How should I place resistors while using a power supply?

Using Arduino General Electronics
1

I have an LED matrix that requires an additional power supply. Should I place a resistor on both the power supply GND and the Arduino GND, or should I only place it on one of them?

2

Neither!

3

What LED matrix?

What power supply? Volts? Amps?

What Arduino?

Why do you think that you may need resistors?

A schematic would be welcome.

4

16x16 LED matrix
5V 20A power supply
Uno
I've always used them for LED's

5

What do you mean by this? :face_with_raised_eyebrow:

7

An explaination would be appreciated

8

Are you talking about current limiting resistors for the LEDs?

9

On my LED matrix there are 5V and GND cables for a power supply and DIN (data in since the LED's are addressable), 5V and GND for the controller (an Arduino Uno in my case). I am wondering if I need to use a resistor at all, should I solder it to the power supply GND cable, should I connect it to the Arduino GND on a breadboard or maybe should I do both.

10

Indeed.

11

The LED matrix LEDs are individually addressable? Are they WS2812 LEDs? If they are, you don't need any resistors for it.

Could you post a photo of the matrix? Or a link?

12

We need to know the exact LED matrix. Post a datasheet or a link to where you got it.

13

ws2812b

14

It was fairly clear from #4 that it was a WS2812 matrix.

What makes you imagine a resistor in the power supply is in any way intended?

It operates on regulated 5 V. If you have a regulated 5 V supply, you connect it.

Your "Din" and ground connections go as a pair back to the Arduino, but you should include two components at the matrix terminals - a 470 Ohm resistor in series with the data line, and a 470 µF capacitor in parallel to the 5 V and ground.

You can - and should - power the Arduino from the 5 V supply to the matrix. the 5 V wire should also run together with the data and ground. If (unfortunately) using a UNO (or Mega 2560) you need to disconnect this (only the 5 V line) from the "5V" pin whenever you connect it to a PC via USB.

So - from where did you get this other resistor notion? :roll_eyes:

2 Likes
15

This topic was automatically closed 180 days after the last reply. New replies are no longer allowed.