DS28EA00(3) One-Wire File System DS28EA00(3)

# [NAME](#NAME)

**DS28EA00** - 1-Wire Digital Thermometer with Sequence Detect and PIO

# [SYNOPSIS](#SYNOPSIS)

Thermometer, PIO and Chain.

**42** \[.]XXXXXXXXXXXX\[XX][/[

See the file man3/temperatures\_mini.3so.

| **latesttemp** | **die** | **power** | **temphigh** | **templow** | **tempres** | **PIO.A|B|ALL.BYTE** | **latch.A|B|ALL.BYTE** | **sensed.A|B|ALL.BYTE**

See the file man3/standard\_mini.3so.

]]

# [FAMILY CODE](#FAMILY_CODE)

*42*

# SPECIAL PROPERTIES

## [power](#power)

*read-only,yes-no*  
Is the chip powered externally (=1) or from the parasitically from the data bus (=0)?

# [TEMPERATURE PROPERTIES](#TEMPERATURE_PROPERTIES)

## [temperature](#temperature)

*read-only, floating point*  
Measured temperature with 12 bit resolution.

## [temperature9 temperature10 temperature11 temperature12](#temperature9_temperature10_temperature11_temperature12)

*read-only, floating point*  
Measured temperature at 9 to 12 bit resolution. There is a tradeoff of time versus accuracy in the temperature measurement.

## [latesttemp](#latesttemp)

*read-only, floating point*  
Measured temperature at 9 to 12 bit resolution, depending on the resolution of the latest conversion on this chip. Reading this node will never trigger a temperature conversion. Intended for use in conjunction with **/simultaneous/temperature.**

## [fasttemp](#fasttemp)

*read-only, floating point*  
Equivalent to *temperature9*

# [PIO PROPERTIES](#PIO_PROPERTIES)

## [PIO.A|B|ALL|BYTE](#PIO.A_B_ALL_BYTE)

*read-write, yes-no*  
Two channels of sensors/switches. We use the logical raqther than eletrical interpretation: 0=off (non-conducting) 1=on (conducting -- to ground)

The *PIO* channels are alternatively used for the sequence-detect (chain) mode.

Reading *sensed* gives the inverse value of the cooresponding *PIO.*

Reading *PIO* gives the actual pin values. Use the *latch* property to see how the pin is set.

## [latch.A|B|ALL|BYTE](#latch.A_B_ALL_BYTE)

*read-only, yes-no*  
Set (intended) va;ue of the *PIO* pins.

## [sensed.A|B|ALL|BYTE](#sensed.A_B_ALL_BYTE)

*read-only, yes-no*  
Actual logical level at the *PIO* pins.

# SPECIAL PROPERTIES

## [power](#power~2)

*read-only,yes-no*  
Is the chip powered externally (=1) or from the parasitically from the data bus (=0)?

See the file man3/temperature\_threshold.3so.

See the file man3/temperature\_resolution.3so.

# [STANDARD PROPERTIES](#STANDARD_PROPERTIES)

See the file man3/standard.3so.

# [DESCRIPTION](#DESCRIPTION)

See the file man3/description.3so.

## [DS28EA00](#DS28EA00)

The [**DS28EA00 (3)**](/man/os/owfs/DS28EA00.3) is one of several available 1-wire temperature sensors. It is the replacement for the [**DS18S20 (3)**](/man/os/owfs/DS18S20.3) Alternatives are [**DS1822 (3)**](/man/os/owfs/DS1822.3) as well as temperature/vlotage measurements in the [**DS2436 (3)**](/man/os/owfs/DS2436.3) and **[DS2438 (3)](/man/os/owfs/DS2438.3).** For truly versatile temperature measurements, see the protean **[DS1921 (3)](/man/os/owfs/DS1921.3) [Thermachron (3)](/man/os/owfs/Thermachron.3).**  
The **DS28EA00** has special switch/sequence detect properties. In sequence mode, the PIO pins are daisy-chained to the next DS28EA00, allowing the system to step through the physical sequence of the DS28EA00s.

# [ADDRESSING](#ADDRESSING)

See the file man3/addressing.3so.

# [DATASHEET](#DATASHEET)

http://pdfserv.maxim-ic.com/en/ds/DS28EA00.pdf

# [SEE ALSO](#SEE_ALSO)

See the file man3/seealso.3so.

# [AVAILABILITY](#AVAILABILITY)

http://www.owfs.org

# [AUTHOR](#AUTHOR)

Paul Alfille (paul.alfille@gmail.com)

2003 OWFS Manpage

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Document: DS28EA00(3) from owfs 3.2.4-r10 (Chainguard OS)
Source: https://github.com/owfs/owfs