DS1904(3)

1DS2415(3)                    One-Wire File System                    DS2415(3)
2
3
4

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
43       DESCRIPTION  for  interpretation.  itime will reflect the interval cho‐
44       sen.
45
46   itime
47       read-write, unsigned integer
48       Interval between timer interrupts. Value in seconds.  See  table  under
49       DESCRIPTION  for  interpretation  and acceptable values.  interval will
50       reflect the itime chosen.
51
52   flags
53       read-write, unsigned integer
54       General use data. 4 bits (0-15 accepted values).
55
56   running
57       read-write, yes-no
58       State of the clock. 0=off 1=running.
59
60   udate
61       read-write, unsigned integer
62       Time represented as a number.  udate increments once per second,  while
63       running is on.
64       Usually set to unix time standard: number of seconds since Jan 1, 1970.
65       The date field will be the unix representation  of  udate  and  setting
66       either will change the other.
67

STANDARD PROPERTIES

69   address
70   r_address
71       read-only, ascii
72       The  entire  64-bit  unique  ID. Given as upper case hexidecimal digits
73       (0-9A-F).
74       address starts with the family code
75       r address is the address in reverse order, which is often used in other
76       applications and labeling.
77
78   crc8
79       read-only, ascii
80       The  8-bit error correction portion. Uses cyclic redundancy check. Com‐
81       puted from the preceding 56 bits of the  unique  ID  number.  Given  as
82       upper case hexidecimal digits (0-9A-F).
83
84   family
85       read-only, ascii
86       The  8-bit  family  code. Unique to each type of device. Given as upper
87       case hexidecimal digits (0-9A-F).
88
89   id
90   r_id
91       read-only, ascii
92       The 48-bit middle portion of the unique ID number. Does not include the
93       family code or CRC. Given as upper case hexidecimal digits (0-9A-F).
94       r  id is the id in reverse order, which is often used in other applica‐
95       tions and labeling.
96
97   locator
98   r_locator
99       read-only, ascii
100       Uses an extension of the 1-wire design from  iButtonLink  company  that
101       associated  1-wire  physical  connections with a unique 1-wire code. If
102       the connection is behind a Link Locator the locator will show a  unique
103       8-byte number (16 character hexidecimal) starting with family code FE.
104       If  no  Link  Locator is between the device and the master, the locator
105       field will be all FF.
106       r locator is the locator in reverse order.
107
108   present (DEPRECATED)
109       read-only, yes-no
110       Is the device currently present on the 1-wire bus?
111
112   type
113       read-only, ascii
114       Part name assigned by Dallas Semi. E.g.  DS2401  Alternative  packaging
115       (iButton vs chip) will not be distiguished.
116

ALARMS

118       None implemented.
119

DESCRIPTION

121   1-Wire
122       1-wire is a wiring protocol and series of devices designed and manufac‐
123       tured by Dallas Semiconductor, Inc. The bus is  a  low-power  low-speed
124       low-connector scheme where the data line can also provide power.
125
126       Each  device  is  uniquely and unalterably numbered during manufacture.
127       There are a wide variety of devices, including memory, sensors  (humid‐
128       ity, temperature, voltage, contact, current), switches, timers and data
129       loggers. More complex devices (like thermocouple sensors) can be  built
130       with  these  basic  devices.  There  are  also 1-wire devices that have
131       encryption included.
132
133       The 1-wire scheme uses a single bus master and multiple slaves  on  the
134       same  wire.  The bus master initiates all communication. The slaves can
135       be individually discovered and addressed using their unique ID.
136
137       Bus masters come in a variety of configurations including serial,  par‐
138       allel, i2c, network or USB adapters.
139
140   OWFS design
141       OWFS  is  a  suite of programs that designed to make the 1-wire bus and
142       its devices easily accessible. The underlying principle is to create  a
143       virtual  filesystem,  with  the  unique ID being the directory, and the
144       individual properties of the device are  represented  as  simple  files
145       that can be read and written.
146
147       Details  of  the  individual slave or master design are hidden behind a
148       consistent interface. The goal is to provide an easy set of tools for a
149       software  designer  to create monitoring or control applications. There
150       are some performance enhancements in the implementation, including data
151       caching, parallel access to bus masters, and aggregation of device com‐
152       munication. Still the fundemental goal has been ease of use,  flexibil‐
153       ity and correctness rather than speed.
154
155   DS2415 DS1904
156       The DS2415 (3) and DS1904 (3) are simple clocks that can be read on the
157       1-wire bus. They can also be used the time an event, for remote confir‐
158       mation.
159
160   DS2417
161       The  DS2417  has  the same clock function, but also includes a program‐
162       mable interval interrupt. Values Allowed are:
163       0 1sec
164       1 4sec
165       2 32s = .5m
166       3 6 = 1m
167       4 2048s = .5h
168       5 4096s = 1h
169       6 65536s = 18h
170       7 131072s = 36h
171

ADDRESSING

173       All 1-wire devices are factory assigned a unique 64-bit  address.  This
174       address is of the form:
175
176       Family Code
177              8 bits
178
179       Address
180              48 bits
181
182       CRC    8 bits
183
184       Addressing under OWFS is in hexidecimal, of form:
185
186              01.123456789ABC
187
188       where 01 is an example 8-bit family code, and 12345678ABC is an example
189       48 bit address.
190
191       The dot is optional, and the CRC code can  included.  If  included,  it
192       must be correct.
193

DATASHEET

195       http://pdfserv.maxim-ic.com/en/ds/DS2415.pdf
196       http://pdfserv.maxim-ic.com/en/ds/DS1904.pdf
197       http://pdfserv.maxim-ic.com/en/ds/DS2417.pdf
198

AVAILABILITY

260       http://www.owfs.org
261

AUTHOR

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