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en:automation:02-glossary:1wire-hidden [2021/08/05 16:04] – [1-Wire] avsetulaen:automation:02-glossary:1wire-hidden [2025/04/28 16:18] (current) – [Creating a multi-hub extensive network of 1-Wire sensors] updated wrap ofojt
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 1-Wire is a name for a communication bus designed by Dallas Semiconductor company, that is designed for the low-speed transmission of digital signals. As the name suggests 1-Wire sensors can theoretically use only a single conductor for both power voltage and data. The negative pole can be grounded. In practice, however, at least two conductors are used -> 1W (DATA) and GND. 1-Wire sensors from the Unipi product range use four conductors (VCC, {{:files:data_0.png?nolink&15|}}1W, {{:files:data_1.png?nolink&15|}}1W, GND) for better reliability and enhanced serialisation options.  1-Wire is a name for a communication bus designed by Dallas Semiconductor company, that is designed for the low-speed transmission of digital signals. As the name suggests 1-Wire sensors can theoretically use only a single conductor for both power voltage and data. The negative pole can be grounded. In practice, however, at least two conductors are used -> 1W (DATA) and GND. 1-Wire sensors from the Unipi product range use four conductors (VCC, {{:files:data_0.png?nolink&15|}}1W, {{:files:data_1.png?nolink&15|}}1W, GND) for better reliability and enhanced serialisation options. 
  
-A distinct advantage of the 1-Wire bus is the low component price; thermometers available at Unipi e-shop are offered from approx. € 10 apiece. A single bus can be up to 200 m long with up to 15 sensors connected at once. Each sensor is also provided with its own HW address for its addressing on the bus. +A distinct advantage of the 1-Wire bus is the low component price; thermometers available at Unipi e-shop are offered from approx. € 10 apiece. Up to 15 sensors can be connected to the bus, OR a distance of up to 200 m from the controller can be reached (with a lower number of sensors). Each sensor is also provided with its own HW address for its addressing on the bus. 
  
 ===== 1-Wire temperature sensor ===== ===== 1-Wire temperature sensor =====
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 The DS18B20 is widely used 1-Wire temperature sensor placed within TO-92 casing.  The DS18B20 is widely used 1-Wire temperature sensor placed within TO-92 casing. 
  
-  * power voltage range: 3.0V - 5.5V +  * power voltage range: 3.0-5.5 V⎓ 
-  * measurement range: -55°C/+125°C +  * measurement range: -55 °C / +125 °C 
-  * accuracy ±0,5°C in the range of -10°C/+85°C+  * accuracy ±0,5°C in the range of -10 °C / +85 °C
   * conversion of 12-bit temperature value to a digital signal (750 ms max. latency)   * conversion of 12-bit temperature value to a digital signal (750 ms max. latency)
-  * can be powered by the 1W/DATA wire (parasite mode)+  * can be powered by the 1W (DATA) wire - parasite mode
  
 ===== 1-Wire devices offered by Unipi ===== ===== 1-Wire devices offered by Unipi =====
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 {{ :cs:hw:rj45-pinout_1-wire.png?direct&400 |}} {{ :cs:hw:rj45-pinout_1-wire.png?direct&400 |}}
  
-A total of 4 wires is used. However, the connector description above has 6 wires connected, as the VCC (or +5V) and GND voltage conductors can be doubled (depicted by white streaks in the picture). As some devices were not designed for a dual power supply we need to connect the pins 5 and 8 (basic colours) first. +A total of 4 wires is used. However, the connector description above has 6 wires connected, as the VCC (or +5 V⎓) and GND voltage conductors can be doubled (depicted by white streaks in the picture). As some devices were not designed for a dual power supply we need to connect the pins 5 and 8 (basic colours) first. 
  
 ^ Pin (contact) number ^ Meaning ^ ^ Pin (contact) number ^ Meaning ^
 | 1, 2 | unused | | 1, 2 | unused |
 | 3 | GND | | 3 | GND |
-| 4 | VCC (+5V) | +| 4 | VCC (+5 V⎓) | 
-| 5 | VCC (+5V) | +| 5 | VCC (+5 V⎓) | 
-| 6 | {{:files:data_0.png?nolink&15|}}1W (DATA_0) | +| 6 | {{:files:data_0.png?nolink&15|}}1W (DATA_1) | 
-| 7 | {{:files:data_1.png?nolink&15|}}1W (DATA_1) |+| 7 | {{:files:data_1.png?nolink&15|}}1W (DATA_0) |
 | 8 | GND | | 8 | GND |
  
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 <WRAP center round box> <WRAP center round box>
-**Note:** {{:files:data_0.png?nolink&15|}}1W, sometimes also DATA_0, is the main data wire. That said, if you connect a cable sensor with only a single data wire to the RJ45 connector, always connect it to pin 6 (eg. {{:files:data_0.png?nolink&15|}}1W pin). The {{:files:data_1.png?nolink&15|}}1W contact, sometimes also DATA_1, is a supplemental contact of Unipi sensors designed for a maximum possible bus serialization and serves for connecting the next sensor on the bus. The Unipi 1-Wire hub can serve as an example of the double-data wire principle. If you use a non-Unipi cable sensor with only a single data wire, the above-mentioned serialization with Unipi 1-Wire hub is not possible. You can, however, connect the sensor to the end of the bus (eg. as the last sensor in the hub). +**Note:** {{:files:data_1.png?nolink&15|}}1W, sometimes also DATA_0, is the main data wire. That said, if you connect a cable sensor with only a single data wire to the RJ45 connector, always connect it to pin 7 (eg. {{:files:data_1.png?nolink&15|}}1W pin). The {{:files:data_0.png?nolink&15|}}1W contact, sometimes also DATA_1, is a supplemental contact of Unipi sensors designed for a maximum possible bus serialization and serves for connecting the next sensor on the bus. The Unipi 1-Wire hub can serve as an example of the double-data wire principle. If you use a non-Unipi cable sensor with only a single data wire, the above-mentioned serialization with Unipi 1-Wire hub is not possible. You can, however, connect the sensor to the end of the bus (eg. as the last sensor in the hub). 
 </WRAP> </WRAP>
  
- +<WRAP group center round box 95%> 
-<WRAP center round info 90%>+{{ :files:img_warning-line_b.png?nolink |}} 
 +<WRAP half column 13%> 
 +{{ :en:hw:08_safety-instructions_pseudo-ISO-7010-info.png?nolink |(!)}} 
 +</WRAP> 
 +<WRAP half column 83%> 
 +**Note:** \\
 The Unipi [[https://www.unipi.technology/cs/unipi-extension-xg18-p331|Unipi Extension xG18]] module allows an easy connection of multiple temperature sensors using a single data wire, with each sensor having its own channel (connector). Connecting multiple sensors to a single channel is not possible.  The Unipi [[https://www.unipi.technology/cs/unipi-extension-xg18-p331|Unipi Extension xG18]] module allows an easy connection of multiple temperature sensors using a single data wire, with each sensor having its own channel (connector). Connecting multiple sensors to a single channel is not possible. 
 +</WRAP>
 </WRAP> </WRAP>
  
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 All described methods are depicted in the schematics below.  All described methods are depicted in the schematics below. 
  
-<WRAP center round info 90%>+<WRAP group center round box 95%> 
 +{{ :files:img_warning-line_b.png?nolink |}} 
 +<WRAP half column 13%> 
 +{{ :en:hw:08_safety-instructions_pseudo-ISO-7010-info.png?nolink |(!)}} 
 +</WRAP> 
 +<WRAP half column 83%> 
 +**Note:** \\
 The sensor features a 4-wire connection to improve the reliability of branched networks. However, it is possible to modify it for 3-wire connection by joining 1W (DATA) wires if needed. The sensor features a 4-wire connection to improve the reliability of branched networks. However, it is possible to modify it for 3-wire connection by joining 1W (DATA) wires if needed.
  
 You can also short-circuit VCC and GND wires to run the sensor in parasite mode with communication through two wires. You can also short-circuit VCC and GND wires to run the sensor in parasite mode with communication through two wires.
 +</WRAP>
 </WRAP> </WRAP>
    
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 A compact  [[https://www.unipi.technology/1-wire-hub-s-8-porty-p31|8-port 1-Wire hub]] features eight RJ45 ports and allows you to connect multiple 1-Wire thermometers or other sensors with the RJ45 connector. To connect the hub to a controller you can either use a suitable patch cord (on controllers with the RJ45 port) or the [[https://www.unipi.technology/kabelova-1-wire-redukce-rj45-3-pin-svorkovnice-p325|cable reduction]] (on controllers with the newer 3-pin screw terminal).  A compact  [[https://www.unipi.technology/1-wire-hub-s-8-porty-p31|8-port 1-Wire hub]] features eight RJ45 ports and allows you to connect multiple 1-Wire thermometers or other sensors with the RJ45 connector. To connect the hub to a controller you can either use a suitable patch cord (on controllers with the RJ45 port) or the [[https://www.unipi.technology/kabelova-1-wire-redukce-rj45-3-pin-svorkovnice-p325|cable reduction]] (on controllers with the newer 3-pin screw terminal). 
  
-<WRAP center round important 90%>+<WRAP group center round box 95%> 
 +{{ :files:img_warning-line_b.png?nolink |}} 
 +<WRAP half column 13%> 
 +{{ :en:hw:09_safety-instructions_pseudo-ISO-7010-attention.png?nolink |(!)}} 
 +</WRAP> 
 +<WRAP half column 83%> 
 +**Attention:** \\
 It is necessary to follow the correct port order when connecting devices to the hub! Port 1 must be always used as an input port, the remaining ports must not be skipped; otherwise, any devices connected after the skipped port would be cut off from the 1-Wire bus.  It is necessary to follow the correct port order when connecting devices to the hub! Port 1 must be always used as an input port, the remaining ports must not be skipped; otherwise, any devices connected after the skipped port would be cut off from the 1-Wire bus. 
 </WRAP> </WRAP>
 +</WRAP>
 +
 {{:en:hw:hub_simple_eng.png?600|}} {{:en:hw:hub_simple_eng.png?600|}}
  
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 It is possible to create a chain of multiple hubs if an extensive network of 1-Wire sensors or devices is needed. When interconnecting two hubs the topology stays the same - Port 1 serves as an input while the output is located on the last port in order.  It is possible to create a chain of multiple hubs if an extensive network of 1-Wire sensors or devices is needed. When interconnecting two hubs the topology stays the same - Port 1 serves as an input while the output is located on the last port in order. 
  
-<WRAP center round important 90%>+<WRAP group center round box 95%> 
 +{{ :files:img_warning-line_b.png?nolink |}} 
 +<WRAP half column 13%> 
 +{{ :en:hw:09_safety-instructions_pseudo-ISO-7010-attention.png?nolink |(!)}} 
 +</WRAP> 
 +<WRAP half column 83%> 
 +**Attention:** \\
 Any other 1-Wire device connected after the output port will be cut off from the bus!  Any other 1-Wire device connected after the output port will be cut off from the bus! 
- 
 </WRAP> </WRAP>
 +</WRAP>
 +
 {{:en:hw:hubeng.png?600|}} {{:en:hw:hubeng.png?600|}}
  
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 <html><span class="kbBlueText">RJ45 connection</span></html> \\ <html><span class="kbBlueText">RJ45 connection</span></html> \\
 Connection to RJ45-connector network cable is useful for star-shaped network topologies created from 1-Wire hubs. You can also use it to connect the sensor to Unipi 1.1 extension board, or to the older variants of Unipi Neuron controllers.  Connection to RJ45-connector network cable is useful for star-shaped network topologies created from 1-Wire hubs. You can also use it to connect the sensor to Unipi 1.1 extension board, or to the older variants of Unipi Neuron controllers. 
-All these sensors can be also connected to the [[https://www.unipi.technology/unipi-extension-xg18-p331|Unipi Extension xG18 module]]. Coloured connection scheme on the picture corresponds to the T568B connection. +All sensors with the DS18b20 chip and parasite power support can also be connected to the [[https://www.unipi.technology/unipi-extension-xg18-p331|Unipi Extension xG18 module]].. Coloured connection scheme on the picture corresponds to the T568B connection. 
 ;#; ;#;
  
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