DS1904(3)

1DS2415(3)                    One-Wire File System                    DS2415(3)
2
3
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NAME

6       DS2415,  DS1904, DS2417 - 1-Wire Time Chip, RTC (real time clock) iBut‐
7       ton, 1-Wire Time Chip with Interrupt
8

SYNOPSIS

10       Real time clock.
11       24 [.]XXXXXXXXXXXX[XX][/[ date | flags | running | udate  |  address  |
12       crc8 | id | locator | r_address | r_id | r_locator | type ]]
13
14       Clock with interrupts
15       27  [.]XXXXXXXXXXXX[XX][/[ date | enable | interval | itime | running |
16       udate | address | crc8 | id | locator | r_address | r_id | r_locator  |
17       type ]]
18

FAMILY CODE

20       24     DS2415 DS1904
21
22       27     DS2417
23

SPECIAL PROPERTIES

25   date
26       read-write, ascii
27       26  character date representation of the counter value. Increments once
28       per second while running
29       Setting date to a null string will put the current system time.
30       Accepted date formats are:
31         Sat[urday] March 12 12:23:59 2001
32         Apr[il] 4 9:34:56 2002
33         3/23/04 23:34:57
34         current locale setting (your system's format)
35
36   enable
37       read-write, yes-no
38       State of the timer interrupt. 0=off 1=running.
39
40   interval
41       read-write, unsigned integer
42       Interval between timer interrupts. Values: 0-7.  See  table  under  DE‐
43       SCRIPTION for interpretation.  itime will reflect the interval chosen.
44
45   itime
46       read-write, unsigned integer
47       Interval  between  timer  interrupts. Value in seconds. See table under
48       DESCRIPTION for interpretation and acceptable  values.   interval  will
49       reflect the itime chosen.
50
51   flags
52       read-write, unsigned integer
53       General use data. 4 bits (0-15 accepted values).
54
55   running
56       read-write, yes-no
57       State of the clock. 0=off 1=running.
58
59   udate
60       read-write, unsigned integer
61       Time  represented as a number.  udate increments once per second, while
62       running is on.
63       Usually set to unix time standard: number of seconds since Jan 1, 1970.
64       The date field will be the unix representation of udate and setting ei‐
65       ther will change the other.
66

STANDARD PROPERTIES

68   address
69   r_address
70       read-only, ascii
71       The entire 64-bit unique ID. Given as  upper  case  hexadecimal  digits
72       (0-9A-F).
73       address starts with the family code
74       r address is the address in reverse order, which is often used in other
75       applications and labeling.
76
77   crc8
78       read-only, ascii
79       The 8-bit error correction portion. Uses cyclic redundancy check.  Com‐
80       puted  from the preceding 56 bits of the unique ID number. Given as up‐
81       per case hexadecimal digits (0-9A-F).
82
83   family
84       read-only, ascii
85       The 8-bit family code. Unique to each type of device.  Given  as  upper
86       case hexadecimal digits (0-9A-F).
87
88   id
89   r_id
90       read-only, ascii
91       The 48-bit middle portion of the unique ID number. Does not include the
92       family code or CRC. Given as upper case hexadecimal digits (0-9A-F).
93       r id is the id in reverse order, which is often used in other  applica‐
94       tions and labeling.
95
96   locator
97   r_locator
98       read-only, ascii
99       Uses  an  extension  of the 1-wire design from iButtonLink company that
100       associated 1-wire physical connections with a unique  1-wire  code.  If
101       the  connection is behind a Link Locator the locator will show a unique
102       8-byte number (16 character hexadecimal) starting with family code FE.
103       If no Link Locator is between the device and the  master,  the  locator
104       field will be all FF.
105       r locator is the locator in reverse order.
106
107   present (DEPRECATED)
108       read-only, yes-no
109       Is the device currently present on the 1-wire bus?
110
111   type
112       read-only, ascii
113       Part  name  assigned by Dallas Semi. E.g.  DS2401 Alternative packaging
114       (iButton vs chip) will not be distiguished.
115

ALARMS

117       None implemented.
118

DESCRIPTION

120   1-Wire
121       1-wire is a wiring protocol and series of devices designed and manufac‐
122       tured  by  Dallas  Semiconductor, Inc. The bus is a low-power low-speed
123       low-connector scheme where the data line can also provide power.
124
125       Each device is uniquely and unalterably  numbered  during  manufacture.
126       There  are a wide variety of devices, including memory, sensors (humid‐
127       ity, temperature, voltage, contact, current), switches, timers and data
128       loggers.  More complex devices (like thermocouple sensors) can be built
129       with these basic devices. There are also 1-wire devices that  have  en‐
130       cryption included.
131
132       The  1-wire  scheme uses a single bus master and multiple slaves on the
133       same wire. The bus master initiates all communication. The  slaves  can
134       be individually discovered and addressed using their unique ID.
135
136       Bus  masters come in a variety of configurations including serial, par‐
137       allel, i2c, network or USB adapters.
138
139   OWFS design
140       OWFS is a suite of programs that designed to make the  1-wire  bus  and
141       its  devices easily accessible. The underlying principle is to create a
142       virtual filesystem, with the unique ID being the directory, and the in‐
143       dividual  properties of the device are represented as simple files that
144       can be read and written.
145
146       Details of the individual slave or master design are  hidden  behind  a
147       consistent interface. The goal is to provide an easy set of tools for a
148       software designer to create monitoring or control  applications.  There
149       are some performance enhancements in the implementation, including data
150       caching, parallel access to bus masters, and aggregation of device com‐
151       munication.  Still the fundamental goal has been ease of use, flexibil‐
152       ity and correctness rather than speed.
153
154   DS2415 DS1904
155       The DS2415 (3) and DS1904 (3) are simple clocks that can be read on the
156       1-wire bus. They can also be used the time an event, for remote confir‐
157       mation.
158
159   DS2417
160       The DS2417 has the same clock function, but also  includes  a  program‐
161       mable interval interrupt. Values Allowed are:
162       0 1sec
163       1 4sec
164       2 32s = .5m
165       3 6 = 1m
166       4 2048s = .5h
167       5 4096s = 1h
168       6 65536s = 18h
169       7 131072s = 36h
170

ADDRESSING

172       All  1-wire  devices are factory assigned a unique 64-bit address. This
173       address is of the form:
174
175       Family Code
176              8 bits
177
178       Address
179              48 bits
180
181       CRC    8 bits
182
183       Addressing under OWFS is in hexadecimal, of form:
184
185              01.123456789ABC
186
187       where 01 is an example 8-bit family code, and 12345678ABC is an example
188       48 bit address.
189
190       The  dot  is  optional,  and the CRC code can included. If included, it
191       must be correct.
192

DATASHEET

194       http://pdfserv.maxim-ic.com/en/ds/DS2415.pdf
195       http://pdfserv.maxim-ic.com/en/ds/DS1904.pdf
196       http://pdfserv.maxim-ic.com/en/ds/DS2417.pdf
197

AVAILABILITY

260       http://www.owfs.org
261

AUTHOR

263       Paul Alfille (paul.alfille@gmail.com)
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267OWFS Manpage                         2003                            DS2415(3)