'\"
'\" Copyright (c) 2003-2004 Paul H Alfille, MD
'\" (paul.alfille@gmail.com)
'\"
'\" Device manual page for the OWFS -- 1-wire filesystem package
'\" Based on Dallas Semiconductor, Inc's datasheets, and trial and error.
'\"
'\" Free for all use. No warranty. None. Use at your own risk.
'\"
.TH DS2450 3  2003 "OWFS Manpage" "One-Wire File System"
.SH NAME
.B DS2450
\- Quad A/D Converter
.SH SYNOPSIS
.SS Voltage * 4  and Memory.
.PP
.B 20
[.]XXXXXXXXXXXX[XX][/[
.B PIO.[A-D|ALL]
|
.B volt.[A-D|ALL]
|
.B volt2.[A-D|ALL]
|
.B latestvolt.[A-D|ALL]
|
.B latestvolt2.[A-D|ALL]
]]
.PP
.B 20
[.]XXXXXXXXXXXX[XX][/[
.B 8bit/volt.[A-D|ALL]
|
.B 8bit/volt2.[A-D|ALL]
|
.B 8bit/latestvolt.[A-D|ALL]
|
.B 8bit/latestvolt2.[A-D|ALL]
]]
.PP
.B 20
[.]XXXXXXXXXXXX[XX][/[
.B memory
|
.B pages/page.[0-3|ALL]
|
.B power
]
.PP
.B 20
[.]XXXXXXXXXXXX[XX][/[
.B alarm/high.[A-D|ALL]
|
.B alarm/low.[A-D|ALL]
|
.B set_alarm/high.[A-D|ALL]
|
.B set_alarm/low.[A-D|ALL]
|
.B set_alarm/unset
|
.B set_alarm/volthigh.[A-D|ALL]
|
.B set_alarm/volt2high.[A-D|ALL]
|
.B set_alarm/voltlow.[A-D|ALL]
|
.B set_alarm/volt2low.[A-D|ALL]
]
.PP
.B 20
[.]XXXXXXXXXXXX[XX][/[
'\"
'\" Copyright (c) 2003-2004 Paul H Alfille, MD
'\" (paul.alfille@gmail.com)
'\"
'\" Program manual page for the OWFS -- 1-wire filesystem package
'\" Based on Dallas Semiconductor, Inc's datasheets, and trial and error.
'\"
'\" Free for all use. No warranty. None. Use at your own risk.
'\"
.B address
|
.B crc8
|
.B id
|
.B locator
|
.B r_address
|
.B r_id
|
.B r_locator
|
.B type
]]
.SS CO2 sensor
.PP
.B 20
[.]XXXXXXXXXXXX[XX][/[
.B CO2/ppm
|
.B CO2/power
|
.B CO2/status
]
.SH FAMILY CODE
.PP
.I 20
.SH SPECIAL PROPERTIES
.SS alarm/high.A ... alarm/high.D alarm.high.ALL
.SS alarm/high.A ... alarm/high.D alarm.high.ALL
.I read-write, binary
.br
The alarm state of the voltage channel. The alarm state is set one of two ways:
.TP
voltage conversion
Whenever the
.I DS2450
measures a voltage on a channel, that voltage is compared to the high and low limits
.I set_alarm/volthigh
and/or
.I set_alarm/voltlow
and if the alarm is enabled
.I set_alarm/high
and/or
.I set_alarm/low
the corresponding flag is set in
.I alarm/high
and/or
.I alarm/low
.TP
manual set
The flag can be set by a direct write to
.I alarm/high
or
.I alarm/low
.SS memory
.I read-write, binary
.br
32 bytes of data. Much has special implications. See the datasheet.
.SS pages/page.0 ... pages/page.3 pages/page.ALL
.I read-write, binary
.br
Memory is split into 4 pages of 8 bytes each. Mostly for reading and setting device properties. See the datasheet for details.
.br
.I ALL
is an aggregate of the pages. Each page is accessed sequentially.
.SS PIO.A ... PIO.D PIO.ALL
.I read-write, yes-no
.br
Pins used for digital control. 1 turns the switch on (conducting). 0 turns the switch off (non-conducting).
.br
Control is specifically enabled. Reading
.I volt
will turn off this control.
.br
.I ALL
is an aggregate of the voltages. Readings are made separately.
.SS power
.I read-write, yes-no
.br
Configure whether the
.I DS2450
is externally powered (as opposed to parasitically powered from the data line).
.br
If configured as powered, the A/D coverter will be set to continuous sampling, and the bus will be released during a single conversion allowing other devices to communicate.
.br
Setting this to 1 when no power is applied to the chip's Vcc will result in wrong voltage readouts.
Setting this to 0 when power is applied to the chip's Vcc allows a simultaneous conversion trigger on all
.I DS2450
on a bus. The (always safe) default is 0.
.SS set_alarm/high.A ... set_alarm/high.D set_alarm/high.ALL
.SS set_alarm/low.A ... set_alarm/low.D set_alarm/low.ALL
.I read-write, yes-no
.br
Enabled status of the voltage threshold. 1 is on. 0 is off.
.SS set_alarm/volthigh.A ... set_alarm/volthigh.D set_alarm/volthigh.ALL
.SS set_alarm/volt2high.A ... set_alarm/volt2high.D set_alarm/volt2high.ALL
.SS set_alarm/voltlow.A ... set_alarm/voltlow.D set_alarm/voltlow.ALL
.SS set_alarm/volt2low.A ... set_alarm/volt2low.D set_alarm/volt2low.ALL
.I read-write, floating point
.br
The upper or lower limit for the voltage measured before triggering an alarm.
.br
Note that the alarm must be enabled
.I alarm/high
or
.I alarm.low
and an actual reading must be requested
.I volt
for the alarm state to actually be set. The alarm state can be sensed at
.I alarm/high
and
.I alarm/low
.SS set_alarm/unset
.I read-write, yes-no
.br
Status of the power-on-reset (POR) flag.
.br
The POR is set when the
.I DS2450
is first powered up, and will match the alarm state until explicitly cleared. (By writing 0 to it).
.br
The purpose of the POR is to alert the user that the chip is not yet fully configured, especially alarm thresholds and enabling.
.SS volt.A ... volt.D volt.ALL
.SS volt2.A ... volt2.D volt2.ALL
.SS 8bit/volt.A ... 8bit/volt.D 8bit/volt.ALL
.SS 8bit/volt2.A ... 8bit/volt2.D 8bit/volt2.ALL
.I read-only, floating point
.br
Reading one of these nodes triggers a conversion on the specified voltage 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 (
.I PIO
) is disabled by reading the corresponding node.
.br
.I 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.
.SS latestvolt.A ... latestvolt.D latestvolt.ALL
.SS latestvolt2.A ... latestvolt2.D latestvolt2.ALL
.SS 8bit/latestvolt.A ... 8bit/latestvolt.D 8bit/latestvolt.ALL
.SS 8bit/latestvolt2.A ... 8bit/latestvolt2.D 8bit/latestvolt2.ALL
.I read-only, floating point
.br
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.
.br
.I ALL
is an aggregate of the voltages and returns all voltage values from the chip.
.br
Reading these nodes will never trigger a voltage conversion. Intended for use in conjunction with
.B /simultaneous/voltage.
.SH CO2 (Carbon Dioxide) SENSOR PROPERTIES
The CO2 sensor is a device constructed from a SenseAir K30 and a
.I DS2450
.SS CO2/power
.I read-only, floating point
.br
Supply voltage to the CO2 sensor (should be around 5V)
.SS CO2/ppm
.I read-only, unsigned
.br
CO2 level in ppm (parts per million). Range 0-5000.
.SS CO2/status
.I read-only, yes-no
.br
Is the internal voltage correct (around 3.2V)?
.SH STANDARD PROPERTIES
'\"
'\" Copyright (c) 2003-2004 Paul H Alfille, MD
'\" (paul.alfille@gmail.com)
'\"
'\" Program manual page for the OWFS -- 1-wire filesystem package
'\" Based on Dallas Semiconductor, Inc's datasheets, and trial and error.
'\"
'\" Free for all use. No warranty. None. Use at your own risk.
'\"
.SS address
.SS r_address
.I read-only, ascii
.br
The entire 64-bit unique ID. Given as upper case hexadecimal digits (0-9A-F).
.br
.I address
starts with the
.I family
code
.br
.I r address
is the
.I address
in reverse order, which is often used in other applications and labeling.
.SS crc8
.I read-only, ascii
.br
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).
.SS family
.I read-only, ascii
.br
The 8-bit family code. Unique to each
.I type
of device. Given as upper case hexadecimal digits (0-9A-F).
.SS id
.SS r_id
.I read-only, ascii
.br
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).
.br
.I r id
is the
.I id
in reverse order, which is often used in other applications and labeling.
.SS locator
.SS r_locator
.I read-only, ascii
.br
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
.B Link Locator
the
.I locator will show a unique 8-byte number (16 character hexadecimal) starting with family code FE.
.br
If no
.B Link Locator
is between the device and the master, the
.I locator
field will be all FF.
.br
.I r locator
is the
.I locator
in reverse order.
.SS present (DEPRECATED)
.I read-only, yes-no
.br
Is the device currently
.I present
on the 1-wire bus?
.SS type
.I read-only, ascii
.br
Part name assigned by Dallas Semi. E.g.
.I DS2401
Alternative packaging (iButton vs chip) will not be distiguished.
.SH ALARMS
None.
.SH DESCRIPTION
'\"
'\" Copyright (c) 2003-2004 Paul H Alfille, MD
'\" (paul.alfille@gmail.com)
'\"
'\" Program manual page for the OWFS -- 1-wire filesystem package
'\" Based on Dallas Semiconductor, Inc's datasheets, and trial and error.
'\"
'\" Free for all use. No warranty. None. Use at your own risk.
'\"
.SS 1-Wire
.I 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.
.PP
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.
.PP
The 1-wire scheme uses a single 
.I bus master
and multiple
.I slaves
on the same wire. The bus master initiates all communication. The slaves can be 
individually discovered and addressed using their unique ID.
.PP
Bus masters come in a variety of configurations including serial, parallel, i2c, network or USB
adapters.
.SS OWFS design
.I 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.
.PP 
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 fundamental goal has been ease of use, flexibility
and correctness rather than speed.
.SS DS2450
The
.B 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 current, but sometimes restricted voltrage ranges) can also be obtained with the
.B DS2436
,
.B DS2438
and
.B DS276x
.SH ADDRESSING
'\"
'\" Copyright (c) 2003-2004 Paul H Alfille, MD
'\" (paul.alfille@gmail.com)
'\"
'\" Program manual page for the OWFS -- 1-wire filesystem package
'\" Based on Dallas Semiconductor, Inc's datasheets, and trial and error.
'\"
'\" Free for all use. No warranty. None. Use at your own risk.
'\"
All 1-wire devices are factory assigned a unique 64-bit address. This address is of the form:
.TP
.B Family Code
8 bits
.TP
.B Address
48 bits
.TP
.B CRC
8 bits
.IP
.PP
Addressing under OWFS is in hexadecimal, of form:
.IP
.B 01.123456789ABC
.PP
where
.B 01
is an example 8-bit family code, and
.B 12345678ABC
is an example 48 bit address.
.PP
The dot is optional, and the CRC code can included. If included, it must be correct.
.SH DATASHEET
.TP
DS2450
http://pdfserv.maxim-ic.com/en/ds/DS2450.pdf
.TP
CO2 sensor
http://www.senseair.se/Datablad/k30%20.pdf
.TP 
CO2 device
https://www.m.nu/co2meter-version-2-p-259.html?language=en
.SH SEE ALSO
.SS Programs
.B owfs (1) owhttpd (1) owftpd (1) owserver (1)
.B owdir (1) owread (1) owwrite (1) owpresent (1)
.B owtap (1)
.SS Configuration and testing
.B owfs (5) owtap (1) owmon (1)
.SS Language bindings
.B owtcl (3) owperl (3) owcapi (3)
.SS Clocks
.B DS1427 (3) DS1904 (3) DS1994 (3) DS2404 (3) DS2404S (3) DS2415 (3) DS2417 (3)
.SS ID
.B DS2401 (3) DS2411 (3) DS1990A (3)
.SS Memory
.B 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)
.SS Switches
.B DS2405 (3) DS2406 (3) DS2408 (3) DS2409 (3) DS2413 (3) DS28EA00 (3)
.SS Temperature
.B 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)
.SS Humidity
.B DS1922 (3) DS2438 (3) EDS0065 (3) EDS0068 (3)
.SS Voltage
.B DS2450 (3)
.SS Resistance
.B DS2890 (3)
.SS Multifunction (current, voltage, temperature)
.B DS2436 (3) DS2437 (3) DS2438 (3) DS2751 (3) DS2755 (3) DS2756 (3) DS2760 (3) DS2770 (3) DS2780 (3) DS2781 (3) DS2788 (3) DS2784 (3)
.SS Counter
.B DS2423 (3)
.SS LCD Screen
.B LCD (3) DS2408 (3)
.SS Crypto
.B DS1977 (3)
.SS Pressure
.B DS2406 (3) TAI8570 (3) EDS0066 (3) EDS0068 (3)
.SS Moisture
.B EEEF (3) DS2438 (3)
.SH AVAILABILITY
http://www.owfs.org
.SH AUTHOR
Paul Alfille (paul.alfille@gmail.com)