New Product Fail - Addressable Curtains

I was really hoping I found a new winner. A 300 LED 3m x 3m fairy light curtain. It had 3 wires and the included video clearly showed they were addressable. The attached USB controller looks identical to the ones that come with the fixed address fairy lights so I was really hoping I’d have a 30x10 matrix for under $30.

But when I took apart the controller, the pins are just labeled 1, 2, 3. I cut it off and attach a JST assuming the pins will be the same as the fixed address lights. They turn on all blue, no control. I figure maybe data and ground are swapped. Now they are all aqua, still no control.

I solder on a JST to the original controller and hook it back up. I haven’t broken it. I did notice the controller emits a highly pitched buzz that changes pitch depending on color. Now I need to put it on the oscilloscope and figure out what is going on. Except I don’t have one and never used one. :thinking: 82929C2F-7325-490F-8084-1D5CAEFC840D.jpeg…

Simple check on the USB controller, you should be able to measure ground on the USB pins and match it to ground on one of the 3 outputs. If you can do the same thing with the USB +5V pin to one of the other 3 outputs, then you’ve verified it’s at least a 3pin “standard” of some sort.

If you can’t map the USB power to the outputs easily, then you may have some sort of double diode 2 pin led’s??

Just so I’m clear, you’re saying use continuity tester between those?

An Ohm meter (multi meter) would be better if you’ve got one.
It would be good to know if the Gnd and power connections from the the USB port are hardwired out to two of the 3 input wires (resistance <0.3 ohms). If you’re assuming these things are like the other USB fairy lights then that’s what I’d expect. You might be able to physical see the traces if you take the USB case apart and examine the PCB carefully.

Do you recognize any of these components? It looks like all three pins are modulated. Pins 1 & 2 had the same resistance across usb 5v pin, 0.4 ohms.
I checked the voltage on the pins as it was running and they were all varying wildly.

Looks like an “H-Bridge” setup or possibly a sort of 3-Phase Y.
My guess would be you’re looking at 6 MOSFET drivers, the set closest to the IC have their Source pins connect to Gnd and the other set to +5V (I might have that backwards, can’t tell from the photo).

Depending on how you drive the 6 input pins, you’ll get different polarities of +ve and -ve across green to white, green to red, AND red to white.
My guess if you were to disconnect white and green and connect them across +5V (with an inline 100R0 resistor for safety), you’ll get some colors. If you simply reverse the polarity you’ll get different ones.
Same should apply for red and white AND red and green.

It’s a cheap way of “simulating” the real addressable LED’s we know and love.
I’m sure there’s a way to make your own controller with an ESP32 or arduino, but WLED is not the software to solve this problem (IMHO).

1 Like