Everything you didn't want to know about Kmart pixels

Katekate

Katekate

Senior elf
Joined
Jan 1, 2020
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Location
Portland, Vic
So. Kmart has pixels.

1637911713480.png



$39 for a 50 count string with controller.

So whats the deal? I bought a set to find out.

You can't read anything on the chips, but the PCBs have WS2811 printed on them.
1637911860652.png
They are sized just like normal bullet pixels, here is one next to a 12v regulated raywu
1637911827451.png

Here is the controller. Barrel jack for input (USB-A to barrel jack lead included), JST on the output, and a IR receiver.
1637911790986.png
And here is the inside
1637911941790.png
1637911986840.png
Pretty unremarkable. A quick google of the chip suggests it may be reflashable. Possibly with WLED even.
 
Here is the chip.
1637912108090.png

From a subjective point, they seem just as bright as any other pixel. The controller does seem to be limiting the brightness in some modes to keep the current draw under 1A.

Testing the strings on another controller, I was able to pull 1.2A on full white. around 700mA on full single colours. Cyan Magenta Yellow all around 1A.

I wanted to try the controller on wifi, but I wasn't able to get it to join my network using their app.
 
So in summary, its 50 5v pixels and a cheapy controller you could buy off aliexpress. A little more expensive than what you would pay out of china, but nothing really out of the ordinary there.

If your display was 5v and you needed some pixels in a hurry, they would certainly work with normal controllers & xlights.
 
I went and bought a box of these this afternoon just to run some tests on.
I sacrificed the last pixel to find out the chip used, turns out it is a TM1903L using normal 2811 protocol.
IMG_0015.jpg

The pixels themselves are well made.
The last pixel does not have any wiring to extend the string which is a negative.

The wiring is 20awg and with 2M of lead you get 1v drop along the 2M of cable when on white which explains the reduced current draw compared to individual colours in the table below. They are running in CC mode as voltage changes don't impact current draw for individual colours only white.
Dual colours were drawing >1.14A and again were voltage limited as an increase in source voltage resulted in a rise in current.

K-Mart PixelsVpsuVin at lead startCurrentCC value
50 unit string
Red
5.1​
5.05​
0.74​
14.8​
Green
5.1​
5.05​
0.72​
14.4​
Blue
5.1​
5.05​
0.72​
14.4​
White
5.1​
5.02​
1.29​
NA - voltage limited

I couldn't get the WiFi to work but i don't have discreet 2.4ghz points and all my mobile devices connect to 5ghz so that may just be me.

Cheers
Phil
As Kate suggesting in chat these could be good as wearable lights with a USB battery bank.
 
yeah the documentation says 2.4ghz only, and I even turned 5ghz off to see if that helped. my phone doesn't seem to have an option to force 2.4ghz on a mixed network.
 
Thanks for the extensive summary on these, guys :)

I did wonder about them when I saw them in my local store - and considered grabbing a set to throw in the Christmas tree at worse.
 
I just purchased these and was surprised by how bright and vibrant each led is. Does anyone know how they compare to twinkly leds?
 
I have recently bought a athom wifi pixel controller

Can take 5/12V input Would this mean i can connect the pixels up and control through this devic?
 
probably. Got a link to the specific controller you bought? What are you trying to achieve?
 
aaronwa said:
I have recently bought a athom wifi pixel controller

Can take 5/12V input Would this mean i can connect the pixels up and control through this devic?
Click to expand...
Yeah, I've done it with all the Kmart pixels I bought, took out the boring stock controller and added an esp01 module to run them, so anything that can run ws2811 pixels (I'm using the WLED software) will work.
 
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