# General

**URL:** https://discourse.nodered.org/c/general/7.md?page=436

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

**Page:** 437

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## [Function node with a timer (stored in Flow variable to maintain state) - doesn't work](https://discourse.nodered.org/t/function-node-with-a-timer-stored-in-flow-variable-to-maintain-state-doesnt-work/56436)

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**Author:** [@Noh](https://discourse.nodered.org/u/Noh)\
**Replies:** 10\
**Last updated:** [19 January 2022 20:39 UTC](https://discourse.nodered.org/t/function-node-with-a-timer-stored-in-flow-variable-to-maintain-state-doesnt-work/56436 "2022-01-19T20:39:35Z")

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Am I correct to use Date.Now() to capture seconds since epoch? In the last stanza of this code from my function node I check whether Date.Now() (for actual now!) minus Flow variable startTimer (Date.Now() from when the …

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## [Updating Node-Red on a PI](https://discourse.nodered.org/t/updating-node-red-on-a-pi/14507)

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**Author:** [@Poodlepapa](https://discourse.nodered.org/u/Poodlepapa)\
**Replies:** 8\
**Last updated:** [19 January 2022 18:42 UTC](https://discourse.nodered.org/t/updating-node-red-on-a-pi/14507 "2022-01-19T18:42:39Z")

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Is this the best way to update Node-Red on a raspberry pi? update-nodejs-and-nodered? And is there a way to get it to install nodes that I commonly use a batch rather than clicking on them individually in the Pallet Mana…

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## [Node-red-contrib-s7 variables defined dynamically](https://discourse.nodered.org/t/node-red-contrib-s7-variables-defined-dynamically/56921)

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**Author:** [@FabioT](https://discourse.nodered.org/u/FabioT)\
**Replies:** 0\
**Last updated:** [19 January 2022 15:12 UTC](https://discourse.nodered.org/t/node-red-contrib-s7-variables-defined-dynamically/56921 "2022-01-19T15:12:50Z")

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Hi All, is there a way, working with "node-red-contrib-s7" nodes, to do not define PLC variables in a static way as defined in attached image? I would like to pass the plc variables list as a json file to the s7-in nod…

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## [Epoch Time subtraction](https://discourse.nodered.org/t/epoch-time-subtraction/56872)

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**Author:** [@JHScen](https://discourse.nodered.org/u/JHScen)\
**Replies:** 23\
**Last updated:** [19 January 2022 14:45 UTC](https://discourse.nodered.org/t/epoch-time-subtraction/56872 "2022-01-19T14:45:40Z")

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I am trying to do a simple subtraction of time in a function node. The elements of time include; current time, minus 'time since last motion'. Both of these are formatted in epoch time. The issue that I am having is th…

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## [TLS config for https request - question](https://discourse.nodered.org/t/tls-config-for-https-request-question/56911)

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**Author:** [@lilouch](https://discourse.nodered.org/u/lilouch)\
**Replies:** 0\
**Last updated:** [19 January 2022 09:01 UTC](https://discourse.nodered.org/t/tls-config-for-https-request-question/56911 "2022-01-19T09:01:51Z")

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Hi, I have a network gateway with node red installed on it. I can access to the node red dashboard. So far so good. The idea is when I receive new data, I send them to my server. So I have a node that is "htt request …

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## [Exec command does not work like the same command in the cli](https://discourse.nodered.org/t/exec-command-does-not-work-like-the-same-command-in-the-cli/56835)

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**Author:** [@shrickus](https://discourse.nodered.org/u/shrickus)\
**Replies:** 12\
**Last updated:** [19 January 2022 06:49 UTC](https://discourse.nodered.org/t/exec-command-does-not-work-like-the-same-command-in-the-cli/56835 "2022-01-19T06:49:15Z")

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Ok, I've wasted too much time on this "espeak" exec node... has anyone seen this before? This command works fine using my login from the command line on my rpi4 running ubuntu 10.20: srickus@shrpi4:~$ espeak -ven+f4…

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## [Volume control node-red-contrib-sox-utils](https://discourse.nodered.org/t/volume-control-node-red-contrib-sox-utils/56792)

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**Author:** [@Janik](https://discourse.nodered.org/u/Janik)\
**Replies:** 3\
**Last updated:** [19 January 2022 06:41 UTC](https://discourse.nodered.org/t/volume-control-node-red-contrib-sox-utils/56792 "2022-01-19T06:41:51Z")

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Is there a possibility to control the volume of the audio played by the sox-play node of node-red-contrib-sox-utils with a msg? I know I can change the gain in dB in the Output settings but I want to control the volume …

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## [Sending "s" key press or CTRL+C to Daemon process](https://discourse.nodered.org/t/sending-s-key-press-or-ctrl-c-to-daemon-process/56748)

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**Author:** [@cedschmidt](https://discourse.nodered.org/u/cedschmidt)\
**Replies:** 3\
**Last updated:** [18 January 2022 23:21 UTC](https://discourse.nodered.org/t/sending-s-key-press-or-ctrl-c-to-daemon-process/56748 "2022-01-18T23:21:05Z")

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Hi everyone, I'm trying to run fmedia from node red under windows 10 to record speeches. I can easily start recording from a Daemon node, but to stop recording I need to press S key or CTRL+C command (in terminal) and …

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## [Where to install Node-red](https://discourse.nodered.org/t/where-to-install-node-red/56883)

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**Author:** [@martinjubb](https://discourse.nodered.org/u/martinjubb)\
**Replies:** 15\
**Last updated:** [18 January 2022 21:54 UTC](https://discourse.nodered.org/t/where-to-install-node-red/56883 "2022-01-18T21:54:17Z")

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Hi everyone. I am new to Node-Red and want to know where best to install the program. I have an Emonpi for energy monitoring. I also have a Raspberry Pi 4 running Home Assistant that is very much a work in progress I…

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## [Trigger a Delay Node Release](https://discourse.nodered.org/t/trigger-a-delay-node-release/56884)

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**Author:** [@zane](https://discourse.nodered.org/u/zane)\
**Replies:** 2\
**Last updated:** [18 January 2022 21:24 UTC](https://discourse.nodered.org/t/trigger-a-delay-node-release/56884 "2022-01-18T21:24:51Z")

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I have a delay node set to release every hour. But every now and then I want to make it happen early, is there a way to allow it manually to happen earlier?

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## [Servo motor control using PCA9685](https://discourse.nodered.org/t/servo-motor-control-using-pca9685/56870)

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**Author:** [@caiomac](https://discourse.nodered.org/u/caiomac)\
**Replies:** 1\
**Last updated:** [18 January 2022 20:47 UTC](https://discourse.nodered.org/t/servo-motor-control-using-pca9685/56870 "2022-01-18T20:47:04Z")

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I'm new to nodered, I would like to know how to drive a servo motor. I'm using a pc9685.

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## [DICOM to PNG error](https://discourse.nodered.org/t/dicom-to-png-error/56708)

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**Author:** [@thejollypop](https://discourse.nodered.org/u/thejollypop)\
**Replies:** 3\
**Last updated:** [18 January 2022 17:16 UTC](https://discourse.nodered.org/t/dicom-to-png-error/56708 "2022-01-18T17:16:58Z")

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Hey everyone, So I have DICOM medical images I want to convert and view as PNG, without cropping or resizing. It uses an external function - npm , but I get a rendering error which indicates something is missing in the …

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## [Alexa read data when requested](https://discourse.nodered.org/t/alexa-read-data-when-requested/56453)

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**Author:** [@smart\_hendrik](https://discourse.nodered.org/u/smart_hendrik)\
**Replies:** 12\
**Last updated:** [18 January 2022 15:31 UTC](https://discourse.nodered.org/t/alexa-read-data-when-requested/56453 "2022-01-18T15:31:43Z")

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Hello all, I've been working with NodeRed since yesterday and I'm excited about the functionality. After some initial difficulties I managed to query a variable (temperature) of my heating boiler. The whole heating syst…

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## ["UDP in" setting port dynamically](https://discourse.nodered.org/t/udp-in-setting-port-dynamically/56839)

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**Author:** [@wepa](https://discourse.nodered.org/u/wepa)\
**Replies:** 7\
**Last updated:** [18 January 2022 14:18 UTC](https://discourse.nodered.org/t/udp-in-setting-port-dynamically/56839 "2022-01-18T14:18:47Z")

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Online help says: However, the node does not consider a msg.port variable (unlike "UDP out"). Is there any workaround for that(?)

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## [Convert string in array to value](https://discourse.nodered.org/t/convert-string-in-array-to-value/56850)

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**Author:** [@WeSleY](https://discourse.nodered.org/u/WeSleY)\
**Replies:** 14\
**Last updated:** [18 January 2022 14:13 UTC](https://discourse.nodered.org/t/convert-string-in-array-to-value/56850 "2022-01-18T14:13:28Z")

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Hello, I am new to the forum. I'm Wesley, 38 years old and have been working on home automation for a while now. Recently I did an integration with node-red and the PLC. Everything is working well. Now in Belgium the e…

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## [SSH access to sensor data - ad User ´pi´ and Password to EXEC Node](https://discourse.nodered.org/t/ssh-access-to-sensor-data-ad-user-pi-and-password-to-exec-node/56858)

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**Author:** [@smart\_hendrik](https://discourse.nodered.org/u/smart_hendrik)\
**Replies:** 3\
**Last updated:** [18 January 2022 13:22 UTC](https://discourse.nodered.org/t/ssh-access-to-sensor-data-ad-user-pi-and-password-to-exec-node/56858 "2022-01-18T13:22:34Z")

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Hello all, I have my node red installation running on a NAS. Now I want to realize SSH access to sensor data of my RaspberryPI in the same network. Normally the access is done via Putty: I know that I can execute a…

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## [Why is the result always false?](https://discourse.nodered.org/t/why-is-the-result-always-false/56808)

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**Author:** [@hermiot](https://discourse.nodered.org/u/hermiot)\
**Replies:** 3\
**Last updated:** [18 January 2022 13:11 UTC](https://discourse.nodered.org/t/why-is-the-result-always-false/56808 "2022-01-18T13:11:46Z")

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Hi, why is the output always false instead of true, as it is defined? var CO2 = msg.payload; var L1 = { payload: { On: msg.payload.On === true}} var L2 = { payload: { On: msg.payload.On === true}} var …

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## [How to create a timestamp in the right format for a dashboard chart](https://discourse.nodered.org/t/how-to-create-a-timestamp-in-the-right-format-for-a-dashboard-chart/56749)

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**Author:** [@nodenoob](https://discourse.nodered.org/u/nodenoob)\
**Replies:** 11\
**Last updated:** [18 January 2022 12:56 UTC](https://discourse.nodered.org/t/how-to-create-a-timestamp-in-the-right-format-for-a-dashboard-chart/56749 "2022-01-18T12:56:14Z")

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The question may sounds dumb, I am an absolute beginner. So I want to store data in a csv file, and later on I want to display this data through a chart. I already tried to make a timestamp with msg.payload.timestamp = …

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## [Values flickers](https://discourse.nodered.org/t/values-flickers/56769)

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**Author:** [@dannysotzny](https://discourse.nodered.org/u/dannysotzny)\
**Replies:** 5\
**Last updated:** [18 January 2022 11:58 UTC](https://discourse.nodered.org/t/values-flickers/56769 "2022-01-18T11:58:33Z")

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Hello, I have a data point in ioBroker that shows the online status. Apparently this is set to FALSE before the start of the check and is then TRUE a few milliseconds later. Is there already a node which remembers the …

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## [Join - Not working to plan](https://discourse.nodered.org/t/join-not-working-to-plan/56791)

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**Author:** [@ScheepersJohan](https://discourse.nodered.org/u/ScheepersJohan)\
**Replies:** 10\
**Last updated:** [18 January 2022 11:35 UTC](https://discourse.nodered.org/t/join-not-working-to-plan/56791 "2022-01-18T11:35:01Z")

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I have a flow calling data from a postgresql. The table have two field - (sent SERIAL PRIMARY KEY, sentype jsonb); I currently have only two entries. The call to the DB I receive the array containing all the data. ob…

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## [Function node, edit message is not working in database](https://discourse.nodered.org/t/function-node-edit-message-is-not-working-in-database/56846)

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**Author:** [@josemspedro](https://discourse.nodered.org/u/josemspedro)\
**Replies:** 2\
**Last updated:** [18 January 2022 11:14 UTC](https://discourse.nodered.org/t/function-node-edit-message-is-not-working-in-database/56846 "2022-01-18T11:14:30Z")

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Hello, I am using the nodes in the picture below to write an integer in a label(dashboard) and write it in a database. You can see the code of the function node in the picture to Update the database with the variabl…

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## [RasPi 3B+ help with \`led1\` functionallity](https://discourse.nodered.org/t/raspi-3b-help-with-led1-functionallity/56770)

<div class="topic-metadata">

**Author:** [@Trying\_to\_learn](https://discourse.nodered.org/u/Trying_to_learn)\
**Replies:** 2\
**Last updated:** [18 January 2022 09:18 UTC](https://discourse.nodered.org/t/raspi-3b-help-with-led1-functionallity/56770 "2022-01-18T09:18:44Z")

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Maybe off topic, but I have to ask somewhere. I can control the activity LED by writing a different value to /sys/class/leds/led1/brightness 0 if off and 1 is on. Normally I want it off and only on after a reboot, un…

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## [Copy path of a variable from Debug Node does not work](https://discourse.nodered.org/t/copy-path-of-a-variable-from-debug-node-does-not-work/56841)

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**Author:** [@smart\_hendrik](https://discourse.nodered.org/u/smart_hendrik)\
**Replies:** 7\
**Last updated:** [18 January 2022 08:51 UTC](https://discourse.nodered.org/t/copy-path-of-a-variable-from-debug-node-does-not-work/56841 "2022-01-18T08:51:20Z")

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Hello all, I have a quick question for you - maybe someone already had the same problem...! I regularly use the debug Node and search for a variable in a XML file to copy the path. In the beginning this worked great, n…

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## [Configure Modbus flex server from ui dashboard](https://discourse.nodered.org/t/configure-modbus-flex-server-from-ui-dashboard/56771)

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**Author:** [@zyx09](https://discourse.nodered.org/u/zyx09)\
**Replies:** 2\
**Last updated:** [18 January 2022 04:13 UTC](https://discourse.nodered.org/t/configure-modbus-flex-server-from-ui-dashboard/56771 "2022-01-18T04:13:42Z")

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I had done ui dashboard to configure modbus client node via flex connector. But to configure modbus flex server, i no ideal how to do it, I can't find any similar subject on forum. Did anyone have done it? Thank you.

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## [Javascript: decide about multiple vars - any idea how maintain it more easy?](https://discourse.nodered.org/t/javascript-decide-about-multiple-vars-any-idea-how-maintain-it-more-easy/56754)

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**Author:** [@Mannshoch](https://discourse.nodered.org/u/Mannshoch)\
**Replies:** 10\
**Last updated:** [18 January 2022 03:31 UTC](https://discourse.nodered.org/t/javascript-decide-about-multiple-vars-any-idea-how-maintain-it-more-easy/56754 "2022-01-18T03:31:39Z")

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I have around six vars. Depending on their condition (true/false) I have to return something. Should I do it that way: if (msg.payload.on == true && global.get("Var") == true && ...) { } or if (msg.payload.on == true…

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## [Pushover WAY too slow?](https://discourse.nodered.org/t/pushover-way-too-slow/56740)

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**Author:** [@scargill](https://discourse.nodered.org/u/scargill)\
**Replies:** 28\
**Last updated:** [18 January 2022 01:49 UTC](https://discourse.nodered.org/t/pushover-way-too-slow/56740 "2022-01-18T01:49:50Z")

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Does anyone (DCJAY, Knolleary?) know why PUSHOVER is so SLOW? I have my Raspberry Pi 4 setup, and Amazon Polly - Node-Red talks to Polly (exec node) and when one of 2 doors (my office or the front door) opens, she respo…

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## [Best notification app on android?](https://discourse.nodered.org/t/best-notification-app-on-android/16809)

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**Author:** [@yusuv](https://discourse.nodered.org/u/yusuv)\
**Replies:** 50\
**Last updated:** [17 January 2022 23:36 UTC](https://discourse.nodered.org/t/best-notification-app-on-android/16809 "2022-01-17T23:36:25Z")

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Hello guys, what the best app to sending notification from node.js / node-red to android device ? except Pushbullet app. Thanks

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## [Which library does Node-RED use for its diagrams?](https://discourse.nodered.org/t/which-library-does-node-red-use-for-its-diagrams/56821)

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**Author:** [@richardtallent](https://discourse.nodered.org/u/richardtallent)\
**Replies:** 2\
**Last updated:** [17 January 2022 22:50 UTC](https://discourse.nodered.org/t/which-library-does-node-red-use-for-its-diagrams/56821 "2022-01-17T22:50:31Z")

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I'm a software developer, I use Node-RED for home automation, and I'm really impressed with the UI. Does Node-RED use an underlying npm library for its node dragging, dropping, and connecting, or is the entire thing par…

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## [How to only pass through a certain part of an array?](https://discourse.nodered.org/t/how-to-only-pass-through-a-certain-part-of-an-array/56766)

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**Author:** [@haavardbj](https://discourse.nodered.org/u/haavardbj)\
**Replies:** 8\
**Last updated:** [17 January 2022 20:30 UTC](https://discourse.nodered.org/t/how-to-only-pass-through-a-certain-part-of-an-array/56766 "2022-01-17T20:30:21Z")

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Hi I have a node sending data from a energy-meter. The data that i recieve is delivered like this. Delivery 1: an array of data, Delivery 2. a given value (1 line of the array) Delivery 3: a given value (1 line of …

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## [Auto start node-red on boot using termux on Android 10](https://discourse.nodered.org/t/auto-start-node-red-on-boot-using-termux-on-android-10/56805)

<div class="topic-metadata">

**Author:** [@lfilipe](https://discourse.nodered.org/u/lfilipe)\
**Replies:** 6\
**Last updated:** [17 January 2022 20:18 UTC](https://discourse.nodered.org/t/auto-start-node-red-on-boot-using-termux-on-android-10/56805 "2022-01-17T20:18:42Z")

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Hi guys, I want to run a node-red flow in Kiosk mode on my tablet (android 10) and for that I need to run node-red on boot. I tried termux:boot already, I did all the steps required but without success. If anyone knows…

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