# General

**URL:** https://discourse.nodered.org/c/general/7.md?page=731

[Latest](https://discourse.nodered.org/latest.md) · [Categories](https://discourse.nodered.org/categories.md) · [Tags](https://discourse.nodered.org/tags.md)

**Page:** 732

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## [Why can't the serial palette be installed](https://discourse.nodered.org/t/why-cant-the-serial-palette-be-installed/28521)

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**Author:** [@Dimas](https://discourse.nodered.org/u/Dimas)\
**Replies:** 10\
**Last updated:** [18 June 2020 10:43 UTC](https://discourse.nodered.org/t/why-cant-the-serial-palette-be-installed/28521 "2020-06-18T10:43:32Z")

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sir, is there a solution about this problem ?

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## [To many mqtt broker - how to delete some of them?](https://discourse.nodered.org/t/to-many-mqtt-broker-how-to-delete-some-of-them/28533)

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**Author:** [@juntiedt](https://discourse.nodered.org/u/juntiedt)\
**Replies:** 7\
**Last updated:** [18 June 2020 10:10 UTC](https://discourse.nodered.org/t/to-many-mqtt-broker-how-to-delete-some-of-them/28533 "2020-06-18T10:10:17Z")

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unfortunately I have to many mqtt broker configured in the mqtt node when I started using mqtt. How can I delete the unused brokers?

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## [Saving context variable to the localfilesystem immediately on change](https://discourse.nodered.org/t/saving-context-variable-to-the-localfilesystem-immediately-on-change/28515)

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**Author:** [@kushan-athukorala](https://discourse.nodered.org/u/kushan-athukorala)\
**Replies:** 10\
**Last updated:** [18 June 2020 08:56 UTC](https://discourse.nodered.org/t/saving-context-variable-to-the-localfilesystem-immediately-on-change/28515 "2020-06-18T08:56:04Z")

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Hi, I have my node-red flow configured to use localfilesystem as contextStorage. I know that for every 30 seconds context variables are saved to the file system. Is there a way to save these immediately to the file sys…

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## [Access to the Dashboard from outside and inside your home](https://discourse.nodered.org/t/access-to-the-dashboard-from-outside-and-inside-your-home/26592)

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**Author:** [@Jean-Luc](https://discourse.nodered.org/u/Jean-Luc)\
**Replies:** 15\
**Last updated:** [18 June 2020 07:49 UTC](https://discourse.nodered.org/t/access-to-the-dashboard-from-outside-and-inside-your-home/26592 "2020-06-18T07:49:58Z")

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What is the best solution? (This for a neophyte) Ok, you have easily installed your Letsencrypt certificates with the node-red-contrib-acme-client node, performed port forwarding in your router. External access is ok v…

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## [Indexing into flow/global scope array element using variable](https://discourse.nodered.org/t/indexing-into-flow-global-scope-array-element-using-variable/28518)

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**Author:** [@Eric](https://discourse.nodered.org/u/Eric)\
**Replies:** 1\
**Last updated:** [18 June 2020 06:40 UTC](https://discourse.nodered.org/t/indexing-into-flow-global-scope-array-element-using-variable/28518 "2020-06-18T06:40:07Z")

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I have a flow scoped array that I initialized like this: flow.set('status',\[true,true,true,true,true,true,true,true,true,true\]); Later on, I'm doing some processing to figure out which element of that array I want to m…

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## [DNS address assignment on the internal network](https://discourse.nodered.org/t/dns-address-assignment-on-the-internal-network/28511)

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**Author:** [@Joaovitor](https://discourse.nodered.org/u/Joaovitor)\
**Replies:** 2\
**Last updated:** [18 June 2020 06:04 UTC](https://discourse.nodered.org/t/dns-address-assignment-on-the-internal-network/28511 "2020-06-18T06:04:59Z")

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Well, I am running node-RED on my local machine. I can access node-RED easily from other devices, but I have a problem: it is common for the router to assign my machine (pc with win 10) from time to time dynamic ip addr…

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## [Using arrayFilter option in node-red-mongodb node in node-red](https://discourse.nodered.org/t/using-arrayfilter-option-in-node-red-mongodb-node-in-node-red/26573)

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**Author:** [@kushan-athukorala](https://discourse.nodered.org/u/kushan-athukorala)\
**Replies:** 3\
**Last updated:** [18 June 2020 03:59 UTC](https://discourse.nodered.org/t/using-arrayfilter-option-in-node-red-mongodb-node-in-node-red/26573 "2020-06-18T03:59:51Z")

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Hi, I want to update an specific array element in a mongodb document. How can I pass arrayFilter option to the mongodb node when I do the update. Thanks, Kushan

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## [How long does my IP stay in the router's ARP table?](https://discourse.nodered.org/t/how-long-does-my-ip-stay-in-the-routers-arp-table/28437)

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**Author:** [@SteveMann](https://discourse.nodered.org/u/SteveMann)\
**Replies:** 18\
**Last updated:** [18 June 2020 03:11 UTC](https://discourse.nodered.org/t/how-long-does-my-ip-stay-in-the-routers-arp-table/28437 "2020-06-18T03:11:41Z")

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I asked this morning about finding my MAC address in the output of the ARP node: Find an object in an array of objects I got a lot of really good suggestions that led me to my solution. My goal is to detect when my ph…

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## [Node to stop Google Home playing music](https://discourse.nodered.org/t/node-to-stop-google-home-playing-music/28455)

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**Author:** [@Roaders](https://discourse.nodered.org/u/Roaders)\
**Replies:** 1\
**Last updated:** [18 June 2020 02:37 UTC](https://discourse.nodered.org/t/node-to-stop-google-home-playing-music/28455 "2020-06-18T02:37:16Z")

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Hi All I have hue lights, a hue dimmer switch and a google home in pretty much every room in my house. When I leave the room I turn the lights off with the dimmer switch (which is hooked up to node red) but I have to as…

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## [Alexa-remote2 not supplying all requests reliably and other issues with it](https://discourse.nodered.org/t/alexa-remote2-not-supplying-all-requests-reliably-and-other-issues-with-it/24403)

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**Author:** [@cymplecy](https://discourse.nodered.org/u/cymplecy)\
**Replies:** 50\
**Last updated:** [17 June 2020 22:37 UTC](https://discourse.nodered.org/t/alexa-remote2-not-supplying-all-requests-reliably-and-other-issues-with-it/24403 "2020-06-17T22:37:13Z")

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I've been using alexa-remote2 a bit recently (coupled with the Q&A skill) as per this useful thread but I'm finding its not quite reliable enough (compared to using @hardillb node-red-contrib-alexa-home-skill (node) …

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## [Node red with arduino](https://discourse.nodered.org/t/node-red-with-arduino/28438)

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**Author:** [@ugoo](https://discourse.nodered.org/u/ugoo)\
**Replies:** 3\
**Last updated:** [17 June 2020 17:55 UTC](https://discourse.nodered.org/t/node-red-with-arduino/28438 "2020-06-17T17:55:05Z")

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bonjour,je m'appelle ugo et je viens de commencer un projet en domotique avec un raspberry pi et un arduino (branché en série). Afin de pouvoir générer une interface web j'ai choisis de l'utilisation de node red. tout …

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## [Include external subflow?](https://discourse.nodered.org/t/include-external-subflow/28483)

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**Author:** [@Colin](https://discourse.nodered.org/u/Colin)\
**Replies:** 2\
**Last updated:** [17 June 2020 16:19 UTC](https://discourse.nodered.org/t/include-external-subflow/28483 "2020-06-17T16:19:58Z")

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Is there any way to include a subflow from elsewhere? I have some subflows that I use on multiple systems and would really like to have a way of having a master copy (which would be git controlled) and somehow automatic…

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## [Seemingly trivial calculation does not work](https://discourse.nodered.org/t/seemingly-trivial-calculation-does-not-work/28465)

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**Author:** [@mcaklein](https://discourse.nodered.org/u/mcaklein)\
**Replies:** 18\
**Last updated:** [17 June 2020 15:28 UTC](https://discourse.nodered.org/t/seemingly-trivial-calculation-does-not-work/28465 "2020-06-17T15:28:23Z")

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Hi all, I measure the yield of my solar panels and created a Telegram interface. However, there is one problem I'm not able to solve... This is the situation. The incoming MQTT message contains the total yield and I wa…

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## [External flows.json generation](https://discourse.nodered.org/t/external-flows-json-generation/28484)

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**Author:** [@wolfred](https://discourse.nodered.org/u/wolfred)\
**Replies:** 0\
**Last updated:** [17 June 2020 15:16 UTC](https://discourse.nodered.org/t/external-flows-json-generation/28484 "2020-06-17T15:16:06Z")

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We use Node-RED for connecting industrial machines via Modbus and OPC/UA to a MQTT broker. There are different connection parameters and data processing requirements (transformation, filtering,...) for each machine. Curr…

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## [Code works in function, but not in a Change Node?](https://discourse.nodered.org/t/code-works-in-function-but-not-in-a-change-node/28382)

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**Author:** [@Nodi.Rubrum](https://discourse.nodered.org/u/Nodi.Rubrum)\
**Replies:** 4\
**Last updated:** [17 June 2020 14:33 UTC](https://discourse.nodered.org/t/code-works-in-function-but-not-in-a-change-node/28382 "2020-06-17T14:33:47Z")

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I am new to node red, but been a system designer, extensive code designer on many systems, etc. Well I guess you get the picture, I know programming and many languages. But I digress. Below are three(3) simple flows. …

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## [Editor - colored keywords](https://discourse.nodered.org/t/editor-colored-keywords/28456)

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**Author:** [@softy2k](https://discourse.nodered.org/u/softy2k)\
**Replies:** 2\
**Last updated:** [17 June 2020 10:08 UTC](https://discourse.nodered.org/t/editor-colored-keywords/28456 "2020-06-17T10:08:28Z")

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In Editor, most reserved keywords are automatically colored. But, there are some that are (not yet) colored, such as: hasOwnProperty, trim (msg.payload.trim ()) etc. What is the possibility of them being colored automa…

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## [Switch to presence](https://discourse.nodered.org/t/switch-to-presence/28109)

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**Author:** [@Vlak](https://discourse.nodered.org/u/Vlak)\
**Replies:** 17\
**Last updated:** [17 June 2020 09:30 UTC](https://discourse.nodered.org/t/switch-to-presence/28109 "2020-06-17T09:30:22Z")

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Dear people, I want to create a flow using a device tracker. I want to have a cover closed when I'm not home at a certain time. And I want this same cover to stay open when I am at home. I don't expect this to be very…

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## [Node red running in ubuntu crashed](https://discourse.nodered.org/t/node-red-running-in-ubuntu-crashed/28440)

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**Author:** [@neelanjan](https://discourse.nodered.org/u/neelanjan)\
**Replies:** 2\
**Last updated:** [17 June 2020 07:35 UTC](https://discourse.nodered.org/t/node-red-running-in-ubuntu-crashed/28440 "2020-06-17T07:35:52Z")

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Hi, I was running nodered in ubuntu.Due to some error node red crashed and all the latest developments along with some flow got deleted. Please tell me a way to find the flows and get all my recent codes. Thanks in ad…

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## [After receiving message generate each second a message for 10 minutes](https://discourse.nodered.org/t/after-receiving-message-generate-each-second-a-message-for-10-minutes/28426)

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**Author:** [@JSONata](https://discourse.nodered.org/u/JSONata)\
**Replies:** 3\
**Last updated:** [17 June 2020 06:01 UTC](https://discourse.nodered.org/t/after-receiving-message-generate-each-second-a-message-for-10-minutes/28426 "2020-06-17T06:01:14Z")

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So after a message arrives (content is irrelevant) a node starts so send for 10 minutes a message each second. How is this possible? Doing a for loop sending via node.send? https://nodered.org/docs/user-guide/writing-fu…

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## [Last triggered is more the 2 days before current date](https://discourse.nodered.org/t/last-triggered-is-more-the-2-days-before-current-date/28374)

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**Author:** [@fxxer](https://discourse.nodered.org/u/fxxer)\
**Replies:** 14\
**Last updated:** [17 June 2020 04:30 UTC](https://discourse.nodered.org/t/last-triggered-is-more-the-2-days-before-current-date/28374 "2020-06-17T04:30:26Z")

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Hi, I am trying to calculate time difference between last\_triggered time of a HA script with current date. I am stuck how to do it. Can anyone help me? I want to flow to continue only if the last triggered time to curre…

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## [Easily adding AI capabilities to your flows](https://discourse.nodered.org/t/easily-adding-ai-capabilities-to-your-flows/28444)

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**Author:** [@kfiry](https://discourse.nodered.org/u/kfiry)\
**Replies:** 0\
**Last updated:** [17 June 2020 00:46 UTC](https://discourse.nodered.org/t/easily-adding-ai-capabilities-to-your-flows/28444 "2020-06-17T00:46:47Z")

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Hello everyone! :wave: I’m Kfir and as the Head of Product at an AI startup (Veritone), I thought you might find what we’ve been working on with Automate Studio interesting for this community. In the last few years of b…

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## [Docker on Synology](https://discourse.nodered.org/t/docker-on-synology/28370)

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**Author:** [@Goofy2k](https://discourse.nodered.org/u/Goofy2k)\
**Replies:** 3\
**Last updated:** [16 June 2020 21:43 UTC](https://discourse.nodered.org/t/docker-on-synology/28370 "2020-06-16T21:43:07Z")

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Hi, I am trying to persist the user data when running NR under Docker on my Synology NAS. I want to use a host directory (Bind Mount) I followed the instructions on Github without succes. I went to the WIKI and followed …

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## [Customize the basic mqtt node](https://discourse.nodered.org/t/customize-the-basic-mqtt-node/28401)

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**Author:** [@vp2021](https://discourse.nodered.org/u/vp2021)\
**Replies:** 2\
**Last updated:** [16 June 2020 21:21 UTC](https://discourse.nodered.org/t/customize-the-basic-mqtt-node/28401 "2020-06-16T21:21:52Z")

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Hello, I want to use the basic components "MQTT IN" and "MQTT OUT" and modify them a bit in order to have other possible attributes in their properties. Where can I find their basic files (.js, .html, .json) so that I …

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## [Searching a sea weather website](https://discourse.nodered.org/t/searching-a-sea-weather-website/28357)

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**Author:** [@Fati](https://discourse.nodered.org/u/Fati)\
**Replies:** 11\
**Last updated:** [16 June 2020 20:19 UTC](https://discourse.nodered.org/t/searching-a-sea-weather-website/28357 "2020-06-16T20:19:00Z")

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Hello! can someone help me! I search a web site of sea ​​weather(high tide periods,the heights of the swells,rainy periods) in json format. The api.openweathermap.org can't offer this type of weather

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## [Got Error 2 while trying to execute a python file in Exec node](https://discourse.nodered.org/t/got-error-2-while-trying-to-execute-a-python-file-in-exec-node/27889)

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**Author:** [@karlo](https://discourse.nodered.org/u/karlo)\
**Replies:** 2\
**Last updated:** [16 June 2020 19:16 UTC](https://discourse.nodered.org/t/got-error-2-while-trying-to-execute-a-python-file-in-exec-node/27889 "2020-06-16T19:16:51Z")

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Hello, I'm trying to execute a python file, that can be found under the absolute path. But I only get the Error: 2 How can I retrieve more error messages and what is the Problem? Thank you very much!! Node-RED|690x…

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## [Problem sending array from function to table](https://discourse.nodered.org/t/problem-sending-array-from-function-to-table/28313)

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**Author:** [@aidan](https://discourse.nodered.org/u/aidan)\
**Replies:** 2\
**Last updated:** [16 June 2020 16:20 UTC](https://discourse.nodered.org/t/problem-sending-array-from-function-to-table/28313 "2020-06-16T16:20:42Z")

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I am sending object arrays to tables. I have to pad function node with a dummy output to get the first table to update consistently. The output line is as below. It must be a timing problem because just returning 'null…

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## [Can't Stage Changes in a Node-RED Project](https://discourse.nodered.org/t/cant-stage-changes-in-a-node-red-project/28421)

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**Author:** [@dudleyjosh](https://discourse.nodered.org/u/dudleyjosh)\
**Replies:** 2\
**Last updated:** [16 June 2020 15:56 UTC](https://discourse.nodered.org/t/cant-stage-changes-in-a-node-red-project/28421 "2020-06-16T15:56:07Z")

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I have a Raspberry Pi setup using Node-RED projects (running v1.0.6) and have committed and pushed changes to my GitHub repository in the past without issue. After making some recent updates to my flows, I went to commit…

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## [Issue with Heater node, not heating](https://discourse.nodered.org/t/issue-with-heater-node-not-heating/28409)

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**Author:** [@Keirtje](https://discourse.nodered.org/u/Keirtje)\
**Replies:** 10\
**Last updated:** [16 June 2020 15:18 UTC](https://discourse.nodered.org/t/issue-with-heater-node-not-heating/28409 "2020-06-16T15:18:39Z")

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Hi, as not all to experience with Node Red, I am having an issue with the node-red-contrib-heater-controller. All works fine, but how does it turn on my heater? The node will work just fine on my dashboard, temperatures…

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## [Activate a node when closing](https://discourse.nodered.org/t/activate-a-node-when-closing/28396)

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**Author:** [@Hattori](https://discourse.nodered.org/u/Hattori)\
**Replies:** 5\
**Last updated:** [16 June 2020 14:39 UTC](https://discourse.nodered.org/t/activate-a-node-when-closing/28396 "2020-06-16T14:39:32Z")

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Hello, I am new to Node-red and i am looking for a node that can be launched when the main window is closing so that i can clean up some project contents. I searched for something like this but did not find anything.

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## [\<solved\> Find an object in an array of objects](https://discourse.nodered.org/t/solved-find-an-object-in-an-array-of-objects/28384)

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**Author:** [@SteveMann](https://discourse.nodered.org/u/SteveMann)\
**Replies:** 17\
**Last updated:** [16 June 2020 14:17 UTC](https://discourse.nodered.org/t/solved-find-an-object-in-an-array-of-objects/28384 "2020-06-16T14:17:13Z")

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My goal is to detect when my phone or my wife's phone is at home or not. One way I thought of was to use the ARP node to get all of the IP and MAC addresses in my router's ARP table, then look for our phones. If there'…

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