WLED + ESP32 + TC4427 5V 1A+ Data

Spent a while making this so thought I’d share it here - these are my all-in-one WLED boards with a nice strong 5v 1 amp+ data output since I have runs over 5M, working no issues :slight_smile:

Went for the external antenna ESP32 chips for a better signal too.

Case could still use some tidying up but I had to draw the line somewhere :slight_smile:

Has protection on the USB/DC inputs so you can flash it without unplugging everything too :wink:

For some reason I can only put one image in each post:

Looks good!
That 4427 driver should work well for WS281x and SK6812, etc types.

I’d be interested to know if you’ve tried with APA102 style (CLK/Data)?
Those run at much higher freq. (10-20Mhz) and the data sheet doesn’t specifically note the max for that chip.

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I haven’t tried it with them I’m afraid but I can confirm it works great with SK6812 types.

I can’t find much about calculating mosfet max frequencies:

If I’m understanding this right then you’d need a mosfet with a 0.05ns charging time or less which I don’t think even exist so that can’t be right…

Easier to work from the rated rise/fall times of the device outputs and do some guesstimation.

The TC4427 is rated at 40ns rise and 40ns fall, that’s 80ns per pulse or the equivalent of a 12.5Mhz clock.
At 20Mhz clock for an APA102 you have only 50ns of time per pulse.

Now, the typical rise/fall time may be (much) better than the guaranteed rating, so it may work ok.

NB: this is not a knock on your design(!!!) I just noticed what may be an edge case for usage.
Admittedly, I’d guess a large portion of WLED users (>75%???) use the WS281x/SK6812 style devices.

On another note, are you posting the design to open-source, setting up for sale or both?

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Right I get you, worth a try though I guess maybe I’ll get an APA102 strip at some point and see.

If people are interested then I’d work out some batch costs and prices for the pcbs. I spent a bit of time on it so I’d prefer to keep the schematic private for now, pretty much all the circuitry is out there somewhere :wink:

Looks great, What board type is this?

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Thanks :slight_smile: they’re my own custom ESP32 (WROOM) boards

I do like the casing and antenna’s are underrated.

but the 1 amp for data ehhhh the 2812 chip has one leg data in and one data out. on a strip, there is only one single LED-chip connected to your feeding box. Then the data is daisy-chained on to the next etc. regardless of the number of LED-chips, they all have only one connected to both in and out. That is the whole fun idea of these strips. The adress of each chip is just it’s position in the row.

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Of all the shifting options I’ve tried for my 6-7m data cable runs, these are the only ones that worked without any issue at all

you mean 6-7 meter cable between the controller box and the LED strip?

I can imagine that takes a bit more for the driver, as the “frequency” of the code is in the range of 1MHz (one bit is 1,25 us) the capacitive load of wires may round off the flanks of the high-low and low-high transitions.

as for the powering of longer strips, do you use midspan support / extra 5 Volt leads that feed in halfway?

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Yeah 6-7m between the strip and the controller. Works great for SK6812s for me.

My strips aren’t longer than 5M individually so I can get away with 5V to each end and full brightness. Using either 16 or 18 AWG cables

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