Parallel LED strips with one NodeMCU

I read Issue 409 and understand the wiring requirements but what is the maximum number of parallel LED strips that you can drive from one NodeMCU?

As far as the data circuit is concerned, can I run eight parallel 5 volt WS2812b strips from one NodeMCU?

Four of the strips would have 44 LEDs and four strips would have 53 LEDs. I could make each strip the same if need be. I always use a 74HCT245N as a level shifter and the total length of the wire from D4 to connect all eight strips would be one metre. I’m currently using WLED version 0.9.1

Other options are use more than one NodeMCU and sync them with WLED or setup one 388 LED strip with the appropriate wiring and power injection. My project is to light the inside of a gazebo with eight LED strips radiating from the centre of the roof.

I prefer to use eight parallel strips rather than one strip of 388 LEDs but I need more info. Canyou help me?

Thanks,
Drew.

Hi!
No guarantees, but when using a levelshifter, 8 strips should work just fine in parallel! As these LEDs are daisy chained, they don’t have to have the same length, don’t worry. I’d agree with you that wiring them up in parallel is probably the best fit for your use case :slight_smile:

Excellent. Better than I expected. Thank you Aircoookie for your quick response and congratulations on WLED.
Drew.

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Hi
What would be the maximum number of outputs on an ESP32 ?
What would be the preferred pins for these outputs ? Or even better all of them ! ?

Thanks

Harald

Hi!
There will be 8 outputs possible with the ESP32 RMT hardware! Pins can be choosen freely as long as they aren’t reserved for internal purpuses (flash memory interface) :slight_smile:

Hi Aircookie

Thanks for this very quick response !
I was hoping for more output pins, what is the limiting factor ?

More than 8 pins per mcu, each of them being able to potentially run 2048 LED is not enough? :joy:
The limiting factor here is the RMT hardware for effortless driving of the LEDs, which has 8 channels. It is possible to go further using software bitbanging, but that can lead to instabilities. Now I’m curious, what is your use case for so many pins? Assuming addressable LEDs, if you want to interface with “dumb” PWM LEDs, 16 channels will be possible.

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What is the limit if all connected addressable LED strips are always in sync? With level shifters, the limit then becomes far greater than 8, correct?

What if there were attributes associated with each effect that included the CPU load, static memory load, dynamic memory load, saved memory load, and/or file system load?

WLED then could allow more LED strip pins, presenting only those effects compatible with the current number of defined LED strips, in terms of total memory consumption (static, dynamic, stored / file system) and CPU usage.

That might be WLED 2.0.0, but we can dream can’t we? :heart_eyes:

WLED should be able to run all effects with the maximum allowable LED count, having some that don’t run if you are over a specific amount of resources would be confusing (albeit this is already the case right now, some effects that need extra memory, e.g. Colortwinkles, will fallback to Solid color if they can’t allocate the memory).
You are correct, with parallel output (all strips showing the same) the amount of LEDs possible is theoretically unlimited! All I’m saying is that 8 is likely to be the limit of individually addressable output pins on the ESP32, potentially allowing for 16.000 individual LEDs (if we are able to add 2000 per pin)

WLED 2.0.0 might run on the quad core ESP64 and be able to control a full 4K Ultra HD display made of Neopixels :sweat_smile: (actually that’d be 8 million LEDs. And a power usage of 2 megawatts on full white :stuck_out_tongue: )

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@Aircoookie I really like how you look to the future with WLED. But don’t sell other people’s hardware advances short. I’m sure by then, it will be 16K 360 degree SuperHD displays controlled by WLED - you know, like a planetarium, but in your living room!

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