Difference between revisions of "1-wire"
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[[Media: A Guide to the 1WRJ45 Standard.pdf]] | [[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]] | [[Wikipedia: 1-Wire]] | ||
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to send power and data from the host to the parasitic-power 1-wire device, | 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. | 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"] | ||
Revision as of 20:36, 2 November 2014
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
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.
- 1-Wire File System (OWFS): "1-Wire Hubs" describes several types of 1-wire hubs.
- "SIMAT Electronic Projects" has many links to 1-wire hubs, 1-wire weather station, other 1-Wire Projects, etc.
- The hw-group publishes "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 "Sensors, Detectors and accessories".
- The "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 "Shelly Park Weather Station" uses a bunch of 1-wire sensors connected to a 1-wire hub.
- BeeHiveSleuth: "My 1-Wire Setup" has detailed photos of a 1-wire network, including temperature sensors inside a bee hive.
Is it true that
"IEEE 1451.4 uses the Dallas Semiconductor "one-wire" interface"
?
