# Enforce node to send zero value
**URL:** https://discourse.nodered.org/t/enforce-node-to-send-zero-value/5014
**Category:** General
**Created:** [19 November 2018 01:44 UTC](https://discourse.nodered.org/t/enforce-node-to-send-zero-value/5014 "2018-11-19T01:44:54Z")
**Posts on this page:** 7
**Page:** 1
### Author:  [@manal](https://discourse.nodered.org/u/manal)
#### Post date: [19 November 2018 01:44 UTC](https://discourse.nodered.org/t/enforce-node-to-send-zero-value/5014/1 "2018-11-19T01:44:54Z")
Hey there,
I use ds18b20 node in node-red to read sensor values directly, I want to write python code to enforce this node to send zero value instead of its real value. could you help me, please?
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### Author:  [@craigcurtin](https://discourse.nodered.org/u/craigcurtin)
#### Post date: [19 November 2018 02:07 UTC](https://discourse.nodered.org/t/enforce-node-to-send-zero-value/5014/2 "2018-11-19T02:07:46Z")
I assume this is on a Rpi ? Do you mean you want to ignore whatever value is coming in and then just send out a Zero instead - presumably sending it out on a MQTT topic ?
Not need to get python involved
Just use the change node
Craig
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### Author:  [@manal](https://discourse.nodered.org/u/manal)
#### Post date: [19 November 2018 02:12 UTC](https://discourse.nodered.org/t/enforce-node-to-send-zero-value/5014/3 "2018-11-19T02:12:18Z")
yes it is raspberry pi
I think python code is better, as I want this sensor send zero instead of its real value when I run python script, and when stop it then it return back to its normal situation ..
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### Author:  [@manal](https://discourse.nodered.org/u/manal)
#### Post date: [19 November 2018 05:31 UTC](https://discourse.nodered.org/t/enforce-node-to-send-zero-value/5014/4 "2018-11-19T05:31:14Z")
I don't like to change it through node-red by itself, I need to write python script and change it , so the node-red read the new value
can I change the value "t" in w1\_Slave? writing python code to set it zero each time, so node-red node reads this new values from w1\_Slave, or may this is not applicable and it doesn't work.
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### Author:  [@Colin](https://discourse.nodered.org/u/Colin)
#### Post date: [19 November 2018 07:12 UTC](https://discourse.nodered.org/t/enforce-node-to-send-zero-value/5014/5 "2018-11-19T07:12:05Z")
What is w1\_slave? Is that a variable in some code somewhere or what?
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### Author:  [@TotallyInformation](https://discourse.nodered.org/u/TotallyInformation)
#### Post date: [19 November 2018 07:16 UTC](https://discourse.nodered.org/t/enforce-node-to-send-zero-value/5014/6 "2018-11-19T07:16:34Z")
> [@manal](#):
>
> I don't like to change it through node-red by itself, I need to write python script and change it
This is not entirely a Node-RED question is it. You can do this purely in Node-RED and even have a switch that lets you turn on/off the zero flow if you wish.
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### Author:  [@manal](https://discourse.nodered.org/u/manal)
#### Post date: [19 November 2018 07:29 UTC](https://discourse.nodered.org/t/enforce-node-to-send-zero-value/5014/7 "2018-11-19T07:29:17Z")
ok. thanks. it is really not pure node-red question. I am sorry for that I will delete it