DS1992(3)

💖 DS1992(3) — One-Wire File System 💖

okay so bestie, sit down, hydrate, because today we're talking about the DS1992: the 1kbit Memory iButton from the One-Wire File System. she's small, she's non-volatile, she remembers everything you tell her (literally, that's her whole thing) and she lives on a 1-wire bus. iconic behavior. let's get into it 💅

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✨ NAME ✨

DS1992 — 1kbit Memory iButton. that's her. that's the girl. 🎀

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✨ SYNOPSIS ✨

Non-volatile memory. (she keeps her memories even when the power goes bye-bye, we love a stable queen 👑)

08 [.]XXXXXXXXXXXX[XX][/[ memory | pages/page.[0-3|ALL] | address | crc8
| id | locator | r_address | r_id | r_locator | type ]]

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✨ FAMILY CODE ✨

• 08 — DS1996

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✨ SPECIAL PROPERTIES ✨

these are the ones that are special to her specifically, the little personality traits 🦋

• memory — read-write, binary. 128 bytes of memory. that's it. that's the storage. 128 lil bytes of pure potential 💾✨
• pages/page.0 ... pages/page.3, pages/page.ALL — read-write, binary. so the memory is split into 4 pages of 32 bytes each. ALL is an aggregate of the pages, like a group chat where everyone's talking at once. each page is accessed sequentially, one after the other, no cutting the line bestie 🙈

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✨ STANDARD PROPERTIES ✨

the classic roster, the ones basically every device has 💖

• address, r_address — read-only, ascii. this is 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. same info, backwards fit, slay 🪞
• 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 checks her own math, no cap 🔍
• family — read-only, ascii. the 8-bit family code. unique to each type of device. given as upper case hexadecimal digits (0-9A-F). it's giving "which family are you from" 🌸
• 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. the middle child, but make it hexadecimal 💜
• 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. she knows where she is at all times, main character energy 🗺️
• present (DEPRECATED) — read-only, yes-no. is the device currently present on the 1-wire bus?

⚠️ heads up bestie: present is DEPRECATED. she's retired, we still love her, but don't build your whole life around her, okay? 💀

• type — read-only, ascii. part name assigned by Dallas Semi. e.g. DS2401. alternative packaging (iButton vs chip) will not be distiguished. (yes, that's the original spelling, we keep the facts exactly as they are, even the typos, no cap 🫶)

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✨ ALARMS ✨

None. absolutely none. she's not an alarm girlie, she's a chill girlie 😌

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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. like, the wire is doing two jobs. multitasking queen 💅

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 range?? unmatched ✨

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. one leader, everyone else gets found by their ID, very "you're all unique and I'll find you" of it 🔥

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

🌸 OWFS design

OWFS is a suite of programs that designed to make the 1-wire bus and its devices easily accessible. (that's the original wording, we don't fix grammar around here, we just vibe 🎀) 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. it's giving "everything is a file" but make it 1-wire 📁💖

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. correctness over speed, periodt ✅

💜 DS1992

the DS1992 (3) is an iButton with static memory. data is read/written with error checking (transparent to the user). the DS1992 (3) , DS1993 (3) , DS1995 (3) , and DS1996 (3) 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.) so like, they're siblings, same energy, different storage capacity. family reunion but they all handled it for you, no stress 🌈

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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 bestie, exactly as written, we do not touch the bits 🫶)

the dot is optional, and the CRC code can included. if included, it must be correct. must. no exceptions, no "close enough", she will not accept your sloppy CRC 💀

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✨ DATASHEET ✨

http://pdfserv.maxim-ic.com/en/ds/DS1992-DS1993.pdf — go read the source material, she's worth it 📖✨

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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 — come through, the whole fam is there 🫶

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✨ AUTHOR ✨

Paul Alfille (paul.alfille@gmail.com) — the actual legend who made all of this happen 👑

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and that's the whole page bestie!! 💖 this was the OWFS Manpage from 2003, filed under DS1992(3). go forth, read your iButton, write your 128 bytes, and remember: she remembers everything, so be nice to her. periodt ✨🎀💅