Buying an adapter, do i need 5v or 10v?

Hi im about to do my very first electric project, its a speedbar for my car using a obd2, arduino, and some led panels. It is meant to react to my cars speed and I intend to grab power from my 12v cigarette lighter and throw a 5v adapter in the circuit for the 5v panels.

The led panels are capable of pluging in one to another, through a 3 pin port they have, (ground power and data), the panels themselves are 5v and made with series conections (their leds). id wish to connect two of them through the ports I mentioned.

So what is exactly is happening here?

Are they adding voltage and now im supposed to get a 10v adapter for two of them instead?

Im also confused about the Amps the product says 0.05 amps and 0.25W per led and each panel has 256 leds.

So my math is: For 1 panel, 13 amps and 64w For 2 panels, 26 amps and 128w does this make sense? I just don't want to buy the wrong thing :S

This are the panels im buying: https://www.amazon.com/gp/aw/d/B09578W9MT/ref=ox_sc_act_image_4?smid=A1CJB5SYI9X4XC&psc=1

by Dr_arell
August 30, 2021

I chased around trying to find solid data on these panels and it is, to say the least, sparse. But from previous work I've done using the 5050 neopixel each colour of one neopixel will require about 20 ma (turned full on) so one neopixel with all 3 colours on at full brightness will require about 60 ma. The voltage required by a neopixel is 5v and they are all connected in parallel with respect to voltage supply so this must be maintained at 5v. The total current required is a different story. If you turned everything on at full brightness in your case this would add up to 20X3X256=15360ma or 15.36 amps per panel!! But you are not going to do this so it's time for some systems engineering. Plan out what you are going to write to the panel in the worst case, decide which colours to use for each pixel then add up the currents (0 current for a dark pixel). You will find the current required is much less than 15 amp per panel; if you are writing text it will be much much less. For multiple daisy chained panels keep in mind that the little JST connector on the first panel must carry the current for all following panels so for multiple panels it is wise to feed them in parallel with respect to the 5v and ground connections. The DIN and DOUT connections, however must be daisy chained from the first to the last panel. So my advice is, do the systems engineering, draw up a schematic diagram and make sure it makes sense.

by Foxx
September 02, 2021

I did not think about that actually, i will do the power consuption diagram you suggested, im gonna be using 1 or 2 colors at most maxed out on both panels, so im going to work around that.

Your comment was very helpful, thank you so much for replying.

by Dr_arell
September 03, 2021
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