adding power hungry equipment to my arduino

hey guys,

a simple question,
i will need to add some input and output stuff to my arduino board, which will also need power ofcourse.
all this will draw a couple of amps, way more that what my arduino can supply so i will need to add a additional 5V power supply that will power all this.

concerning the connection i have a few questions (mainly because i see different setup options online)

let's take a ws2812b ledstip as example.
3 wires connected..

Din, 5V and Gnd

i saw 3 options:

  1. DIN, to board and connect the external psu directly (and only) to the ledstrip, don't connect it to the arduino board

  2. DIN, to board and connect the external psu directly to the ledstrip, AND connect that ground to the arduino board's ground.

  3. DIN, to board and connect the external psu directly to ledstrip and arduino board, so both ground to ground and 5V to 5V arduino out (so parallel)

  4. other option if the once above are not save.

anyway, how can i do this safely without blowing op my board.

many thanks :slight_smile:

greatz Matt

  1. DIN, to board and connect the external psu directly to the ledstrip, AND connect that ground to the arduino board's ground.

That is the way to do it with the exception that the Din line from the strip should go through a 470 Ohm resistor to the Arduino board output. It is also recommended (in some cases) that a 1000uf electrolytic cap be placed across the strip 5V power input as shown in this guide.

@ groundFungus :

thank you for your reply.

in this topic the ledstrip is just used as an example of a "power hungry" attachement,

the issue of the question for me is really just about the power connection, not so much the control lines.
Although i will definitely take your advise in account i would like to verify that i understand things right attaching other power hungry attachments (as they will all be attached on something like a power "rail")

so let's change the ledstrip into a display, if it needs to be specific let's say a nextion nx line display but i don't think it should matter also, please leave the control lines (Rx and Tx) out of it, unless it's really neccessary for the discussion.

should the connection then still be the same, just connect the ground wire to the arduino board's ground, thats it?

And just to be sure.. adding a cap over the input to the rail (so all the attachments) would be oke too right?
it's just to take out the noise out of it right?

additional.. what would be wrong with option 1) so only control via the arduino and power completely seperate?

sorry for kinda asking again. just like to also know the "why not" just as much as the "why",
Also just want to be sure as it will be using quite a fair amount of power and blow the board in an instance and since i have really difficult excess to it so i would really wanna avoid stuff like that happening.

greatz Matt

what would be wrong with option 1) so only control via the arduino and power completely seperate?

This would be wrong:- Power Supplies

oke :slight_smile:

thanks, heb t begrepen en zal dat stuk eens goed doorlezen.. maar zie nu de logica

grtz Matthieu