# Two ds18b20 sensors and i get one temperature

**URL:** <https://discourse.nodered.org/t/two-ds18b20-sensors-and-i-get-one-temperature/14979>\
**Category:** General\
**Created:** [31 August 2019 16:55 UTC](https://discourse.nodered.org/t/two-ds18b20-sensors-and-i-get-one-temperature/14979 "2019-08-31T16:55:53Z")\
**Posts on this page:** 20\
**Page:** 1

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**Author:** ![RudiRuessel](https://avatars.discourse-cdn.com/v4/letter/r/919ad9/32.png) [@RudiRuessel](https://discourse.nodered.org/u/RudiRuessel)\
**Post date:** [31 August 2019 16:55 UTC](https://discourse.nodered.org/t/two-ds18b20-sensors-and-i-get-one-temperature/14979/1 "2019-08-31T16:55:53Z")

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My problem is that i have two ds18b20 sensors and in my dashboard the gauge is jumping between this sensors. How my flow has to look like that i get two different temperatures on b  
my dashboard?

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**Author:** ![bakman2](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/bakman2/32/6207_2.png) [@bakman2](https://discourse.nodered.org/u/bakman2)\
**Post date:** [31 August 2019 16:56 UTC](https://discourse.nodered.org/t/two-ds18b20-sensors-and-i-get-one-temperature/14979/2 "2019-08-31T16:56:57Z")

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Add another gauge and connect it to the other sensor ?

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<div class="post-metadata">

**Author:** ![RudiRuessel](https://avatars.discourse-cdn.com/v4/letter/r/919ad9/32.png) [@RudiRuessel](https://discourse.nodered.org/u/RudiRuessel)\
**Post date:** [31 August 2019 16:59 UTC](https://discourse.nodered.org/t/two-ds18b20-sensors-and-i-get-one-temperature/14979/3 "2019-08-31T16:59:34Z")

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i allready tried it but it didnt work

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<div class="post-metadata">

**Author:** ![bakman2](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/bakman2/32/6207_2.png) [@bakman2](https://discourse.nodered.org/u/bakman2)\
**Post date:** [31 August 2019 17:00 UTC](https://discourse.nodered.org/t/two-ds18b20-sensors-and-i-get-one-temperature/14979/4 "2019-08-31T17:00:11Z")

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What doesn't work ?  
What does your flow look like ? What data do you receive ?

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<div class="post-metadata">

**Author:** ![ukmoose](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/ukmoose/32/13_2.png) [@ukmoose](https://discourse.nodered.org/u/ukmoose)\
**Post date:** [31 August 2019 17:09 UTC](https://discourse.nodered.org/t/two-ds18b20-sensors-and-i-get-one-temperature/14979/5 "2019-08-31T17:09:52Z")

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Does this mean your other problem is now fixed?

There’s no point adding another sensor until you’ve fixed the other issue.

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**Author:** ![zenofmud](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/zenofmud/32/316_2.png) [@zenofmud](https://discourse.nodered.org/u/zenofmud)\
**Post date:** [31 August 2019 17:26 UTC](https://discourse.nodered.org/t/two-ds18b20-sensors-and-i-get-one-temperature/14979/6 "2019-08-31T17:26:31Z")

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What node are you using to read the ds18b20s? There is at least one that you can specify the serial number of the sensor so you could have two of that node to read each sensor separately and send the results to two different gauges.

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<div class="post-metadata">

**Author:** ![RudiRuessel](https://avatars.discourse-cdn.com/v4/letter/r/919ad9/32.png) [@RudiRuessel](https://discourse.nodered.org/u/RudiRuessel)\
**Post date:** [31 August 2019 17:39 UTC](https://discourse.nodered.org/t/two-ds18b20-sensors-and-i-get-one-temperature/14979/7 "2019-08-31T17:39:56Z")

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i think the name of the node is rpi-ds18b20

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<div class="post-metadata">

**Author:** ![zenofmud](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/zenofmud/32/316_2.png) [@zenofmud](https://discourse.nodered.org/u/zenofmud)\
**Post date:** [31 August 2019 18:14 UTC](https://discourse.nodered.org/t/two-ds18b20-sensors-and-i-get-one-temperature/14979/8 "2019-08-31T18:14:24Z")

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Nope, that is not the full name of a node-red node. It will be something like `node-red-contrib-....`

You can go to the hamburger menu and select `Manage Palette` and see all the installed nodes.

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<div class="post-metadata">

**Author:** ![JayDickson](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/jaydickson/32/90592_2.png) [@JayDickson](https://discourse.nodered.org/u/JayDickson)\
**Post date:** [31 August 2019 18:50 UTC](https://discourse.nodered.org/t/two-ds18b20-sensors-and-i-get-one-temperature/14979/9 "2019-08-31T18:50:54Z")

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Can we get the output of your sensor messages? sounds like you're not distinguising between separate unique IDs. Are they wired independently or in series?

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<div class="post-metadata">

**Author:** ![RudiRuessel](https://avatars.discourse-cdn.com/v4/letter/r/919ad9/32.png) [@RudiRuessel](https://discourse.nodered.org/u/RudiRuessel)\
**Post date:** [31 August 2019 19:22 UTC](https://discourse.nodered.org/t/two-ds18b20-sensors-and-i-get-one-temperature/14979/10 "2019-08-31T19:22:45Z")

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they are in series

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<div class="post-metadata">

**Author:** ![JayDickson](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/jaydickson/32/90592_2.png) [@JayDickson](https://discourse.nodered.org/u/JayDickson)\
**Post date:** [31 August 2019 19:25 UTC](https://discourse.nodered.org/t/two-ds18b20-sensors-and-i-get-one-temperature/14979/11 "2019-08-31T19:25:40Z")

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The 1wire protocol those use should include a unique ID for each message to filter by. Can we get the output of a debug node set to display the entire message object? (enough output to get both sensors would be preferred.)

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<div class="post-metadata">

**Author:** ![RudiRuessel](https://avatars.discourse-cdn.com/v4/letter/r/919ad9/32.png) [@RudiRuessel](https://discourse.nodered.org/u/RudiRuessel)\
**Post date:** [31 August 2019 19:29 UTC](https://discourse.nodered.org/t/two-ds18b20-sensors-and-i-get-one-temperature/14979/12 "2019-08-31T19:29:38Z")

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sorry i dont get it

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<div class="post-metadata">

**Author:** ![bakman2](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/bakman2/32/6207_2.png) [@bakman2](https://discourse.nodered.org/u/bakman2)\
**Post date:** [31 August 2019 19:51 UTC](https://discourse.nodered.org/t/two-ds18b20-sensors-and-i-get-one-temperature/14979/13 "2019-08-31T19:51:52Z")

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Post the debug output of the node that produces the payload.

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<div class="post-metadata">

**Author:** ![RudiRuessel](https://avatars.discourse-cdn.com/v4/letter/r/919ad9/32.png) [@RudiRuessel](https://discourse.nodered.org/u/RudiRuessel)\
**Post date:** [1 September 2019 21:13 UTC](https://discourse.nodered.org/t/two-ds18b20-sensors-and-i-get-one-temperature/14979/14 "2019-09-01T21:13:02Z")

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1.9.2019, 23:11:05[node: 68190ba5.39b314](http://127.0.0.1:1880/#)8A1579970203 : msg.payload : number

22.187

1.9.2019, 23:11:06[node: 68190ba5.39b314](http://127.0.0.1:1880/#)AAF8E0521401 : msg.payload : number

23.562

1.9.2019, 23:11:10[node: 68190ba5.39b314](http://127.0.0.1:1880/#)8A1579970203 : msg.payload : number

22.187

1.9.2019, 23:11:11[node: 68190ba5.39b314](http://127.0.0.1:1880/#)AAF8E0521401 : msg.payload : number

23.562

1.9.2019, 23:11:15[node: 68190ba5.39b314](http://127.0.0.1:1880/#)8A1579970203 : msg.payload : number

22.187

1.9.2019, 23:11:16[node: 68190ba5.39b314](http://127.0.0.1:1880/#)AAF8E0521401 : msg.payload : number

23.562

1.9.2019, 23:11:20[node: 68190ba5.39b314](http://127.0.0.1:1880/#)8A1579970203 : msg.payload : number

22.125

1.9.2019, 23:11:21[node: 68190ba5.39b314](http://127.0.0.1:1880/#)AAF8E0521401 : msg.payload : number

23.562

1.9.2019, 23:11:25[node: 68190ba5.39b314](http://127.0.0.1:1880/#)8A1579970203 : msg.payload : number

22.125

1.9.2019, 23:11:26[node: 68190ba5.39b314](http://127.0.0.1:1880/#)AAF8E0521401 : msg.payload : number

23.562

1.9.2019, 23:11:30[node: 68190ba5.39b314](http://127.0.0.1:1880/#)8A1579970203 : msg.payload : number

22.125

1.9.2019, 23:11:31[node: 68190ba5.39b314](http://127.0.0.1:1880/#)AAF8E0521401 : msg.payload : number

23.5

1.9.2019, 23:11:35[node: 68190ba5.39b314](http://127.0.0.1:1880/#)8A1579970203 : msg.payload : number

22.125

1.9.2019, 23:11:36[node: 68190ba5.39b314](http://127.0.0.1:1880/#)AAF8E0521401 : msg.payload : number

23.5

1.9.2019, 23:11:40[node: 68190ba5.39b314](http://127.0.0.1:1880/#)8A1579970203 : msg.payload : number

22.062

1.9.2019, 23:11:41[node: 68190ba5.39b314](http://127.0.0.1:1880/#)AAF8E0521401 : msg.payload : number

23.5

1.9.2019, 23:11:45[node: 68190ba5.39b314](http://127.0.0.1:1880/#)8A1579970203 : msg.payload : number

22.125

1.9.2019, 23:11:46[node: 68190ba5.39b314](http://127.0.0.1:1880/#)AAF8E0521401 : msg.payload : number

23.5

1.9.2019, 23:11:50[node: 68190ba5.39b314](http://127.0.0.1:1880/#)8A1579970203 : msg.payload : number

22.062

1.9.2019, 23:11:51[node: 68190ba5.39b314](http://127.0.0.1:1880/#)AAF8E0521401 : msg.payload : number

23.5

1.9.2019, 23:11:55[node: 68190ba5.39b314](http://127.0.0.1:1880/#)8A1579970203 : msg.payload : number

22.062

1.9.2019, 23:11:56[node: 68190ba5.39b314](http://127.0.0.1:1880/#)AAF8E0521401 : msg.payload : number

23.5

1.9.2019, 23:12:00[node: 68190ba5.39b314](http://127.0.0.1:1880/#)8A1579970203 : msg.payload : number

22.062

1.9.2019, 23:12:01[node: 68190ba5.39b314](http://127.0.0.1:1880/#)AAF8E0521401 : msg.payload : number

23.5

1.9.2019, 23:12:05[node: 68190ba5.39b314](http://127.0.0.1:1880/#)8A1579970203 : msg.payload : number

22.062

1.9.2019, 23:12:06[node: 68190ba5.39b314](http://127.0.0.1:1880/#)AAF8E0521401 : msg.payload : number

23.5

1.9.2019, 23:12:10[node: 68190ba5.39b314](http://127.0.0.1:1880/#)8A1579970203 : msg.payload : number

22

1.9.2019, 23:12:11[node: 68190ba5.39b314](http://127.0.0.1:1880/#)AAF8E0521401 : msg.payload : number

23.437

1.9.2019, 23:12:16[node: 68190ba5.39b314](http://127.0.0.1:1880/#)8A1579970203 : msg.payload : number

22.062

1.9.2019, 23:12:17[node: 68190ba5.39b314](http://127.0.0.1:1880/#)AAF8E0521401 : msg.payload : number

23.437

1.9.2019, 23:12:20[node: 68190ba5.39b314](http://127.0.0.1:1880/#)8A1579970203 : msg.payload : number

22.062

1.9.2019, 23:12:20[node: 68190ba5.39b314](http://127.0.0.1:1880/#)AAF8E0521401 : msg.payload : number

23.437

1.9.2019, 23:12:27[node: 68190ba5.39b314](http://127.0.0.1:1880/#)8A1579970203 : msg.payload : number

22

1.9.2019, 23:12:27[node: 68190ba5.39b314](http://127.0.0.1:1880/#)AAF8E0521401 : msg.payload : number

23.437

1.9.2019, 23:12:30[node: 68190ba5.39b314](http://127.0.0.1:1880/#)8A1579970203 : msg.payload : number

22

1.9.2019, 23:12:30[node: 68190ba5.39b314](http://127.0.0.1:1880/#)AAF8E0521401 : msg.payload : number

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<div class="post-metadata">

**Author:** ![RudiRuessel](https://avatars.discourse-cdn.com/v4/letter/r/919ad9/32.png) [@RudiRuessel](https://discourse.nodered.org/u/RudiRuessel)\
**Post date:** [1 September 2019 21:14 UTC](https://discourse.nodered.org/t/two-ds18b20-sensors-and-i-get-one-temperature/14979/15 "2019-09-01T21:14:50Z")

</div>

This is the output. I see that there are two sensors which deliver different temperatures, but i dont know how to get two different gauges from that.

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<div class="post-metadata">

**Author:** ![ukmoose](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/ukmoose/32/13_2.png) [@ukmoose](https://discourse.nodered.org/u/ukmoose)\
**Post date:** [1 September 2019 21:18 UTC](https://discourse.nodered.org/t/two-ds18b20-sensors-and-i-get-one-temperature/14979/16 "2019-09-01T21:18:27Z")

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What do you see if you change the debug to display the complete msg object rather than just msg.payload?

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<div class="post-metadata">

**Author:** ![RudiRuessel](https://avatars.discourse-cdn.com/v4/letter/r/919ad9/32.png) [@RudiRuessel](https://discourse.nodered.org/u/RudiRuessel)\
**Post date:** [1 September 2019 21:20 UTC](https://discourse.nodered.org/t/two-ds18b20-sensors-and-i-get-one-temperature/14979/17 "2019-09-01T21:20:18Z")

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{ topic: "8A1579970203", payload: 21.75, \_msgid: "4c041b5d.7be074", file: "28-03029779158a", dir: "w1\_bus\_master1" … }

1.9.2019, 23:19:48[node: 68190ba5.39b314](http://127.0.0.1:1880/#)AAF8E0521401 : msg : Object

{ topic: "AAF8E0521401", payload: 23.187, \_msgid: "4c041b5d.7be074", file: "28-011452e0f8aa", dir: "w1\_bus\_master1" … }

1.9.2019, 23:19:53[node: 68190ba5.39b314](http://127.0.0.1:1880/#)8A1579970203 : msg : Object

{ topic: "8A1579970203", payload: 21.312, \_msgid: "3b381108.2a1a6e", file: "28-03029779158a", dir: "w1\_bus\_master1" … }

1.9.2019, 23:19:53[node: 68190ba5.39b314](http://127.0.0.1:1880/#)AAF8E0521401 : msg : Object

{ topic: "AAF8E0521401", payload: 23.187, \_msgid: "3b381108.2a1a6e", file: "28-011452e0f8aa", dir: "w1\_bus\_master1" … }

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<div class="post-metadata">

**Author:** ![RudiRuessel](https://avatars.discourse-cdn.com/v4/letter/r/919ad9/32.png) [@RudiRuessel](https://discourse.nodered.org/u/RudiRuessel)\
**Post date:** [1 September 2019 21:22 UTC](https://discourse.nodered.org/t/two-ds18b20-sensors-and-i-get-one-temperature/14979/18 "2019-09-01T21:22:25Z")

</div>

In the chart there are two different temperatures of the two sensors shown.

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<div class="post-metadata">

**Author:** ![ukmoose](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/ukmoose/32/13_2.png) [@ukmoose](https://discourse.nodered.org/u/ukmoose)\
**Post date:** [1 September 2019 21:24 UTC](https://discourse.nodered.org/t/two-ds18b20-sensors-and-i-get-one-temperature/14979/19 "2019-09-01T21:24:34Z")

</div>

So if you look at your debug you can see the two sensors with different topic. So you can use a switch node to send them to different outputs

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<div class="post-metadata">

**Author:** ![RudiRuessel](https://avatars.discourse-cdn.com/v4/letter/r/919ad9/32.png) [@RudiRuessel](https://discourse.nodered.org/u/RudiRuessel)\
**Post date:** [1 September 2019 21:36 UTC](https://discourse.nodered.org/t/two-ds18b20-sensors-and-i-get-one-temperature/14979/20 "2019-09-01T21:36:42Z")

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Ok, thanks for that. I insert the switch node, but there is no Temperature shown but only "true". I think I must somehow tell the switch which sensor should be connected whith which gauge. Am I right?

[Next page](https://discourse.nodered.org/t/two-ds18b20-sensors-and-i-get-one-temperature/14979.md?page=2)