... latestvolt.D latestvolt.ALL
   latestvolt2.A ... latestvolt2.D latestvolt2.ALL
   8bit/latestvolt.A ... 8bit/latestvolt.D 8bit/latestvolt.ALL
   8bit/latestvolt2.A ... 8bit/latestvolt2.D 8bit/latestvolt2.ALL
       read-only, floating point
       Returns previously measured voltage on the specified input(s) with  the
       selected	 scaling (0 - 5.10V or 0 - 2.55V).  Resolution and scaling are
       set by sampling a voltage, not here; the	correct	latestvolt nodes  have
       to be read to make the result meaningful.
       ALL is an aggregate of the voltages and returns all voltage values from
       the chip.
       Reading these nodes will	never trigger a	voltage	 conversion.  Intended
       for use in conjunction with /simultaneous/voltage.

CO2 (Carbon Dioxide) SENSOR PROPERTIES
       The CO2 sensor is a device constructed from a SenseAir K30 and a	DS2450

   CO2/power
       read-only, floating point
       Supply voltage to the CO2 sensor	(should	be around 5V)

   CO2/ppm
       read-only, unsigned
       CO2 level in ppm	(parts per million). Range 0-5000.

   CO2/status
       read-only, yes-no
       Is the internal voltage correct (around 3.2V)?

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
       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	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 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 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
       None.

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 principle 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 fundamental goal has been ease of use,  flexibil-
       ity and correctness rather than speed.

   DS2450
       The  DS2450  (3)	is a (supposedly) high resolution A/D converter	with 4
       channels. Actual	resolutin is reporterd to be 8 bits. The channels  can
       also  function  as switches. Voltage sensing (with temperature and cur-
       rent, but sometimes restricted voltrage ranges) can  also  be  obtained
       with the	DS2436 , DS2438	and DS276x

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 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
       DS2450 http://pdfserv.maxim-ic.com/en/ds/DS2450.pdf

       CO2 sensor
	      http://www.senseair.se/Datablad/k30%20.pdf

       CO2 device
	      https://www.m.nu/co2meter-version-2-p-259.html?language=en

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) In-
       fernoEmbedded (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			     DS2450(3)

NAME | SYNOPSIS | FAMILY CODE | SPECIAL PROPERTIES | CO2 (Carbon Dioxide) SENSOR PROPERTIES | STANDARD PROPERTIES | ALARMS | DESCRIPTION | ADDRESSING | DATASHEET | SEE ALSO | AVAILABILITY | AUTHOR

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