DS2409(3)

✨ NAME ✨

DS2409 — the MicroLAN Coupler, bestie. This page lives in the One-Wire File System manual, section 3, and it's literally the glow-up guide for the little chip that lets your 1-wire network have branches. 🌿

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🎀 SYNOPSIS 🎀

It's a 1-wire network branch controller. That's the whole vibe.

1F [.]XXXXXXXXXXXX[XX][/[ aux | branch.[0|1|ALL|BYTE] | control |
discharge | event.[0|1|ALL|BYTE] | clearevent | main |
sensed.[0|1|ALL|BYTE] | address | crc8 | id | locator | r_address | r_id
| r_locator | type ]]

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🌈 FAMILY CODE 🌈

1F

That's it. That's the whole family code. Iconic, honestly.

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💖 SPECIAL PROPERTIES 💖

🦋 aux

• aux — directory. This is the aux branch of the DS2409 network branch. It gets implicitly accessed (through the aux smart-on command, iykyk) whenever you list it, or whenever you address devices sitting on that branch.

🌸 branch.0 branch.1 branch.ALL branch.BYTE

• branch.0, branch.1, branch.ALL, branch.BYTE — read-write, yes-no. Writing a value of 1 to a branch property explicitly selects the branch it's naming (0=main, or 1=aux). Writing 0 deselects that branch. This is a whole addition on top of the directory branch selection scheme you already get by just accessing the main and aux directories. Both ways of picking a branch coexist super nicely, but the latest scheme you use wins. Trying to select both branches at once — either by setting both bits at the same time, or one after the other — fails. And clearing both branch selection bits, again either simultaneously or subsequently, resets the event flags inside the DS2409 as a side effect. Reading the branch properties tells you which branch (if any) is connected to the master bus.

After you use the directory branch selection scheme, both branches get deselected automatically.

ALL is an aggregate of the properties, comma separated, and it's an atomic operation. BYTE is an aggregate of the branches as a byte, with main as bit 0, and it's an atomic operation too.

🎀 control

• control — read-write, unsigned integer. This is the setting of the PIO control pin. There are 4 possible settings, no more, no less:
  1. 0 — Unconditionally off (non-conducting)
  2. 1 — Unconditionally on (conducting)
  3. 2 — Auto on when the main branch is switched in
  4. 3 — Auto on when the aux branch is switched in

💅 discharge

• discharge — write-only, yes-no. Writing a non-zero value here will electrically reset both the main and auxiliary branches of the 1-wire bus by dropping power for 100 milliseconds. Every device on those branches loses its parasitic power and resets to power-up defaults. As a side effect, both event flags — and therefore the alarm state — get cleared too. Dramatic? Yes. Necessary? Also yes.

⭐ event.0 event.1 event.ALL event.BYTE

• event.0, event.1, event.ALL, event.BYTE — read-only, yes-no. Has the event flag for this branch been triggered? A negative edge on the disconnected branch (0=main or 1=aux) sets the flag. You get that by, like, connecting an iButton to the branch. The value returned is 1 (yes) or 0 (no).

After you access the main or aux directory, both branches get deselected automatically, and so the event flags and alarm state get cleared.

ALL is an aggregate of the properties, comma separated, and it's an atomic operation. BYTE is an aggregate of the branches as a byte, with main as bit 0, and it's an atomic operation.

🧚 clearevent

• clearevent — write-only, yes-no. Writing a non-zero value to this property resets both event flags, and therefore clears the alarm state as well.

💜 main

• main — directory. This is the main branch of the DS2409 network branch. It gets implicitly accessed (via the main smart-on command) when it's listed, or when devices on this branch are addressed.

🍓 sensed.0 sensed.1 sensed.ALL sensed.BYTE

• sensed.0, sensed.1, sensed.ALL, sensed.BYTE — read-only, yes-no. Voltage sensed at the 0=main or 1=aux branch pin. This is only valid when the branch is switched out. The value returned is 0 (low) or 1 (high).

ALL is an aggregate of the properties, comma separated, and it's an atomic operation. BYTE is an aggregate of the branches as a byte, with main as bit 0, and it's an atomic operation.

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🔥 STANDARD PROPERTIES 🔥

🌟 address / r_address

• 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 is the address in reverse order, which is often used in other applications and in labeling.

✨ crc8

• crc8 — read-only, ascii. The 8-bit error correction portion. It uses a cyclic redundancy check, computed from the preceding 56 bits of the unique ID number. Given as upper case hexadecimal digits (0-9A-F).

💖 family

• 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

• id, r_id — read-only, ascii. The 48-bit middle portion of the unique ID number. It does not include the family code or the 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 in labeling.

🌸 locator / r_locator

• locator, r_locator — read-only, ascii. This uses an extension of the 1-wire design from the iButtonLink company that associates 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 there's no Link Locator between the device and the master, the locator field will be all FF. r_locator is the locator in reverse order.

💀 present (DEPRECATED)

• present — read-only, yes-no, and also DEPRECATED, so like… it's giving legacy. Is the device currently present on the 1-wire bus?

👑 type

• type — read-only, ascii. Part name assigned by Dallas Semi. E.g. DS2401. Heads up: alternative packaging (iButton vs chip) will not be distinguished.

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🚨 ALARMS 🚨

The DS2409 will respond to a conditional search if the main event flag is set.

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📖 DESCRIPTION 📖

🌐 1-Wire

1-wire is a wiring protocol and a whole 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. Multitasking icon behaviour. 💅

Each device is uniquely and unalterably numbered during manufacture. There's 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.

Bus masters come in a variety of configurations including serial, parallel, i2c, network or USB adapters.

🗂️ OWFS design

OWFS is a suite of programs 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 represented as simple files that can be read and written. So intuitive. So clean.

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.

🌿 DS2409

The DS2409 (3) allows complex 1-wire network topology. Each branch has its power preserved, even when it's isolated from the master. A separate PIO pin can be configured to show branch switching, or controlled explicitly.

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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.

The dot is optional, and the CRC code can be included. If it is included, it must be correct. No pressure or anything. 🫶

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📄 DATASHEET 📄

http://pdfserv.maxim-ic.com/en/ds/DS2409.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

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💌 AUTHOR 💌

Paul Alfille (paul.alfille@gmail.com)

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Okay bestie, that's the whole DS2409 page, every last bit of it. 💖 This was the OWFS Manpage, dated 2003, for DS2409(3) — and yes, section 3, in case you were wondering where to find it in your man setup. Now go forth and branch your MicroLAN. Slay. 👑🦋✨