How does the Pro expander work?

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Suppose I have multiple LED strands of various lengths. If I hook them up to the expander. Can it be setup such that when the strands are powered and lit, it is as if they are one continuous data line?

Meaning that after the last pixel in strand 1 port one lights up, the first led on for the strand on Port 2 starts to light up..as if I wired the strand on Port 2 directly to the first strand and passed data down the direction of travel

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Actually that’s how it works in the default config! For both the pro expander and the other one. You tell the expander how many pixels on each channel and it continues sequential index numbering.

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Are there any 3D cases for the Extended Pro? It seems there are are only 4 ports on it with 2 channels each.

I have a need for 5 strands to be connected. What’s the difference between a port and a channel? I have an indeterminate amount of pixels installed as permanent lighting on the exterior of my house. KT-N12RGB are the bulbs that were installed. I’d like a bit more customization with Pixel blaze than what I get with this controller, specifically for accent lightning.

Do we think this strand can be driven by the pixelblaze with the extender?

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if that helps, I used a plastic box for mine: Marc's Blog: electronics - House Lights with Pixelblaze on ESP32 monitored with Raspberry Pi

Each expander board has 8 outputs, but you can give an ID to the board and have multiple expander boards on the same “bus”
That said, don’t get too excited, the wire speed of 2Mbit/s only gives you about twice the total pixel x fps speed than no output board, so it’s really only useful for wiring reasons, not for running many more LEDs at high speed.
By many I mean that with 4000 pixels, you will be limited to around 20fps even with the expander board.

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Holy cow haha, so many LEDs your house looks like what I would imagine the world looks like as NEO is walking through the Matrix hahaha. So rad.

Yeah I don’t think I’ll have more than 1000 LEDs conservatively if I get the last rack installed, I’ll have maybe 800? Maybe closer to 600.

But similar to your setup, it’s mostly the wiring issue and less speed I’m dealing with. The controller this company shipped with “works” but is limited in what I’ve seen nicer controllers do.

Specifically, the ports on this on seem only have a single channel, and I’ll eventually need another set of ports on it. Hence my looking at pixelblaze.

So it sounds like I can connect in theory two stands of LEDs to a given port and assign an ID to each channel and then I can profit.

Can someone help me understand the difference between the 5V and the 12V DC to DC converter? It looks like it can power a pixelblaze controller also if I’m reading this correctly..

Thanks so much for the details, sick work on the house haha

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The expander has 8 configurable data/clock channels. These are defined in settings to be different LED types data or a clock signal, or disabled.

The expander has 4 “ports” made up of 2 channels each, and each protected with its own fuse. Each port is a 4 wire pluggable screw terminal that provides power and 2 data (or data + clock).

Exactly.

Honestly I don’t know for sure. If it’s something that runs on the WS2812 data protocol, which is most common, then yes. I did find that a similar model “KT-12RGB-12” does run off of the ws2812 protocol, but can’t find that exact model.

The other thing to keep in mind is LED voltage.

The pro expander as a 12V and 5V version. Basically, 5V needs to come from somewhere to power the electronics on the expander and the PB. The 12V model has a DC buck converter included. No 24V option yet, but could be modified to work with 24V by adding on a DC converter to drop 24V to 5V.

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Okay so the PS, on the system which there are two are the 12V MeanWell LRS-200-12 and LRS-100-12. I know each bulb is .6V.

If I’m powering the strand via the PSUs, I don’t think I need to worry about carrying voltage through the channel buses, only ground and data. Would it be recommended to get the 12V DC-DC or 5V expander?

I appreciate all the replies! Thank you!

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Yeah, you’d wand the 12V expander just to simplify things, it will provide 5V for PB.

The main benefit of the pro expander is doing power through it, where you get the fuse protection and the pluggable terminals. It also can drop 12V down to 5 with an included mini buck converter.

If you are doing power yourself then you can get away with the non-pro output expander, and toss in a Mini Buck for 5V. From a data/pixel perspective its the same. Wiring is a little tighter since it’s designed for small size.

I’d recommend fuses though, you don’t want 200W going in to a short :fire:

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First, I have to say I got the pro expander because it looked nice and convenient, but I have to ask for the fuses

  1. when is the last time anyone has had a short with an LED strand? Was it a squirrel that ate the wire and then shorted the copper?
  2. what power supply does not handle shorts nowadays? I guess you win because the fuse will take out just that one shorted strand and leave the other ones running

But yeah, despite the price, I found the pro expander convenient, including the build in 12V to 5V step down for the PB

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The danger with relying on the power supply :fire::

  1. Some power supplies operate in constant-current mode when there’s a short. Those will continue dumping their max rated amps into the short. Look for “hiccup” type supplies that disable power for a period of time before retrying, or ones that require a power cycle to clear a fault condition. Mean Well has great datasheets that you can get that give you all those details.
  2. Some shorts will be resistive shorts that may not exceed the trip current of your power supply. For instance, a short mid or near the end of a string/strip. Using a right sized fuse for each power run helps with this by being more sensitive and being able to fine tune it. You want one thats just a tad over your max current draw. Too large, and it may never blow when there’s a short.

There’s a number of ways shorts are caused. Not an exhaustive list:

  • Failed electronic components. Small MLCC capacitors are prone to shorting when exposed to temperature cycles and/or moisture. These are found in many LED modules, strips, and even inside some LED packages.
  • Depending on how it’s mounted, any movement could easily cause wear on the wire or strip and lead to a short over time.
  • Weathering can cause corrosion or breakdown of insulation.
  • Overheating wire can melt off insulation and lead to a worse short.
  • Animals, trees, cleaning gutters, etc.
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Very useful info, thank you.