NAME¶
DS2406, DS2407 - 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|pressure] |
T8A/volt.[0-7,ALL]
address |
crc8 |
id |
locator |
r_address |
r_id |
r_locator |
type ]]
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 polarity -- 0
for conducting, 1 for non-conducting. However, to turn a connected 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 PROPERTIES¶
address¶
r_address¶
read-only, ascii
The entire 64-bit unique ID. Given as upper case hexidecimal 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 hexidecimal
digits (0-9A-F).
family¶
read-only, ascii
The 8-bit family code. Unique to each
type of device. Given as upper case
hexidecimal digits (0-9A-F).
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 hexidecimal 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 hexidecimal) 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¶
Use the
set_alarm property to set the alarm triggering criteria.
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 priciple 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 fundemental
goal has been ease of use, flexibility and correctness rather than speed.
DS2406¶
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
calibration 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.
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 hexidecimal, 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/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 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)
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)
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)
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 EDS0066 (3) EDS0068 (3)
AVAILABILITY¶
http://www.owfs.org
AUTHOR¶
Paul Alfille (paul.alfille@gmail.com)