My LED matrix constantly sparks and stops working.

Using Arduino LEDs and Multiplexing
1

Hi, complete Arduino newbie. I'm building an LED matrix which can connect by Bluetooth to phones, which allows people to play Tetris on the board.

My problem is, every 2-3 times I plug my matrix into a power supply, the wire connecting the board to V+ on the power supply sparks a little, then the first LED has to be replaced for some reason.

I've wired 200 leds (20x10) exactly like this video: Make your own 10x10 LED Matrix - YouTube (4:09 onwards), with four wires connecting the first LED to the power supply + the Arduino (one 5v and GND to the power supply, and Data In and GND to the Arduino, and the Data In is connected to a 220 Ohm resistor).

I'm using a 5v20A power supply, and these lights: https://www.amazon.com/ALITOVE-Individually-Addressable-Flexible-Waterproof/dp/B00VQ0D2TY/ref=sr_1_4?ie=UTF8&qid=1513180129&sr=8-4&keywords=ws2812b+leds

I'm very frustrated as I've had to fix this matrix about 5 times, and I don't know what's wrong. Thank you!

2

That video is a bit crap. It does not show the resistor and capacitor you need to protect your LEDs from blowing like they so. See this Best Practices | Adafruit NeoPixel Überguide | Adafruit Learning System
All joints should be soldered so there is no sparking.

3

It is possible that the 5V 20A supply rises to more than 5V with no load attached, so if you turn on the power supply and then join the wires to your display it could fry something.

I'm not surprised by it sparking, you are suddenly connecting a something that's taking quite a few amps, but frying just the first LED is a bit of a puzzler.

Really need some more information on this one: type of power supply, a schematic diagram and a picture of your project would help us figure it out.

Yours,
TonyWilk

4

but frying just the first LED is a bit of a puzzl

No it is not, it is exactly what you would expect if you wired it up like that video.

5

Grumpy_Mike:
No it is not, it is exactly what you would expect if you wired it up like that video.

I watched more of the video this time.... eek !!

Ok, it's not much of a puzzle any more :slight_smile:

Yours,
TonyWilk