DS2505(3)

💖 DS2505(3) — One-Wire File System 💖

okay bestie, gather round, because we're about to get SO acquainted with a little chip from the One-Wire File System (that's the OWFS manual, section 3, for the record 🫶). this is your girl's guide to the add-only memory girlies and their iButton cousins. no cap, every single detail is staying. periodt. 💅

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✨ NAME ✨

DS2505, DS2505-UNW — Add-Only Memory (16 kBit), UniqueWare Add-Only Memory (16 kBit) 💾

DS1985, DS1985U — Add-Only iButton (16 kBit), UniqueWare iButton (16 kBit) 🎀

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✨ SYNOPSIS ✨

EPROM add-only memory. that's the whole vibe. ✨

0B [.]XXXXXXXXXXXX[XX][/[ memory | pages/page.[0-63|ALL] | address |
crc8 | id | locator | r_address | r_id | r_locator | type ]]

8B [.]XXXXXXXXXXXX[XX][/[ memory | pages/page.[0-63|ALL] | address |
crc8 | id | locator | r_address | r_id | r_locator | type ]]

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✨ FAMILY CODE ✨

• 0B — DS2505 DS1985
• 8B — DS2505-UNW DS1985U

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✨ SPECIAL PROPERTIES ✨

memory

read-write, binary 🌸

2048 bytes of memory, bestie. and here's the tea: initially all bits are set to 1. writing zero permanently alters the memory. permanent. like a tweet screenshot. so be careful, okay? 🫶

pages/page.0 ... pages/page.63 pages/page.ALL

read-write, yes-no 🦋

the memory is split into 64 pages of 32 bytes each. ALL is an aggregate of the pages — one big mood that contains all the little moods. each page is accessed sequentially, so no cutting the line. 🎀

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✨ 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 (that's r address when your terminal is being shy about the underscore) is the address in reverse order, which is often used in other applications and labeling. it's giving backwards-but-make-it-fashun. 💅

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). she's the bouncer at the club, checking everyone's ID. 👑

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. (yes, the manpage says r id with a space there, we don't question the ancestors. 🙈)

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. it's giving GPS but for wires. 📍

present (DEPRECATED)

read-only, yes-no 💀

is the device currently present on the 1-wire bus?

heads up bestie: this one is DEPRECATED. she's still in the group chat but she's on read. 😭

type

read-only, ascii 🍓

part name assigned by Dallas Semi. e.g. DS2401. alternative packaging (iButton vs chip) will not be distiguished. ngl, she doesn't care how you're dressed. 🙈

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✨ ALARMS ✨

None. not a single one. we love a calm queen. 😌

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✨ 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-connector scheme where the data line can also provide power. it's giving minimalist icon energy. ⚡

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. 🔐

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. main character = the bus master, fr fr. 👑

bus masters come in a variety of configurations including serial, parallel, i2c, network or USB adapters. so many fits, one girl. 💅

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. yes bestie, the filesystem IS the vibe. 🗂️✨

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. periodt. that's the whole thesis. 🫶

DS2505 DS1985

the DS2505 (3) is used for write-once incremental storage. it's main advantage is for audit trails (i.e. a digital purse). she writes once and she never takes it back. 💅

the DS2505-UNW is one of the UniqueWare class of devices. some of the memory was preprogramed at the factory. see the datasheet for specifics. the DS2502, DS2505, and DS2506 differ in their function by the amount of on-board memory they possess. (the internal protocols are slightly different, but the OWFS system handles this automatically. no notes. 🔥)

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✨ 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. (yes, the original says 12345678ABC right there, we don't count the digits on her, she's iconic. 👑)

the dot is optional, and the CRC code can included. if included, it must be correct. no faking the CRC, bestie, she WILL know. 🚨

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✨ DATASHEET ✨

http://pdfserv.maxim-ic.com/en/ds/DS2505.pdf
http://pdfserv.maxim-ic.com/en/ds/DS2502-UNW-DS2506S-UNW.pdf
http://pdfserv.maxim-ic.com/en/ds/DS1985-F3-DS1985-F5.pdf
http://pdfserv.maxim-ic.com/en/ds/DS1982U-DS1986U.pdf

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✨ 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) InfernoEmbedded (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)

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✨ AVAILABILITY ✨

http://www.owfs.org

go get her, she's online. 🌐

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✨ AUTHOR ✨

Paul Alfille (paul.alfille@gmail.com) — the legend, the blueprint, the moment. 👑

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okay that's the whole page bestie!! this was the OWFS Manpage, version dated 2003, and it's page DS2505(3) of the One-Wire File System docs. mwah. 💋✨🎀