# One node-red to another (different rpi's)
**URL:** https://discourse.nodered.org/t/one-node-red-to-another-different-rpis/3203
**Category:** General
**Created:** [17 September 2018 07:55 UTC](https://discourse.nodered.org/t/one-node-red-to-another-different-rpis/3203 "2018-09-17T07:55:12Z")
**Posts on this page:** 8
**Page:** 1
### Author:  [@matisok](https://discourse.nodered.org/u/matisok)
#### Post date: [17 September 2018 07:55 UTC](https://discourse.nodered.org/t/one-node-red-to-another-different-rpis/3203/1 "2018-09-17T07:55:12Z")
I have one RPi with a hardware buttons wired up to it that I would like to speak to another RPi with an output (controlling a HW relay) - both running node-red obviously.
How do I send a message from the one rpi to the other? They are on the same network.
M
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### Author:  [@dynamicdave](https://discourse.nodered.org/u/dynamicdave)
#### Post date: [17 September 2018 07:57 UTC](https://discourse.nodered.org/t/one-node-red-to-another-different-rpis/3203/2 "2018-09-17T07:57:38Z")
I think using MQTT would be your best bet/solution as it's quick and easy to set-up.
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### Author:  [@matisok](https://discourse.nodered.org/u/matisok)
#### Post date: [17 September 2018 07:59 UTC](https://discourse.nodered.org/t/one-node-red-to-another-different-rpis/3203/3 "2018-09-17T07:59:03Z")
I will have a play with that - thanks.
Btw, the Rpi's are not on a internet accessible network. (dont know if that makes a difference to the solution).
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### Author:  [@dynamicdave](https://discourse.nodered.org/u/dynamicdave)
#### Post date: [17 September 2018 08:01 UTC](https://discourse.nodered.org/t/one-node-red-to-another-different-rpis/3203/4 "2018-09-17T08:01:33Z")
That shouldn't matter - in fact it's safer.
Have a look at installing Mosquitto (MQTT broker) on both RPi, then you could use the MQTT In and Out nodes to transfer data between the Pi(es).
I think you should find a number of articles on the forum about what you are trying to do.
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### Author:  [@matisok](https://discourse.nodered.org/u/matisok)
#### Post date: [17 September 2018 09:12 UTC](https://discourse.nodered.org/t/one-node-red-to-another-different-rpis/3203/5 "2018-09-17T09:12:26Z")
Thanks again. So I need a broker on both pi's I take it?
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### Author:  [@knolleary](https://discourse.nodered.org/u/knolleary)
#### Post date: [17 September 2018 09:18 UTC](https://discourse.nodered.org/t/one-node-red-to-another-different-rpis/3203/6 "2018-09-17T09:18:52Z")
> [@matisok](#):
>
> So I need a broker on both pi's I take it?
No, you do not need a broker on both Pis.
You can pick one of your Pis to run the broker, and connect to it from all of the Pis (including itself).
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### Author:  [@matisok](https://discourse.nodered.org/u/matisok)
#### Post date: [17 September 2018 09:30 UTC](https://discourse.nodered.org/t/one-node-red-to-another-different-rpis/3203/7 "2018-09-17T09:30:25Z")
Awesome. It works.
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### Author:  [@TotallyInformation](https://discourse.nodered.org/u/TotallyInformation)
#### Post date: [18 September 2018 06:16 UTC](https://discourse.nodered.org/t/one-node-red-to-another-different-rpis/3203/8 "2018-09-18T06:16:04Z")
> [@matisok](#):
>
> Awesome. It works.
Just for reference, you could have used raw TCP, websocket or http nodes as well. All would work but undoubtedly, MQTT gives you a much more resilient solution without having to do the donkey work yourself.