hi, I've connected a DS18B20 sensor to my RPi 3.
i made sure that the 1 wire is enabled on the Pi.
I've tried the following nodes:
node-red-contrib-ds18b20 ver. 0.0.3
node-red-contrib-ds18b20-sensor ver. 1.3.6
node-red-contrib-sensor-ds18b20 ver. 0.1.0
but in all of them i get the following massage: "msg.payload : undefined".
when I open the dropbox i see more then one sensor ID. whether the sensor is connected or not. there is no change when i switch between the sensor ID's. msg.payload is undefined.
It is a good idea to give debug nodes names so that it is clear which debug node the message came from.
Which node is that message coming from?
Which of the DS node types are you using in that image?
Please Export the relevant nodes and paste it here so we can see exactly what you are doing. When pasting click the </> button at the top of the forum entry window and paste it in.
in the pic I'm using the top ds18b20 node (the top one without the inject node).
[{"id":"bcecbc07.43b11","type":"tab","label":"Flow 2","disabled":false,"info":""},{"id":"eeb092e1.60de8","type":"debug","z":"bcecbc07.43b11","name":"sensor ds -18b20","active":false,"tosidebar":true,"console":false,"tostatus":false,"complete":"true","targetType":"full","statusVal":"","statusType":"auto","x":570,"y":80,"wires":[]},{"id":"1e74fb82.9c8b44","type":"debug","z":"bcecbc07.43b11","name":"ds18b20","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"payload","targetType":"msg","statusVal":"","statusType":"auto","x":540,"y":40,"wires":[]},{"id":"66a79bc.6a73564","type":"debug","z":"bcecbc07.43b11","name":"rpi-ds 18b20","active":false,"tosidebar":true,"console":false,"tostatus":false,"complete":"true","targetType":"full","statusVal":"","statusType":"auto","x":510,"y":120,"wires":[]},{"id":"56798d03.176654","type":"sensor-ds18b20","z":"bcecbc07.43b11","name":"","topic":"","sensorid":"00-100000000000","timer":"1","repeat":false,"x":350,"y":80,"wires":[["eeb092e1.60de8"]]},{"id":"c77a4c54.346b7","type":"ds18b20","z":"bcecbc07.43b11","name":"","sensorid":"00-b00000000000","timer":"0.1","x":350,"y":40,"wires":[["1e74fb82.9c8b44"]]},{"id":"1d31a519.47284b","type":"rpi-ds18b20","z":"bcecbc07.43b11","topic":"","array":false,"name":"","x":340,"y":120,"wires":[["66a79bc.6a73564"]]},{"id":"b3cbd639.1ed478","type":"inject","z":"bcecbc07.43b11","name":"","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"","payloadType":"date","x":160,"y":80,"wires":[["56798d03.176654"]]},{"id":"eb488a69.6ff868","type":"inject","z":"bcecbc07.43b11","name":"","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"","payloadType":"date","x":160,"y":120,"wires":[["1d31a519.47284b"]]}]
You haven't said which contrib node it is.
Don't have more than one installed at a time.
Edit: I meant which contrib node, I have corrected it.
Also change the debug node to show Complete Message and see if anything there.
node-red-contrib-sensor-ds18b20.
[{"id":"306cf019.3bb16","type":"tab","label":"Flow 1","disabled":false,"info":""},{"id":"449fc793.bd4648","type":"inject","z":"306cf019.3bb16","name":"","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"","payloadType":"date","x":100,"y":180,"wires":[["4328a186.e3a92"]]},{"id":"a2f55b7a.7097f8","type":"debug","z":"306cf019.3bb16","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"false","statusVal":"","statusType":"auto","x":450,"y":180,"wires":[]},{"id":"4328a186.e3a92","type":"sensor-ds18b20","z":"306cf019.3bb16","name":"","topic":"","sensorid":"00-a80000000000","timer":"1","repeat":false,"x":270,"y":180,"wires":[["a2f55b7a.7097f8"]]}]
as you can see it detects 3 sensors ids.
none works.
i get the same massage: msg.payload undefined
and do you have 3 sensors ?
Do you have the correct terminating resistor fitted ?
And it's wired to correct pins on pi ? 3.3V, Ground and signal.
The drop down box in the node is showing 3 sensor ID's, how many have you connected?
If you have connected more than one this is how they should be wired, note that only 1 resistor is needed.
I only want to use one sensor.
when I toke the picture nothing was connected to the Pi.
the same happens when I connect my sensor
this is my sensor:
And the resistor?
I think the resistor is my problem...
is this resistor will 4.7 KOhm, 1/4 W will be suited for the sensor?
That will be fine! Let us know how you get on!
You were right,
It was the resistor. Mine was not 4.7 KOhm.
When I replaced it with 4.7 the sensor started to work as it should...
Thank you.
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