# How to dim/brighten RGB strip lights over time

**URL:** <https://discourse.nodered.org/t/how-to-dim-brighten-rgb-strip-lights-over-time/25137>\
**Category:** General\
**Created:** [19 April 2020 15:17 UTC](https://discourse.nodered.org/t/how-to-dim-brighten-rgb-strip-lights-over-time/25137 "2020-04-19T15:17:20Z")\
**Posts on this page:** 8\
**Page:** 1

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**Author:** ![phreaq](https://avatars.discourse-cdn.com/v4/letter/p/b9bd4f/32.png) [@phreaq](https://discourse.nodered.org/u/phreaq)\
**Post date:** [19 April 2020 15:17 UTC](https://discourse.nodered.org/t/how-to-dim-brighten-rgb-strip-lights-over-time/25137/1 "2020-04-19T15:17:21Z")

</div>

Hi folks,

I have a few RGB light strips hooked up via a wifi controller, and I am controlling them thru node-red/ha.

Is there a routine/method, that I can have the lights slow dim/brighten over time?

For example, if i have a flow that will dim the light strip to 20% brightness over 5 minutes, it would find the current brightness value, find the delta difference, and then gradually decrease that difference over the 5 minute time frame.

I suspect several components would be needed to do this, which would fire an event off to the wifi controllers ever x seconds or so.

has anyone done this yet, or have any pointers?

TIA

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<div class="post-metadata">

**Author:** ![bakman2](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/bakman2/32/6207_2.png) [@bakman2](https://discourse.nodered.org/u/bakman2)\
**Post date:** [19 April 2020 16:08 UTC](https://discourse.nodered.org/t/how-to-dim-brighten-rgb-strip-lights-over-time/25137/2 "2020-04-19T16:08:13Z")

</div>

This is a very broad question, with a very broad answer: node-red can do it.

There are many ways to do this, with home assistant I don't know because I don't use that, but I can imagine that you can control your wifi controller directly from NR or from HA.

But there is not a "component" that will do this for you because of the many variables that apply.

Questions:

- Do you "just" want to dim the strip to 20% brightness over 5 minutes or
- Do you want to sync it to something like sunrise
- Do you want it to happen on a specific time or via a certain trigger ?

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<div class="post-metadata">

**Author:** ![phreaq](https://avatars.discourse-cdn.com/v4/letter/p/b9bd4f/32.png) [@phreaq](https://discourse.nodered.org/u/phreaq)\
**Post date:** [19 April 2020 16:09 UTC](https://discourse.nodered.org/t/how-to-dim-brighten-rgb-strip-lights-over-time/25137/3 "2020-04-19T16:09:52Z")

</div>

bakman2, thanks for the reply.

In this case, I "just" want to dim the strip to 20% brightness over 5 minutes. Once that's figured out, I can trigger it with various other items in my other nodes.

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<div class="post-metadata">

**Author:** ![bakman2](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/bakman2/32/6207_2.png) [@bakman2](https://discourse.nodered.org/u/bakman2)\
**Post date:** [19 April 2020 16:33 UTC](https://discourse.nodered.org/t/how-to-dim-brighten-rgb-strip-lights-over-time/25137/4 "2020-04-19T16:33:08Z")

</div>

Simple example:

5 minutes is 300 seconds, send value+1 every 15 seconds, 20 times = 5 minutes and the 20% brightness you should map yourself somewhere towards the striplight.

```auto
[{"id":"b1e6a54.d960d58","type":"function","z":"bb6546dd.319b98","name":"","func":"let d = 1\n\ndimmer()\nvar timer = setInterval(dimmer, 15000);\n\nfunction dimmer() {\n \n \n if(d>20){\n stopDimmer() \n }\n else{\n node.send({payload:{dimmer:d}})\n d++\n }\n}\n\nfunction stopDimmer() {\n clearInterval(timer);\n}","outputs":1,"noerr":0,"x":314,"y":288,"wires":[["5fa67a01.f04a2c"]]},{"id":"1a492d63.f5cd6b","type":"inject","z":"bb6546dd.319b98","name":"","topic":"","payload":"","payloadType":"date","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":180,"y":288,"wires":[["b1e6a54.d960d58"]]},{"id":"5fa67a01.f04a2c","type":"debug","z":"bb6546dd.319b98","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"false","x":454,"y":288,"wires":[]}]

```

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<div class="post-metadata">

**Author:** ![cflurin](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/cflurin/32/29_2.png) [@cflurin](https://discourse.nodered.org/u/cflurin)\
**Post date:** [19 April 2020 16:52 UTC](https://discourse.nodered.org/t/how-to-dim-brighten-rgb-strip-lights-over-time/25137/5 "2020-04-19T16:52:03Z")

</div>

Have a look at the dsm wiki

> **[cflurin/node-red-contrib-dsm](https://github.com/cflurin/node-red-contrib-dsm/wiki/Fade-in--out)**
>
> A dynamic state machine node based on the Finite state machine. - cflurin/node-red-contrib-dsm

or

> **[cflurin/node-red-contrib-dsm](https://github.com/cflurin/node-red-contrib-dsm/wiki/Fading)**
>
> A dynamic state machine node based on the Finite state machine. - cflurin/node-red-contrib-dsm

---

<div class="post-metadata">

**Author:** ![phreaq](https://avatars.discourse-cdn.com/v4/letter/p/b9bd4f/32.png) [@phreaq](https://discourse.nodered.org/u/phreaq)\
**Post date:** [20 April 2020 14:58 UTC](https://discourse.nodered.org/t/how-to-dim-brighten-rgb-strip-lights-over-time/25137/6 "2020-04-20T14:58:20Z")

</div>

bakman2, that's exactly what I needed.

I made a few tweaks, as needed, and works perfect, thanks!

---

<div class="post-metadata">

**Author:** ![phreaq](https://avatars.discourse-cdn.com/v4/letter/p/b9bd4f/32.png) [@phreaq](https://discourse.nodered.org/u/phreaq)\
**Post date:** [21 April 2020 13:29 UTC](https://discourse.nodered.org/t/how-to-dim-brighten-rgb-strip-lights-over-time/25137/7 "2020-04-21T13:29:52Z")

</div>

In case anyone stumbles on this in the future, here's a bit more coding based around bakman2's original code.

I added in a few variables, and have a few checks and balances going on (it will dim or brighten accordingly).

this is my first chunk of code done in js, so it may not be to best practices...

```auto
[{"id":"3ecc6bc2.1b93b4","type":"inject","z":"25593659.aa9afa","name":"","topic":"","payload":"","payloadType":"date","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":460,"y":1840,"wires":[["47536eab.c10f9"]]},{"id":"47536eab.c10f9","type":"api-current-state","z":"25593659.aa9afa","name":"Kitchen Upper Status","server":"1e3a8fe9.e93cf","version":1,"outputs":1,"halt_if":"","halt_if_type":"str","halt_if_compare":"is","override_topic":true,"entity_id":"light.kitchen_upper","state_type":"str","state_location":"payload","override_payload":"msg","entity_location":"data","override_data":"msg","blockInputOverrides":false,"x":680,"y":1840,"wires":[["3b178f5.58d107"]]},{"id":"3b178f5.58d107","type":"function","z":"25593659.aa9afa","name":"switch to 80% - 5 seconds","func":"var Desired_Brightness_Pct = 80 //key in desired percent value (0-100)\nvar Desired_Time = 5 //transition time in seconds\n\n//do not edit below this line\n\nvar CurrBrightness_Pct = 0\nvar TimerValue = 1\nvar LightStatus = (msg.data.state)\n\nif (LightStatus == \"on\") \n {\n CurrBrightness_Pct = (((msg.data.attributes.brightness)/255*100).toFixed(0))\n }\n else\n {\n CurrBrightness_Pct = 0\n }\n\nvar Delta = (Desired_Brightness_Pct - CurrBrightness_Pct)\n\nif(Delta < 0)\n {\n TimerValue = ((Desired_Time/(Delta)*-1)*1000) \n } \n else\n {\n TimerValue = ((Desired_Time/Delta)*1000)\n }\nlet CBP = CurrBrightness_Pct\n\ndimmer()\nvar timer = setInterval(dimmer, TimerValue);\n\nfunction dimmer() \n{\n if(Delta > 0)\n {\n if(CBP >= Desired_Brightness_Pct)\n {\n node.send({payload:{dimmer:Desired_Brightness_Pct}}) \n stopDimmer() \n }\n else\n {\n node.send({payload:{dimmer:CBP}})\n CBP++\n }\n }\n else\n {\n if(CBP <= Desired_Brightness_Pct)\n {\n node.send({payload:{dimmer:Desired_Brightness_Pct}}) \n stopDimmer() \n }\n else\n {\n node.send({payload:{dimmer:CBP}})\n CBP--\n }\n }\n \n}\n\nfunction stopDimmer() {\n clearInterval(timer);\n}\n\n\n\n","outputs":1,"noerr":0,"x":1050,"y":1860,"wires":[["6aba205d.456ec"]]},{"id":"6aba205d.456ec","type":"api-call-service","z":"25593659.aa9afa","name":"Kitchen Upper (128, 20, 0)","server":"1e3a8fe9.e93cf","version":1,"debugenabled":false,"service_domain":"light","service":"turn_on","entityId":"light.kitchen_upper","data":"{\"rgb_color\":[128,20,0],\"brightness_pct\":\"{{payload.dimmer}}\"}","dataType":"json","mergecontext":"","output_location":"","output_location_type":"none","mustacheAltTags":false,"x":1500,"y":1880,"wires":[[]]},{"id":"84fc14af.28e508","type":"inject","z":"25593659.aa9afa","name":"","topic":"","payload":"","payloadType":"date","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":460,"y":1980,"wires":[["5bbce65f.5be798"]]},{"id":"5bbce65f.5be798","type":"api-current-state","z":"25593659.aa9afa","name":"Kitchen Upper Status","server":"1e3a8fe9.e93cf","version":1,"outputs":1,"halt_if":"","halt_if_type":"str","halt_if_compare":"is","override_topic":true,"entity_id":"light.kitchen_upper","state_type":"str","state_location":"payload","override_payload":"msg","entity_location":"data","override_data":"msg","blockInputOverrides":false,"x":680,"y":1980,"wires":[["a75eb2f0.9500b"]]},{"id":"a75eb2f0.9500b","type":"function","z":"25593659.aa9afa","name":"switch to 20% - 5 seconds","func":"var Desired_Brightness_Pct = 20 //key in desired percent value (0-100)\nvar Desired_Time = 5 //transition time in seconds\n\n//do not edit below this line\n\nvar CurrBrightness_Pct = 0\nvar TimerValue = 1\nvar LightStatus = (msg.data.state)\n\nif (LightStatus == \"on\") \n {\n CurrBrightness_Pct = (((msg.data.attributes.brightness)/255*100).toFixed(0))\n }\n else\n {\n CurrBrightness_Pct = 0\n }\n\nvar Delta = (Desired_Brightness_Pct - CurrBrightness_Pct)\n\nif(Delta < 0)\n {\n TimerValue = ((Desired_Time/(Delta)*-1)*1000) \n } \n else\n {\n TimerValue = ((Desired_Time/Delta)*1000)\n }\nlet CBP = CurrBrightness_Pct\n\ndimmer()\nvar timer = setInterval(dimmer, TimerValue);\n\nfunction dimmer() \n{\n if(Delta > 0)\n {\n if(CBP >= Desired_Brightness_Pct)\n {\n node.send({payload:{dimmer:Desired_Brightness_Pct}}) \n stopDimmer() \n }\n else\n {\n node.send({payload:{dimmer:CBP}})\n CBP++\n }\n }\n else\n {\n if(CBP <= Desired_Brightness_Pct)\n {\n node.send({payload:{dimmer:Desired_Brightness_Pct}}) \n stopDimmer() \n }\n else\n {\n node.send({payload:{dimmer:CBP}})\n CBP--\n }\n }\n \n}\n\nfunction stopDimmer() {\n clearInterval(timer);\n}\n\n\n\n","outputs":1,"noerr":0,"x":1050,"y":2000,"wires":[["98f77cc8.91b4f"]]},{"id":"98f77cc8.91b4f","type":"api-call-service","z":"25593659.aa9afa","name":"Kitchen Upper (128, 20, 0)","server":"1e3a8fe9.e93cf","version":1,"debugenabled":false,"service_domain":"light","service":"turn_on","entityId":"light.kitchen_upper","data":"{\"rgb_color\":[128,20,0],\"brightness_pct\":\"{{payload.dimmer}}\"}","dataType":"json","mergecontext":"","output_location":"","output_location_type":"none","mustacheAltTags":false,"x":1500,"y":2020,"wires":[[]]},{"id":"27fa326b.71eb2e","type":"inject","z":"25593659.aa9afa","name":"","topic":"","payload":"","payloadType":"date","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":460,"y":2140,"wires":[["c294f4de.9bb518"]]},{"id":"c294f4de.9bb518","type":"api-current-state","z":"25593659.aa9afa","name":"Kitchen Upper Status","server":"1e3a8fe9.e93cf","version":1,"outputs":1,"halt_if":"","halt_if_type":"str","halt_if_compare":"is","override_topic":true,"entity_id":"light.kitchen_upper","state_type":"str","state_location":"payload","override_payload":"msg","entity_location":"data","override_data":"msg","blockInputOverrides":false,"x":680,"y":2140,"wires":[["bcf31de.373c9e"]]},{"id":"bcf31de.373c9e","type":"function","z":"25593659.aa9afa","name":"switch to 0% - 5 seconds","func":"var Desired_Brightness_Pct = 0 //key in desired percent value (0-100)\nvar Desired_Time = 5 //transition time in seconds\n\n//do not edit below this line\n\nvar CurrBrightness_Pct = 0\nvar TimerValue = 1\nvar LightStatus = (msg.data.state)\n\nif (LightStatus == \"on\") \n {\n CurrBrightness_Pct = (((msg.data.attributes.brightness)/255*100).toFixed(0))\n }\n else\n {\n CurrBrightness_Pct = 0\n }\n\nvar Delta = (Desired_Brightness_Pct - CurrBrightness_Pct)\n\nif(Delta < 0)\n {\n TimerValue = ((Desired_Time/(Delta)*-1)*1000) \n } \n else\n {\n TimerValue = ((Desired_Time/Delta)*1000)\n }\nlet CBP = CurrBrightness_Pct\n\ndimmer()\nvar timer = setInterval(dimmer, TimerValue);\n\nfunction dimmer() \n{\n if(Delta > 0)\n {\n if(CBP >= Desired_Brightness_Pct)\n {\n node.send({payload:{dimmer:Desired_Brightness_Pct}}) \n stopDimmer() \n }\n else\n {\n node.send({payload:{dimmer:CBP}})\n CBP++\n }\n }\n else\n {\n if(CBP <= Desired_Brightness_Pct)\n {\n node.send({payload:{dimmer:Desired_Brightness_Pct}}) \n stopDimmer() \n }\n else\n {\n node.send({payload:{dimmer:CBP}})\n CBP--\n }\n }\n \n}\n\nfunction stopDimmer() {\n clearInterval(timer);\n}\n\n\n\n","outputs":1,"noerr":0,"x":1050,"y":2160,"wires":[["f7e68c7d.82751"]]},{"id":"f7e68c7d.82751","type":"api-call-service","z":"25593659.aa9afa","name":"Kitchen Upper (128, 20, 0)","server":"1e3a8fe9.e93cf","version":1,"debugenabled":false,"service_domain":"light","service":"turn_on","entityId":"light.kitchen_upper","data":"{\"rgb_color\":[128,20,0],\"brightness_pct\":\"{{payload.dimmer}}\"}","dataType":"json","mergecontext":"","output_location":"","output_location_type":"none","mustacheAltTags":false,"x":1500,"y":2180,"wires":[[]]},{"id":"1e3a8fe9.e93cf","type":"server","z":"","name":"Home Assistant","legacy":false,"addon":true,"rejectUnauthorizedCerts":true,"ha_boolean":"y|yes|true|on|home|open","connectionDelay":true,"cacheJson":true}]

```

---

<div class="post-metadata">

**Author:** ![system](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/1X/d073cd938eafa2e558d7c2cd59003b3ef4963033.png) [@system](https://discourse.nodered.org/u/system)\
**Post date:** [20 June 2020 13:29 UTC](https://discourse.nodered.org/t/how-to-dim-brighten-rgb-strip-lights-over-time/25137/8 "2020-06-20T13:29:57Z")

</div>

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