--- name: "DS2770" section: "3" platform: "linux" package: "owfs-doc" version: "3.2p4+dfsg1-6" release: "Debian 13 (Trixie)" platforms: ["linux"] url: "https://new.carta.tech/DS2770" --- # DS2770(3) Battery Monitor and Charge Controller ## NAME **DS2770** - Battery Monitor and Charge Controller ## SYNOPSIS ### Temperature Voltage Current Memory and Switch. **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** ## FAMILY CODE *2E* ## SPECIAL PROPERTIES ### amphours *read-write, floating point*\ Accumulated amperage read by current sensor. Units are in **Amp-hr** (Assumes internal 25mOhm resistor). Derived from *volthours* / Rinternal.\ Formally *amphours* is the integral of *current - currentbias* over time. ### current *read-only, floating point*\ Current reading. Units are in **Amp** (Assumes internal 25 mOhm resistor). Derived from *vis* / Rinternal. ### currentbias *read-write, floating point*\ Fixed offset applied to each *current* measurement. Used in the *amphours* value. Assumes internal 25mOhm resistor. Units are **Amp** and range from -.08A to .08A.\ Derived from *vbias* / Rinternal. ### lock.\[0-2\|ALL\] *read-write, yes-no*\ Lock either of the three eprom pages to prevent further writes. Apparently setting *lock* is permanent. ### memory *read-write, binary*\ Access to the full 256 byte memory range. Much of this space is reserved or special use. 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 and one 8 byte areas of memory for user application. The *lock* property can prevent further alteration.\ NOTE that the *page* property is different from the common *OWFS* implementation in that all of *memory* is not accessible. ### PIO *write-only, yes-no*\ Controls the PIO pin allowing external switching.\ 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. This will reflect the current voltage at the pin, not the value sent to *PIO*\ Note also 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. Useful only 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*\ *Temperature* read by the chip at high resolution (~13 bits). Units are selected from the invoking command line. See **[owfs(1)](/owfs/1.md)** or **[owhttpd(1)](/owhttpd/1.md)** for choices. Default is Celsius.\ Conversion is continuous. ### vbias *read-write, floating point*\ 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*\ Current sensor reading (unknown external resistor). Measures the voltage gradient between the Vis pins. Units are in **Volts**\ The *vis* readings are integrated over time to provide the *volthours* property.\ The *current* reading is derived from *vis* assuming the internal 25 mOhm resistor is employed. There is no way to know this through software. ### volt *read-only, floating point*\ Voltage read at the voltage sensor;. This is separate from the *vis* voltage that is used for *current* measurement. Units are **Volts**\ Range is between 0 and 4.75V ### volthours *read-write, floating point*\ Integral of *vis - vbias* over time. Units are in **volthours** ## THERMOCOUPLE ### typeX/ *directory*\ Thermocouple circuit using the **DS2770 (3)** to read the Seebeck voltage and the reference temperature. Since the type interpretation of the values read depends on the type of thermocouple, the correct directory must be chosen. Supported thermocouple types include types B, E, J, K, N, R, S and T. ### typeX/range\_low typeX/ranges\_high *read-only, flaoting 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*\ Thermocouple temperature. Requires a voltage and temperature conversion. Returned in 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, probably remote from the chip. ## OBSCURE PROPERTIES ### charge *write-only, yes-no*\ Trigger the start (1) or stop(0) of charging. see the *DATASHEET* for details. ### cini cstat0 cstat1 ctype pmod *varies, yes-no*\ Bit flags corresponding to 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. ## 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* 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 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? ### type *read-only, ascii*\ Part name assigned by Dallas Semi. E.g. *DS2401* Alternative packaging (iButton vs chip) will not be distiguished. ## ALARMS None. ## 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. 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. 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 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. 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. ### DS2770 The **DS2770 (3)** is a battery charging controller. It has elaborate charge estimation algorithms built in. A number of interesting devices can be built with the **DS2770** including thermocouples. Support for thermocouples in built into the software, using the embedded thermister as the cold junction temperature. ## 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 included. If included, it must be correct. ## DATASHEET http://pdfserv.maxim-ic.com/en/ds/DS2770.pdf ## 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)** ## AVAILABILITY http://www.owfs.org ## AUTHOR Paul Alfille (paul.alfille@gmail.com)