DS2407(3)

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.

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.