# Neo-pixel LED, heart beat. Help

**URL:** <https://discourse.nodered.org/t/neo-pixel-led-heart-beat-help/97990>\
**Category:** General\
**Created:** [6 July 2025 05:45 UTC](https://discourse.nodered.org/t/neo-pixel-led-heart-beat-help/97990 "2025-07-06T05:45:35Z")\
**Posts on this page:** 10\
**Page:** 1

<div class="post-metadata">

**Author:** ![Trying\_to\_learn](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/trying_to_learn/32/28400_2.png) [@Trying\_to\_learn](https://discourse.nodered.org/u/Trying_to_learn)\
**Post date:** [6 July 2025 05:45 UTC](https://discourse.nodered.org/t/neo-pixel-led-heart-beat-help/97990/1 "2025-07-06T05:45:35Z")

</div>

Folks,

I have a Neo-Pixel LED and want it to blink like a heart beat.

Just wondering if anyone has any ideas on how to do it.

---

<div class="post-metadata">

**Author:** ![Trying\_to\_learn](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/trying_to_learn/32/28400_2.png) [@Trying\_to\_learn](https://discourse.nodered.org/u/Trying_to_learn)\
**Post date:** [6 July 2025 06:00 UTC](https://discourse.nodered.org/t/neo-pixel-led-heart-beat-help/97990/2 "2025-07-06T06:00:56Z")

</div>

This is one idea I made up just now messing around.

## This was posted with `flows` but was problematic in rendering/showing the flow.

```auto
[{"id":"4d9e128f61b30b9a","type":"trigger","z":"a1911aa3.c45be8","name":"","op1":"40","op2":"0","op1type":"num","op2type":"num","duration":"250","extend":false,"overrideDelay":false,"units":"ms","reset":"","bytopic":"all","topic":"topic","outputs":2,"x":750,"y":5330,"wires":[["7a69456b898157aa"],["f2ea8ebf91675d97","7a69456b898157aa"]]},{"id":"7d52e8e1113688cd","type":"trigger","z":"a1911aa3.c45be8","name":"","op1":"20","op2":"0","op1type":"num","op2type":"num","duration":"250","extend":false,"overrideDelay":false,"units":"ms","reset":"","bytopic":"all","topic":"topic","outputs":2,"x":970,"y":5380,"wires":[["7a69456b898157aa"],["7a69456b898157aa","ef16a26c16c1e3c2"]]},{"id":"49b7e79d69b3f6ee","type":"inject","z":"a1911aa3.c45be8","name":"Start","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"","payloadType":"date","x":570,"y":5390,"wires":[["4d9e128f61b30b9a"]]},{"id":"7a69456b898157aa","type":"template","z":"a1911aa3.c45be8","name":"","field":"payload","fieldType":"msg","format":"handlebars","syntax":"mustache","template":"rgb,3,0,{{payload}},0","output":"str","x":1130,"y":5330,"wires":[["cd95830a0d79ecd2","e007d147d4be7647"]]},{"id":"f2ea8ebf91675d97","type":"delay","z":"a1911aa3.c45be8","name":"","pauseType":"delay","timeout":"250","timeoutUnits":"milliseconds","rate":"1","nbRateUnits":"1","rateUnits":"second","randomFirst":"1","randomLast":"5","randomUnits":"seconds","drop":false,"allowrate":false,"outputs":1,"x":760,"y":5380,"wires":[["7d52e8e1113688cd"]]},{"id":"22333e36399b9c35","type":"inject","z":"a1911aa3.c45be8","name":"Stop","repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"CONTROL","payload":"STOP","payloadType":"str","x":570,"y":5250,"wires":[["1048afc94a871bd0"]]},{"id":"14b8f1d26a67e16e","type":"inject","z":"a1911aa3.c45be8","name":"Go","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":"1","topic":"CONTROL","payload":"GO","payloadType":"str","x":570,"y":5290,"wires":[["1048afc94a871bd0"]]},{"id":"1048afc94a871bd0","type":"gate","z":"a1911aa3.c45be8","name":"","controlTopic":"CONTROL","defaultState":"open","openCmd":"GO","closeCmd":"STOP","toggleCmd":"toggle","defaultCmd":"default","persist":false,"x":570,"y":5330,"wires":[["4d9e128f61b30b9a"]]},{"id":"ef16a26c16c1e3c2","type":"delay","z":"a1911aa3.c45be8","name":"","pauseType":"delay","timeout":"5","timeoutUnits":"seconds","rate":"1","nbRateUnits":"1","rateUnits":"second","randomFirst":"1","randomLast":"5","randomUnits":"seconds","drop":false,"allowrate":false,"outputs":1,"x":1105,"y":5380,"wires":[["1048afc94a871bd0"]],"l":false}]

```

---

<div class="post-metadata">

**Author:** ![Paul-Reed](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/paul-reed/32/66906_2.png) [@Paul-Reed](https://discourse.nodered.org/u/Paul-Reed)\
**Post date:** [6 July 2025 08:22 UTC](https://discourse.nodered.org/t/neo-pixel-led-heart-beat-help/97990/3 "2025-07-06T08:22:30Z")

</div>

I'm not seeing anything in your flow visual, although it appears to be formatted correctly...

---

<div class="post-metadata">

**Author:** ![Trying\_to\_learn](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/trying_to_learn/32/28400_2.png) [@Trying\_to\_learn](https://discourse.nodered.org/u/Trying_to_learn)\
**Post date:** [6 July 2025 08:24 UTC](https://discourse.nodered.org/t/neo-pixel-led-heart-beat-help/97990/4 "2025-07-06T08:24:37Z")

</div>

Yeah, sorry I didn't include a `debug` node.

I was wanting to get the _timing_ right so it _beats_ nicely.

Do you think the basics of how I did it good?

---

<div class="post-metadata">

**Author:** ![Paul-Reed](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/paul-reed/32/66906_2.png) [@Paul-Reed](https://discourse.nodered.org/u/Paul-Reed)\
**Post date:** [6 July 2025 08:26 UTC](https://discourse.nodered.org/t/neo-pixel-led-heart-beat-help/97990/5 "2025-07-06T08:26:32Z")

</div>

> [@Trying\_to\_learn](#):
>
> Do you think the basics of how I did it good?

> [@Paul-Reed](#):
>
> I'm not seeing anything in your flow visual,

It's completely blank (as in nothing) and yes I've tried scrolling & zooming.

 ![Screenshot_20250706-102726](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/a/e/ae9c86d7e4387b9fca4532a95716541bfe1e086a.png)

---

<div class="post-metadata">

**Author:** ![Trying\_to\_learn](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/trying_to_learn/32/28400_2.png) [@Trying\_to\_learn](https://discourse.nodered.org/u/Trying_to_learn)\
**Post date:** [6 July 2025 08:29 UTC](https://discourse.nodered.org/t/neo-pixel-led-heart-beat-help/97990/6 "2025-07-06T08:29:08Z")

</div>

The code is there, but _hidden_ somewhere on the left halfway down.

I probably didn't need to use that feature, but thought I'd try it.

 ![Screenshot from 2025-07-06 18-28-47](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/c/3/c33dcb07edfed4838964126fe6158ba65e9e6bea.png)

---

<div class="post-metadata">

**Author:** ![Colin](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/colin/32/17040_2.png) [@Colin](https://discourse.nodered.org/u/Colin)\
**Post date:** [6 July 2025 09:10 UTC](https://discourse.nodered.org/t/neo-pixel-led-heart-beat-help/97990/7 "2025-07-06T09:10:15Z")

</div>

If you Zoom right out and then scroll halfway down it becomes visible. I have posted a comment in [the original post](https://discourse.nodered.org/t/sharing-flows-on-the-forum-just-get-prettier/97957/27) suggesting that the flow may need to be normalised before viewing.

---

<div class="post-metadata">

**Author:** ![knolleary](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/knolleary/32/3_2.png) [@knolleary](https://discourse.nodered.org/u/knolleary)\
**Post date:** [6 July 2025 09:12 UTC](https://discourse.nodered.org/t/neo-pixel-led-heart-beat-help/97990/8 "2025-07-06T09:12:30Z")

</div>

If it isn't working, then just remove the `flows` word so it doesn't try to render it - and add a comment to the original post about the flow viewer so we can track flows that aren't rendering properly.

---

<div class="post-metadata">

**Author:** ![Trying\_to\_learn](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/trying_to_learn/32/28400_2.png) [@Trying\_to\_learn](https://discourse.nodered.org/u/Trying_to_learn)\
**Post date:** [6 July 2025 09:20 UTC](https://discourse.nodered.org/t/neo-pixel-led-heart-beat-help/97990/9 "2025-07-06T09:20:04Z")

</div>

(from my position)

It works though I admit what I posted was/IS rather small so is hard to see/find.  
Which could be part of the problem.

As I said, if I zoom OUT, go to the left and about halfway down: I see it ok.

The last part.... Ok. Shall do.  
(Done.)

---

<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:** [4 October 2025 09:20 UTC](https://discourse.nodered.org/t/neo-pixel-led-heart-beat-help/97990/10 "2025-10-04T09:20:36Z")

</div>

This topic was automatically closed 90 days after the last reply. New replies are no longer allowed.