DS28EA00(3)

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

SYNOPSIS
Thermometer, PIO and Chain.

42 [.]XXXXXXXXXXXX[XX][/[ | latesttemp | die | power | temphigh | templow | tempres | PIO.A|B|ALL.BYTE | latch.A|B|ALL.BYTE | sensed.A|B|ALL.BYTE ]]

FAMILY CODE

42

SPECIAL PROPERTIES

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

TEMPERATURE PROPERTIES

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

  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
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
read-only, floating point
Equivalent to temperature9

PIO PROPERTIES

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

  sensed.A|B|ALL|BYTE
read-only, yes-no
Actual logical level at the PIO pins.

SPECIAL PROPERTIES

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

STANDARD PROPERTIES

DESCRIPTION

  DS28EA00
The DS28EA00 (3) is one of several available 1-wire temperature sensors. It is the replacement for the DS18S20 (3) Alternatives are DS1822 (3) as well as temperature/vlotage measurements in the DS2436 (3) and DS2438 (3). For truly versatile temperature measurements, see the protean DS1921 (3) 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

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

SEE ALSO

AVAILABILITY
http://www.owfs.org

AUTHOR
Paul Alfille (paul.alfille@gmail.com)