Two ds18b20 sensors and i get one temperature

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?

Add another gauge and connect it to the other sensor ?

i allready tried it but it didnt work

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

Does this mean your other problem is now fixed?

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

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.

i think the name of the node is rpi-ds18b20

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.

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?

they are in series

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.)

sorry i dont get it

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

1.9.2019, 23:11:05node: 68190ba5.39b3148A1579970203 : msg.payload : number

22.187

1.9.2019, 23:11:06node: 68190ba5.39b314AAF8E0521401 : msg.payload : number

23.562

1.9.2019, 23:11:10node: 68190ba5.39b3148A1579970203 : msg.payload : number

22.187

1.9.2019, 23:11:11node: 68190ba5.39b314AAF8E0521401 : msg.payload : number

23.562

1.9.2019, 23:11:15node: 68190ba5.39b3148A1579970203 : msg.payload : number

22.187

1.9.2019, 23:11:16node: 68190ba5.39b314AAF8E0521401 : msg.payload : number

23.562

1.9.2019, 23:11:20node: 68190ba5.39b3148A1579970203 : msg.payload : number

22.125

1.9.2019, 23:11:21node: 68190ba5.39b314AAF8E0521401 : msg.payload : number

23.562

1.9.2019, 23:11:25node: 68190ba5.39b3148A1579970203 : msg.payload : number

22.125

1.9.2019, 23:11:26node: 68190ba5.39b314AAF8E0521401 : msg.payload : number

23.562

1.9.2019, 23:11:30node: 68190ba5.39b3148A1579970203 : msg.payload : number

22.125

1.9.2019, 23:11:31node: 68190ba5.39b314AAF8E0521401 : msg.payload : number

23.5

1.9.2019, 23:11:35node: 68190ba5.39b3148A1579970203 : msg.payload : number

22.125

1.9.2019, 23:11:36node: 68190ba5.39b314AAF8E0521401 : msg.payload : number

23.5

1.9.2019, 23:11:40node: 68190ba5.39b3148A1579970203 : msg.payload : number

22.062

1.9.2019, 23:11:41node: 68190ba5.39b314AAF8E0521401 : msg.payload : number

23.5

1.9.2019, 23:11:45node: 68190ba5.39b3148A1579970203 : msg.payload : number

22.125

1.9.2019, 23:11:46node: 68190ba5.39b314AAF8E0521401 : msg.payload : number

23.5

1.9.2019, 23:11:50node: 68190ba5.39b3148A1579970203 : msg.payload : number

22.062

1.9.2019, 23:11:51node: 68190ba5.39b314AAF8E0521401 : msg.payload : number

23.5

1.9.2019, 23:11:55node: 68190ba5.39b3148A1579970203 : msg.payload : number

22.062

1.9.2019, 23:11:56node: 68190ba5.39b314AAF8E0521401 : msg.payload : number

23.5

1.9.2019, 23:12:00node: 68190ba5.39b3148A1579970203 : msg.payload : number

22.062

1.9.2019, 23:12:01node: 68190ba5.39b314AAF8E0521401 : msg.payload : number

23.5

1.9.2019, 23:12:05node: 68190ba5.39b3148A1579970203 : msg.payload : number

22.062

1.9.2019, 23:12:06node: 68190ba5.39b314AAF8E0521401 : msg.payload : number

23.5

1.9.2019, 23:12:10node: 68190ba5.39b3148A1579970203 : msg.payload : number

22

1.9.2019, 23:12:11node: 68190ba5.39b314AAF8E0521401 : msg.payload : number

23.437

1.9.2019, 23:12:16node: 68190ba5.39b3148A1579970203 : msg.payload : number

22.062

1.9.2019, 23:12:17node: 68190ba5.39b314AAF8E0521401 : msg.payload : number

23.437

1.9.2019, 23:12:20node: 68190ba5.39b3148A1579970203 : msg.payload : number

22.062

1.9.2019, 23:12:20node: 68190ba5.39b314AAF8E0521401 : msg.payload : number

23.437

1.9.2019, 23:12:27node: 68190ba5.39b3148A1579970203 : msg.payload : number

22

1.9.2019, 23:12:27node: 68190ba5.39b314AAF8E0521401 : msg.payload : number

23.437

1.9.2019, 23:12:30node: 68190ba5.39b3148A1579970203 : msg.payload : number

22

1.9.2019, 23:12:30node: 68190ba5.39b314AAF8E0521401 : msg.payload : number

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.

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

{ topic: "8A1579970203", payload: 21.75, _msgid: "4c041b5d.7be074", file: "28-03029779158a", dir: "w1_bus_master1" … }

1.9.2019, 23:19:48node: 68190ba5.39b314AAF8E0521401 : msg : Object

{ topic: "AAF8E0521401", payload: 23.187, _msgid: "4c041b5d.7be074", file: "28-011452e0f8aa", dir: "w1_bus_master1" … }

1.9.2019, 23:19:53node: 68190ba5.39b3148A1579970203 : msg : Object

{ topic: "8A1579970203", payload: 21.312, _msgid: "3b381108.2a1a6e", file: "28-03029779158a", dir: "w1_bus_master1" … }

1.9.2019, 23:19:53node: 68190ba5.39b314AAF8E0521401 : msg : Object

{ topic: "AAF8E0521401", payload: 23.187, _msgid: "3b381108.2a1a6e", file: "28-011452e0f8aa", dir: "w1_bus_master1" … }

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

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

2 Likes

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?