Editing 1-wire


''rough draft''

The 1-wire network is a communications bus system designed by someone(?) at Dallas Semiconductor (now part of Maxim Integrated) that provides low-speed data, signaling, and power, using up a total of one pin on the CPU no matter how many peripheral chips are on that bus.
(Other ways of connecting a peripheral to the CPU either require another pin for each peripheral, or require more pins for the first peripheral, or both).

The 1-wire network is perhaps the most popular way to measure temperatures at many different locations and send that data back to one central processor.


[[Media: A Guide to the 1WRJ45 Standard.pdf]]

It makes it easier to troubleshoot if each PCB
has 2 RJ45 connectors (or a dual RJ45 connector),
with 1 LED indicating power and 1 LED indicating 1-wire signals.

For clarity each of the 8 wires from the standard 1WRJ45 connector
may be labeled with the following 2-letter PCB silkscreen abbreviation:

  1 5R (VCC return)
  2 +5 (VCC power)
  3 AR (Analog return) (?)
  4 OW (one-wire I/O)
  5 OR (one-wire return)
  6 AS (Analog signal) (?)
  7 +V (V raw power)
  8 VR (V raw return)

== Further reading ==


[[Wikipedia: 1-Wire]]

Bich Pham.
"One-Wire Serial Bus Carries Isolated Power And Data".
http://electronicdesign.com/power/one-wire-serial-bus-carries-isolated-power-and-data
The same circuit is also shown in
"APPLICATION NOTE 3754: Single-Wire Serial Bus Carries Isolated Power and Data"
http://www.maximintegrated.com/app-notes/index.mvp/id/3754
uses a MAX845 transformer driver and a transformer
to send power and data from the host to the parasitic-power 1-wire device,
and an optocoupler to send data from the 1-wire device back to the host.

* [http://owfs.org/index.php?page=hubs 1-Wire File System (OWFS): "1-Wire Hubs"] describes several types of 1-wire hubs.

* [http://www.simat.org.uk/ "SIMAT Electronic Projects"] has many links to 1-wire hubs, 1-wire weather station, other 1-Wire Projects, etc.

* The hw-group publishes [http://www.hw-group.com/products/poseidon/pos_interfaces_en.html "Poseidon HW interfaces for sensor connecting"] which has a good description of 1-wire bus on RJ11 connectors and RS-485 bus on RJ45 connectors, as used on their [http://www.hw-group.com/products/sensors/index_en.html "Sensors, Detectors and accessories"].

* The [http://www.midondesign.com/Documents/1-Wire%20Application%20GuideOO103.pdf "midon design: 1-Wire Application Guide"] lists many tips for wiring up a 1-wire bus, including "some popular connector schemes" on 4-wire, 6-wire, and 8-wire connectors.

* The [http://www.shellypark.co.nz/?q=node/2 "Shelly Park Weather Station"] uses a bunch of 1-wire sensors connected to a 1-wire hub. 

* [http://beehivesleuth.com/onewire/pictures.php BeeHiveSleuth: "My 1-Wire Setup"] has detailed photos of a 1-wire network, including temperature sensors inside a bee hive.

* [https://sites.google.com/site/raspberry1wire/ "Using the Hobby Boards 6-channel 1-wire master hub with Raspberry Pi"]


Is it true that
"IEEE 1451.4 uses the Dallas Semiconductor "one-wire" interface"
?
@@ Line 54: / Line 54: @@
 * [https://sites.google.com/site/raspberry1wire/ "Using the Hobby Boards 6-channel 1-wire master hub with Raspberry Pi"]
-* Bernhard Linke. Maxim [http://www.maximintegrated.com/en/app-notes/index.mvp/id/5134 "Application note 5134: Implementing an Isolated 1-Wire Bus"].
-* 1-Wire File System (OWFS): http://owfs.org/
-** has more information on 1-wire bus wiring standards using RJ-11 or RJ45 connectors.[http://owfs.org/index.php?page=wiring-standards]
-* The main page for using Arduino with 1-wire devices: http://playground.arduino.cc/Learning/OneWire
-* read and write 1-wire devices with an 8-bit AVR microcontroller.
-** [http://www.atmel.com/Images/doc2579.pdf Atmel application note  "AVR318: Dallas 1-Wire master"]
-** [https://github.com/z8k/atmel/tree/master/lib/1wire Atmel application note AVR318 source code]
-** [http://www.avrfreaks.net/forum/ds18s20-commumicate-avr "DS18s20 communicate with avr"].
-* [http://protocoltool.sourceforge.net Protocol Tool] supports many protocols, including 1-wire.