DS2406(3) One-Wire File System DS2406(3)NAME
DS2406, DS2407 - Dual Addressable Switch with 1kbit Memory, Hidable
Dual Addressable Switch with 1kbit Memory
SYNOPSIS
Dual Switch, Write-once Memory
12 [.]XXXXXXXXXXXX[XX][/[ channels | latch.[A|B|ALL|BYTE] | memory |
pages/page.[0-3|ALL] | PIO.[A|B|ALL|BYTE] | power |
sensed.[A|B|ALL|BYTE] | set_alarm | TAI8570/[sibling|temperature|pres‐
sure] | T8A/volt.[0-7,ALL] ]]
FAMILY CODE
12
SPECIAL PROPERTIES
channels
read-only, unsigned integer
Is this a 1 or 2 channel switch? The DS2406 comes in two forms, one has
only one PIO pin (PIO.A). Returns 1 or 2.
latch.A latch.B latch.ALL latch.BYTE
read-write, yes-no
The activity latch is set to 1 with the first negative or positive edge
detected on the associated PIO channel.
Writing any data will clear latch for all (both)) channels. This is a
hardware "feature" of the chip.
ALL references both channels simultaneously, comma separated
BYTE references both channels simultaneously as a single byte, with
channel A in bit 0.
memory
read-write, binary
128 bytes of non-volatile, write-once data.
pages/page.0 ... pages/page.3 pages/page.ALL
read-write, binary
Memory organized as 4 pages or 32 bytes. Memory is write-once.
ALL is the aggregate of all 4 pages, sequentially accessed.
PIO.A PIO.B PIO.ALL PIO.BYTE
read-write, yes-no
State of the open-drain output ( PIO ) pin. 0 = non-conducting (off), 1
= conducting (on).
Writing zero will turn off the switch, non-zero will turn on the
switch. Reading the PIO state will return the switch setting (flipflop
in the data sheet). To determine the actual logic level at the switch,
refer to the sensed property.
Note that the actual pin setting for the chip uses the opposite polar‐
ity -- 0 for conducting, 1 for non-conducting. However, to turn a con‐
nected device on (i.e. to deliver power) we use the software concept of
1 as conducting or "on".
ALL references both channels simultaneously, comma separated.
BYTE references both channels simultaneously as a single byte, with
channel A in bit 0.
power
read-only, yes-no
Is the DS2406 powered parasitically =0 or separately on the Vcc pin =1
sensed.A sensed.B sensed.ALL sensed.BYTE
read-only, yes-no
Logic level at the PIO pin. 0 = ground. 1 = high (~2.4V - 5V ). Really
makes sense only if the PIO state is set to zero (off), else will read
zero.
ALL references both channels simultaneously, comma separated.
BYTE references both channels simultaneously as a single byte, with
channel A in bit 0.
set_alarm
read-write, unsigned integer (0-331)
A number consisting of three digits XYZ, where:
X channel selection
0 neither
1 A only
2 B only
3 A or B
Y source selection
0 undefined
1 latch
2 PIO
3 sensed
Z polarity selection
0 low
1 high
All digits will be truncated to the 0-3 (or 0-1) range. Leading zeroes
are optional (and may be problematic for some shells).
Example:
311 Responds on Conditional Search when either latch.A or latch.B
(or both) are set to 1.
<100 Never responds to Conditional Search.
TAI8570/
subdirectory
Properties when the DS2406 (3) is built into a TAI8570.
If the DS2406 (3) is not part of a TAI8570 or is not the controlling
switch, attempts to read will result in an error.
TAI8570/pressure
read-only, floating point
Barometric pressure in millibar.
TAI8570/sibling
read-only, ascii
Hex address of the DS2406 (3) paired with this chip in a TAI8570.
TAI8570/temperature
read-only, floating-point
Ambient temperature measured by the TAI8570 in prevailing temperature
units (Centigrade is the default).
T8A/volt.[0-7|ALL]
read-only, floating-point
Uses the T8A (by Embedded Data Systems ) 8 channel voltage converter.
Units in volts, 0 to 5V range. 12 bit resolution.
STANDARD PROPERTIESALARMS
Use the set_alarm property to set the alarm triggering criteria.
DESCRIPTIONDS2406
The DS2406 (3) allows control of other devices, like LEDs and relays.
It superceeds the DS2405 and DS2407 Alternative switches include the
DS2408 or even DS2450
The DS2407 is practically identical to the DS2406 except for a strange
hidden mode. It is supported just like the DS2406
TAI8570
The TAI-8570 Pressure Sensor is based on a 1-wire composite device by
AAG Electronica. The TAI8570 uses 2 DS2406 (3) chips, paired as a
reader and writer to synthesize 3-wire communication. Only 1 of the
DS2406 (3) will allow temperature or pressure readings. It's mate's
address can be shown as sibling.
The TAI8570 uses the Intersema MS5534a pressure sensor, and stores cal‐
ibration and temperature compensation values internally.
Design and code examples are available from AAG Electronica
http://aag.com.mx , specific permission to use code in a GPL product
was given by Mr. Aitor Arrieta of AAG and Dr. Simon Melhuish of OWW.
ADDRESSINGDATASHEET
http://pdfserv.maxim-ic.com/en/ds/DS2406.pdf
http://pdfserv.maxim-ic.com/en/ds/DS2407.pdf
http://www.embeddeddatasystems.com/page/EDS/PROD/IO/T8A
http://oww.sourceforge.net/hardware.html#bp
SEE ALSOAVAILABILITY
http://www.owfs.org
AUTHOR
Paul Alfille (paul.alfille@gmail.com)
OWFS Manpage 2003 DS2406(3)
