Led strip flickering

I started an led project about a month ago. I’m building nanoleaf like led hexagons by winding a ws2812b led strip through the inner edges of the hexagons and controlling them through an arduino mkr 1010. However they need more amps than the arduino can supply so I’m using an external power supply with 5 volts and 10 amps. Every time I run my code and plug in my arduino the leds start flickering. I have no idea what the problem is because there’s nothing wrong with the code I tested the power supply with a multimeter and it’s giving off the right voltage and amps and all the connections are right. I’ve tried putting a 100 um capacitor and all the lights just turn off. I’m just so confused and I really want to finish this project because I’ve spent a lot of money on it.

Post your code. Post a schematic of the project.

A 100uF cap is most likely an electrolytic cap so is polarity sensitive. Did you, by chance, connect it backward. If so, dispose of it and try with a new cap being very careful to observe polarity.

You should also have a 470Ω resistor between the Arduino output and the Din of the first pixel.

Is the arduino mkr 1010 a 5V device?

For a long string of LEDs, you may need to inject power in the middle and the other end to get even voltage to all pixels.

Read the forum guidelines to see how to properly post code.
Use the IDE autoformat tool (ctrl-t or Tools, Auto format) before posting code in code tags.

Did you connect the GND from the Arduino to the GND on the power supply?

@urboirlcoochie, your topic has been moved to a more suitable location on the forum. Installation and Troubleshooting is not for problems with your project :wink: See About the Installation & Troubleshooting category.

Hi! So I’m away from my house and I don’t have access to my code and I also don’t have fritzing so I’ll just list my connections. Power supply + -> led strip +, power supply GND -> arduino GND, arduino GND -> led strip GND, arduino 4 pin, led strip digital. Arduino is powered by separate power supply. So I tried a different capacitor and it didn’t turn the led strip off but it didn’t make much of a difference so I just ordered a 1000 uF capacitor so hopefully that will make more of a difference. I have a 550 ohm resistor and a 220 ohm resistor. Do you think I could use one of those? Or should I get a 470. The MKR 1010 is a 5 volt board. Also I haven’t tried connecting the power supply to the other end of the strip but that might be needed.

@missdrew yes I did

Either resistor will be OK and better than none.

Long strips may need power injected at more than one place, not just at one end or the other.