# General

**URL:** https://discourse.nodered.org/c/general/7.md?page=878

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

**Page:** 879

---

## [Principle system questions](https://discourse.nodered.org/t/principle-system-questions/11977)

<div class="topic-metadata">

**Author:** [@mindthegap](https://discourse.nodered.org/u/mindthegap)\
**Replies:** 4\
**Last updated:** [9 June 2019 11:05 UTC](https://discourse.nodered.org/t/principle-system-questions/11977 "2019-06-09T11:05:40Z")

</div>

I have a project with the following parameters about 20 Arduinos which have a series of switches, sensors, pin pads; Control LEDs (communication via UDP / OSC) Some Windows / PC applications to send and receive individ…

---

## [Many gateways on one network](https://discourse.nodered.org/t/many-gateways-on-one-network/11972)

<div class="topic-metadata">

**Author:** [@sotiriszegiannis](https://discourse.nodered.org/u/sotiriszegiannis)\
**Replies:** 12\
**Last updated:** [9 June 2019 10:59 UTC](https://discourse.nodered.org/t/many-gateways-on-one-network/11972 "2019-06-09T10:59:25Z")

</div>

Hi everyone. I would really appreciate it if anyone know if we can have more than one gateways in the same local network. At the moment if i put a second gw, there doesnt seem to be a way to change the default port 1880 …

---

## [Trouble with Layout and other stuff](https://discourse.nodered.org/t/trouble-with-layout-and-other-stuff/11986)

<div class="topic-metadata">

**Author:** [@MikeInNC](https://discourse.nodered.org/u/MikeInNC)\
**Replies:** 2\
**Last updated:** [8 June 2019 21:47 UTC](https://discourse.nodered.org/t/trouble-with-layout-and-other-stuff/11986 "2019-06-08T21:47:19Z")

</div>

Hi all, I'm having trouble getting all my flows rto show up in the layout. I have two flows but I can't get both to show up in the Layout. Been looking at a tutorial that says to select the proper group on each object…

---

## [Custom logging on RPi docker setup for node-red](https://discourse.nodered.org/t/custom-logging-on-rpi-docker-setup-for-node-red/11982)

<div class="topic-metadata">

**Author:** [@Arm555](https://discourse.nodered.org/u/Arm555)\
**Replies:** 0\
**Last updated:** [8 June 2019 17:26 UTC](https://discourse.nodered.org/t/custom-logging-on-rpi-docker-setup-for-node-red/11982 "2019-06-08T17:26:41Z")

</div>

trying to setup some logging setup that I can see on my phone some how to see what is going on with a flow that didn’t execute properly. What is the best way to do this? The debug nodes are fine but I want to actively v…

---

## [IOT- How to send payload from IOT platform to raspberry pi GPIO](https://discourse.nodered.org/t/iot-how-to-send-payload-from-iot-platform-to-raspberry-pi-gpio/11941)

<div class="topic-metadata">

**Author:** [@Busganda](https://discourse.nodered.org/u/Busganda)\
**Replies:** 4\
**Last updated:** [8 June 2019 16:05 UTC](https://discourse.nodered.org/t/iot-how-to-send-payload-from-iot-platform-to-raspberry-pi-gpio/11941 "2019-06-08T16:05:45Z")

</div>

Hello, how do I send payload from an IOT platform to raspberry pi GPIO? I would like to switch my led from an IOT platform. Which IOT service does this? Thanks.

---

## [Change in MQTT input node?](https://discourse.nodered.org/t/change-in-mqtt-input-node/11978)

<div class="topic-metadata">

**Author:** [@wb666greene](https://discourse.nodered.org/u/wb666greene)\
**Replies:** 1\
**Last updated:** [8 June 2019 14:34 UTC](https://discourse.nodered.org/t/change-in-mqtt-input-node/11978 "2019-06-08T14:34:06Z")

</div>

I recently installed my Ai system at a friends shop. Virgin Linux install. Everything was working fine except the node-red flow that does the Email notifications and dashboard controller to set the operating mode. Tu…

---

## [Something weird with my WAP scanning](https://discourse.nodered.org/t/something-weird-with-my-wap-scanning/11973)

<div class="topic-metadata">

**Author:** [@Trying\_to\_learn](https://discourse.nodered.org/u/Trying_to_learn)\
**Replies:** 0\
**Last updated:** [8 June 2019 10:16 UTC](https://discourse.nodered.org/t/something-weird-with-my-wap-scanning/11973 "2019-06-08T10:16:24Z")

</div>

Ok, this is not really going to be very well formatted, but it is a sort of strange happening. I have a couple of WAPs. I have an arduino connected to a WAP. This WAP is a RPI. When ever a new device connects a req…

---

## [Connecting to philips hue hub](https://discourse.nodered.org/t/connecting-to-philips-hue-hub/11971)

<div class="topic-metadata">

**Author:** [@hif](https://discourse.nodered.org/u/hif)\
**Replies:** 1\
**Last updated:** [8 June 2019 08:53 UTC](https://discourse.nodered.org/t/connecting-to-philips-hue-hub/11971 "2019-06-08T08:53:20Z")

</div>

first of all id like to say HI and im totaly new to all this node red im trying to connect my hue hub to node red and it nothing happens i put in the ip of the hue bridge and press the button like requested nothing see…

---

## [MQTT, message formats (again) stuck](https://discourse.nodered.org/t/mqtt-message-formats-again-stuck/11961)

<div class="topic-metadata">

**Author:** [@Trying\_to\_learn](https://discourse.nodered.org/u/Trying_to_learn)\
**Replies:** 8\
**Last updated:** [8 June 2019 08:51 UTC](https://discourse.nodered.org/t/mqtt-message-formats-again-stuck/11961 "2019-06-08T08:51:03Z")

</div>

This is the flow (cut down) \[{"id":"54dcbdbf.2fe7a4","type":"inject","z":"c56bddee.ca0a18","name":"test","topic":"","payload":"","payloadType":"str","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":520,"y":1810…

---

## [Hitachi now using NR in their IoT platform? This is big!](https://discourse.nodered.org/t/hitachi-now-using-nr-in-their-iot-platform-this-is-big/11927)

<div class="topic-metadata">

**Author:** [@IoTPlay](https://discourse.nodered.org/u/IoTPlay)\
**Replies:** 3\
**Last updated:** [8 June 2019 08:07 UTC](https://discourse.nodered.org/t/hitachi-now-using-nr-in-their-iot-platform-this-is-big/11927 "2019-06-08T08:07:14Z")

</div>

Nick, you mentioned in passing here about ‘our friends over at Hitachi’, then hunted for what you mentioned, and found this announcement, where you are also quoted. Firstly, well done to Hitachi, well done to you Nick! …

---

## [Start learning Nodered](https://discourse.nodered.org/t/start-learning-nodered/11890)

<div class="topic-metadata">

**Author:** [@mustafa](https://discourse.nodered.org/u/mustafa)\
**Replies:** 7\
**Last updated:** [8 June 2019 01:25 UTC](https://discourse.nodered.org/t/start-learning-nodered/11890 "2019-06-08T01:25:28Z")

</div>

Dears I need your advice for how to stat to learn Nodered especially I have never study any programming language before also I have no idea about the programming languages which one the best to use with raspberry pi to …

---

## [Node-Red MQTT AND a Python MQTT script?](https://discourse.nodered.org/t/node-red-mqtt-and-a-python-mqtt-script/11950)

<div class="topic-metadata">

**Author:** [@dclear](https://discourse.nodered.org/u/dclear)\
**Replies:** 5\
**Last updated:** [8 June 2019 00:34 UTC](https://discourse.nodered.org/t/node-red-mqtt-and-a-python-mqtt-script/11950 "2019-06-08T00:34:58Z")

</div>

Does anyone know if it's possible to have Node-Red listening out for MQTT commands on a Raspberry Pi that's ALSO trying to use Mosquitto to PUBLISH MQTT messages? Basically I've got a Raspberry Pi which is happily and s…

---

## [How to include header file node red](https://discourse.nodered.org/t/how-to-include-header-file-node-red/11936)

<div class="topic-metadata">

**Author:** [@tramanah](https://discourse.nodered.org/u/tramanah)\
**Replies:** 3\
**Last updated:** [8 June 2019 00:29 UTC](https://discourse.nodered.org/t/how-to-include-header-file-node-red/11936 "2019-06-08T00:29:36Z")

</div>

good day, I am trying to using c++ code with header file in node red. May I know how to go about it. #include "../arduPi.h" #include "../sim7x00.h" // Pin definition int POWERKEY = 6; int8\_t answer; void setup() { s…

---

## [Substraction 2 msg payload by using topic](https://discourse.nodered.org/t/substraction-2-msg-payload-by-using-topic/10471)

<div class="topic-metadata">

**Author:** [@aabbas](https://discourse.nodered.org/u/aabbas)\
**Replies:** 9\
**Last updated:** [7 June 2019 14:24 UTC](https://discourse.nodered.org/t/substraction-2-msg-payload-by-using-topic/10471 "2019-06-07T14:24:12Z")

</div>

Hi Node community! I need some help in trying to do a subtraction operation between two messages that are msg.payload: Topic like: {“T1”:25,“T2”:22}. I want all time make substraction (T1-T2) even T2 is receiving before…

---

## [Flush serial port (sending AT commands)](https://discourse.nodered.org/t/flush-serial-port-sending-at-commands/11907)

<div class="topic-metadata">

**Author:** [@tramanah](https://discourse.nodered.org/u/tramanah)\
**Replies:** 5\
**Last updated:** [7 June 2019 13:35 UTC](https://discourse.nodered.org/t/flush-serial-port-sending-at-commands/11907 "2019-06-07T13:35:14Z")

</div>

Hi, i am trying sending AT command in gsm modem and check conditions. First, I do send "AT" command and modem replied "OK". Next, I do send "AT+CGPS=1" to switch on the gps but system sending again the "AT". I do underst…

---

## [Topic msg for mathematics equation](https://discourse.nodered.org/t/topic-msg-for-mathematics-equation/11938)

<div class="topic-metadata">

**Author:** [@aabbas](https://discourse.nodered.org/u/aabbas)\
**Replies:** 1\
**Last updated:** [7 June 2019 12:41 UTC](https://discourse.nodered.org/t/topic-msg-for-mathematics-equation/11938 "2019-06-07T12:41:42Z")

</div>

Hi, I am using the msg topic to make number substraction or sum. Here you have the flow that I am using to make my equation but I get NaN all time. Could you please help me. \[{"id":"51e16efc.60bc","type":"inject","z":"…

---

## [Kill youtube live stream](https://discourse.nodered.org/t/kill-youtube-live-stream/11925)

<div class="topic-metadata">

**Author:** [@mshaz](https://discourse.nodered.org/u/mshaz)\
**Replies:** 1\
**Last updated:** [7 June 2019 07:52 UTC](https://discourse.nodered.org/t/kill-youtube-live-stream/11925 "2019-06-07T07:52:29Z")

</div>

Hi, I need help. I triggered youtube live stream and it was working but it doesn't stop streaming with kill command below. Is there other way of doing this? Thank you

---

## [Message handeling..... stuck](https://discourse.nodered.org/t/message-handeling-stuck/11835)

<div class="topic-metadata">

**Author:** [@Trying\_to\_learn](https://discourse.nodered.org/u/Trying_to_learn)\
**Replies:** 21\
**Last updated:** [7 June 2019 05:25 UTC](https://discourse.nodered.org/t/message-handeling-stuck/11835 "2019-06-07T05:25:04Z")

</div>

I've tried. I'm stuck. I am getting this and need to process it. {"topic":"STATUS/WIFIDEVICEID","payload":"{\\"WIFI\_DEVICE\\":\\"GPS\\",\\"IP\_Address\\":\\"192.168.1.4\\"}","qos":0,"retain":false,"time":"2019-6-4 19:51:11","…

---

## [JSONata - $substringBefore](https://discourse.nodered.org/t/jsonata-substringbefore/11920)

<div class="topic-metadata">

**Author:** [@Andrei](https://discourse.nodered.org/u/Andrei)\
**Replies:** 1\
**Last updated:** [6 June 2019 21:07 UTC](https://discourse.nodered.org/t/jsonata-substringbefore/11920 "2019-06-06T21:07:53Z")

</div>

It has been asked in this post how to remove from an array the strings that start with a period character. The first solution proposed is simply brilliant. It uses the array.filter() method, ES6 arrow function and a ter…

---

## [Ideas to remove an entry starting with a period from an array of filenames?](https://discourse.nodered.org/t/ideas-to-remove-an-entry-starting-with-a-period-from-an-array-of-filenames/11854)

<div class="topic-metadata">

**Author:** [@zenofmud](https://discourse.nodered.org/u/zenofmud)\
**Replies:** 9\
**Last updated:** [6 June 2019 19:52 UTC](https://discourse.nodered.org/t/ideas-to-remove-an-entry-starting-with-a-period-from-an-array-of-filenames/11854 "2019-06-06T19:52:09Z")

</div>

I'm using node-red-contrib-fs-ops to get a list of the files in a folder. The names of the files are returned in an array. However it is also returning the hidden files (ones starting with a period) and I don't want them…

---

## [How to get and separate the data from OPC UA](https://discourse.nodered.org/t/how-to-get-and-separate-the-data-from-opc-ua/11903)

<div class="topic-metadata">

**Author:** [@weng](https://discourse.nodered.org/u/weng)\
**Replies:** 2\
**Last updated:** [6 June 2019 12:39 UTC](https://discourse.nodered.org/t/how-to-get-and-separate-the-data-from-opc-ua/11903 "2019-06-06T12:39:48Z")

</div>

I have downloaded "IIoT" on palette and successfully connected to the OPC UA Server. I also recovered the data successfully as the Debug window i could see , but my Node-Id has three groups. How do I get the data of …

---

## [RP Pi input interference / minimal push time of button](https://discourse.nodered.org/t/rp-pi-input-interference-minimal-push-time-of-button/11910)

<div class="topic-metadata">

**Author:** [@RogierQ](https://discourse.nodered.org/u/RogierQ)\
**Replies:** 1\
**Last updated:** [6 June 2019 12:37 UTC](https://discourse.nodered.org/t/rp-pi-input-interference-minimal-push-time-of-button/11910 "2019-06-06T12:37:29Z")

</div>

Hi! I have a challange with a raspberry input pin. Because of some interference the input sometimes jumps up and down. So i tried a 10nF and all other stuff but without succes. So the idea came up to create a check i…

---

## [Connect Node-Red to DFRobot BLE-LINK](https://discourse.nodered.org/t/connect-node-red-to-dfrobot-ble-link/11906)

<div class="topic-metadata">

**Author:** [@monilyn](https://discourse.nodered.org/u/monilyn)\
**Replies:** 1\
**Last updated:** [6 June 2019 11:35 UTC](https://discourse.nodered.org/t/connect-node-red-to-dfrobot-ble-link/11906 "2019-06-06T11:35:30Z")

</div>

Hi, I have created Sketch with Arduino to get data made from DFRobot BLE-LINK(with bluetooth) . Now I need to connect the whole to Node-Red, so I can start to create flows, deploy and get my dashboard. May I ask if an…

---

## [Multiple instances of node-red using PM2?](https://discourse.nodered.org/t/multiple-instances-of-node-red-using-pm2/4888)

<div class="topic-metadata">

**Author:** [@vtgav](https://discourse.nodered.org/u/vtgav)\
**Replies:** 3\
**Last updated:** [6 June 2019 07:14 UTC](https://discourse.nodered.org/t/multiple-instances-of-node-red-using-pm2/4888 "2019-06-06T07:14:16Z")

</div>

Greetings, I run node-red with pm2 using :- pm2 start node-red which works fine. I can manually start a second instance with its own settings file from the command line :- node-red -s node-red2/settings.js -u node-…

---

## [MQTT configuration from file or env. variable](https://discourse.nodered.org/t/mqtt-configuration-from-file-or-env-variable/11617)

<div class="topic-metadata">

**Author:** [@Chris24918](https://discourse.nodered.org/u/Chris24918)\
**Replies:** 17\
**Last updated:** [29 May 2019 15:13 UTC](https://discourse.nodered.org/t/mqtt-configuration-from-file-or-env-variable/11617 "2019-05-29T15:13:35Z")

</div>

Hello, I’m trying to figure out a way to configure my MQTT node’s Client ID , UserName, and Password, outside of the flow. My web portal assigns all the above and they are 32 to 64 characters long. The Client Id is us…

---

## [WOL Node red not working(solved)](https://discourse.nodered.org/t/wol-node-red-not-working-solved/11882)

<div class="topic-metadata">

**Author:** [@sucram](https://discourse.nodered.org/u/sucram)\
**Replies:** 3\
**Last updated:** [5 June 2019 20:58 UTC](https://discourse.nodered.org/t/wol-node-red-not-working-solved/11882 "2019-06-05T20:58:48Z")

</div>

I have a node red flow to wake up my iMac but can't get it working. I hope someone can point me in the right direction ? I have looked at post: to try understand a little more , have entered mac address and broadca…

---

## [Strange URL format via Template node // = &#x2F;&#x2F;](https://discourse.nodered.org/t/strange-url-format-via-template-node-x2f-x2f/11881)

<div class="topic-metadata">

**Author:** [@nodecentral](https://discourse.nodered.org/u/nodecentral)\
**Replies:** 4\
**Last updated:** [5 June 2019 19:52 UTC](https://discourse.nodered.org/t/strange-url-format-via-template-node-x2f-x2f/11881 "2019-06-05T19:52:39Z")

</div>

Hi I’m trying to build a dynamic URL from a few payloads, but for some reason the resulting first part of the address looks encoded, yet the template output should be plain text? Here’s the flow which has the PollyURL …

---

## [Node-Red Guidance/Consultancy needed - funded work](https://discourse.nodered.org/t/node-red-guidance-consultancy-needed-funded-work/11878)

<div class="topic-metadata">

**Author:** [@tony-shannon](https://discourse.nodered.org/u/tony-shannon)\
**Replies:** 2\
**Last updated:** [5 June 2019 19:43 UTC](https://discourse.nodered.org/t/node-red-guidance-consultancy-needed-funded-work/11878 "2019-06-05T19:43:15Z")

</div>

Dear Node-Red community, I'm writing looking for some guidance/consultancy/help on how to make the best use of NodeRed , as we begin to explore its potential in the open source healthcare field where we work. If anyone…

---

## [Multiple Content Stores](https://discourse.nodered.org/t/multiple-content-stores/11879)

<div class="topic-metadata">

**Author:** [@Bra1nK](https://discourse.nodered.org/u/Bra1nK)\
**Replies:** 3\
**Last updated:** [5 June 2019 18:15 UTC](https://discourse.nodered.org/t/multiple-content-stores/11879 "2019-06-05T18:15:29Z")

</div>

I've been playing with the recent context storage enhancements after updating to version 0.20.05 and don't get a choice in the ui for which store to use as stated in the docs Using Context in a flow below are the relevan…

---

## [Node-red stopped working?](https://discourse.nodered.org/t/node-red-stopped-working/11741)

<div class="topic-metadata">

**Author:** [@myozone](https://discourse.nodered.org/u/myozone)\
**Replies:** 85\
**Last updated:** [5 June 2019 15:40 UTC](https://discourse.nodered.org/t/node-red-stopped-working/11741 "2019-06-05T15:40:38Z")

</div>

Hello, I've had Node-red running happily running for a long time but suddenly it's stopped. It appears to be running with over 100% usage report from TOP but no GUI or anything working - any ideas please? top - 09:41:05…

[Previous page](https://discourse.nodered.org/c/general/7.md?page=877)

[Next page](https://discourse.nodered.org/c/general/7.md?page=879)