DS2770(3)

💖 DS2770 💖

okay bestie, welcome to the DS2770(3) page of the One-Wire File System — yes she's a Battery Monitor and Charge Controller and yes she is lowkey doing the most. grab a snack, this one's long, and we're only on part one 🍓

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✨ NAME ✨

DS2770 — Battery Monitor and Charge Controller 🫶

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🌈 SYNOPSIS 🌈

Temperature Voltage Current Memory and Switch. (the whole girlboss portfolio, fr fr)

2E [.]XXXXXXXXXXXX[XX][/[ amphours | current | currentbias |
lock.[0-2|ALL] | memory | pages/page.[0-2|ALL] | PIO | sensed |
temperature | vbias | vis | volt | volthours |
charge | cini | cstat0 | cstat1 | ctype | defaultpmod | pmod | refresh |
timer |
address | crc8 | id | locator | r_address | r_id | r_locator | type ]]

Thermocouple

2E [.]XXXXXXXXXXXX[XX][/[ temperature | typeX/range_low |
typeX/range_high | typeX/temperature

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👑 FAMILY CODE 👑

2E

that's her family code, that's her whole identity, periodt 💅

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🌸 SPECIAL PROPERTIES 🌸

these are the main-character properties, the ones you'll actually be living in. let's go one by one, no skipping 🔥

• amphours — read-write, floating point. The accumulated amperage that the current sensor picked up on. Units are in Amp-hr (and she assumes the internal 25mOhm resistor, so don't come for her if it's not). Derived from volthours / Rinternal. Formally — and I mean formally — amphours is the integral of current - currentbias over time. math girlie behavior 😭
• current — read-only, floating point. Your current reading. Units are in Amp (again assuming that internal 25 mOhm resistor). Derived from vis / Rinternal.
• currentbias — read-write, floating point. A fixed offset that gets applied to every single current measurement. It's used in the amphours value. Assumes the internal 25mOhm resistor. Units are Amp, and the range is -.08A to .08A. Derived from vbias / Rinternal.
• lock.[0-2|ALL] — read-write, yes-no. Locks either of the three eprom pages so nothing else can be written to them. Apparently setting lock is permanent — so like, vibe check before you commit, bestie, because there is no undo 💀
• memory — read-write, binary. Full access to the entire 256 byte memory range. A lot of that space is reserved or special-use. The user space is the page area. See the DATASHEET for a full memory map.
• pages/pages.[0-2|ALL] — read-write, binary. Two 16 byte areas and one 8 byte area of memory for your user application. The lock property can stop any further alteration. NOTE that the page property is different from the common OWFS implementation, in that not all of memory is accessible. she's special like that 🙈
• PIO — write-only, yes-no. Controls the PIO pin, which lets you switch things externally. Writing "1" turns the PIO pin on (conducting). Writing "0" makes the pin non-conducting. The logical state of the voltage can be read with the sensed property — and heads up, that reflects the current voltage at the pin, not the value you sent to PIO. Also note that PIO will also be altered by the power-status of the DS2670. See the datasheet for details.
• sensed — read-only, yes-no. The logical voltage at the PIO pin. Only actually useful if the PIO property is set to "0" (non-conducting). Value will be 0 or 1 depending on the voltage threshold.
• temperature — read-only, floating point. The temperature the chip read, at high resolution (~13 bits). Units are selected from the invoking command line — see owfs(1) or owhttpd(1) for your choices. Default is Celsius. Conversion is continuous, she never stops ✨
• vbias — read-write, floating point. A fixed offset applied to each vis measurement. Used for the volthours value. Units are in Volts. Range -2.0mV to 2.0mV.
• vis — read-only, floating point. The current sensor reading (with an unknown external resistor). Measures the voltage gradient between the Vis pins. Units are in Volts. The vis readings get integrated over time to give you the volthours property. The current reading is derived from vis assuming the internal 25 mOhm resistor is employed — and ngl, there is no way to know this through software. it's giving mystery 🔍
• volt — read-only, floating point. Voltage read at the voltage sensor. This is separate from the vis voltage that's used for current measurement. Units are Volts. Range is between 0 and 4.75V.
• volthours — read-write, floating point. The integral of vis - vbias over time. Units are in volthours.

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🦋 THERMOCOUPLE 🦋

• typeX/ — directory. A thermocouple circuit using the DS2770 (3) to read the Seebeck voltage and the reference temperature. Since how the values get interpreted depends on the type of thermocouple, you have to choose the correct directory. Supported thermocouple types include types B, E, J, K, N, R, S and T. pick your fighter 💅
• typeX/range_low, typeX/ranges_high — read-only, floating point. The lower and upper temperature supported by this thermocouple (at least by the conversion routines). In the globally chosen temperature units.
• typeX/temperature — read-only, floating point. The thermocouple temperature. Requires a voltage and temperature conversion. Returned in the globally chosen temperature units. Note: there are two types of temperature measurements possible. The temperature value in the main device directory is the reference temperature read at the chip. The typeX/temperature value is at the thermocouple junction, which is probably remote from the chip. two different girls, two different jobs 🎀

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💜 OBSCURE PROPERTIES 💜

these are the deep cuts. iykyk 😌

• charge — write-only, yes-no. Triggers the start (1) or the stop (0) of charging. See the DATASHEET for details.
• cini, cstat0, cstat1, ctype, pmod — varies, yes-no. Bit flags that correspond to the various battery management functions of the chip. See the DATASHEET for details of the identically named entries. In general, writing "0" corresponds to a 0 bit value, and non-zero corresponds to a 1 bit value.
• defaultpmod — read-write, yes-no. Default power-on state for the corresponding properties.
• refresh — write-only, yes-no. Writing anything to this file causes a refresh of parameters. See the
• timer — read-write, floating point. A charge timer, in units of hours. See the DATASHEET for details.

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⭐ STANDARD PROPERTIES ⭐

the classics, the icons, the ones every 1-wire device shows up with 🫶

• 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 labeling.
• 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).
• 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 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 labeling.
• 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.
• present (DEPRECATED) — read-only, yes-no. Is the device currently present on the 1-wire bus? she's deprecated bestie, still here, still iconic, but like... 💀
• type — read-only, ascii. Part name assigned by Dallas Semi. E.g. DS2401. Alternative packaging (iButton vs chip) will not be distinguished.

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🚨 ALARMS 🚨

None.

that's it. nothing. silence. no alarms, no drama 🧚

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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. one wire 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. fancy ✨

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 that's 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. it's giving "everything is a file" and honestly? we're obsessed.

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. she's not in a rush, she's thorough 💅

💖 DS2770 💖

The DS2770 (3) is a battery charging controller. It has elaborate charge estimation algorithms built in. smart girlie behavior.

A number of interesting devices can be built with the DS2770, including thermocouples. Support for thermocouples is built into the software, using the embedded thermister as the cold junction temperature.

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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, but like, it must 🔥

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📄 DATASHEET 📄

http://pdfserv.maxim-ic.com/en/ds/DS2770.pdf

go read it, bestie, she's got the full memory map in there 📚

💖 SEE ALSO 💖

like, bestie, this part is the whole friend group of pages that go with this one. same energy, same family, all of them slay 💅

🌈 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 🌐

the whole entire vibe lives right here, go drink it in:

http://www.owfs.org

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🫶 AUTHOR 🫶

this masterpiece was written by Paul Alfille — yes, THE icon — and you can slide into his inbox at paul.alfille@gmail.com 💌

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okay that's the whole page bestie, we ate and left absolutely no crumbs 💅✨ the page footer says the OWFS Manpage, dated 2003, and it's for DS2770(3) — so yeah, that's the source, the version-year vibe, and the date, all wrapped up with a bow 🎀 no cap, go read the datasheet and stay hydrated 🦋💖