PCB Suggestions and doubts

beginners
1

Hi again guys!

Hope you all are well.
This time I started designing a new PCB for another project.

Last PCB was power supplied by 3 wallmarts and due to that it was really heavy and not really confortable to transport.

Now im switching to use only one PSU (its actually a switched mode power supply), 5v 6A output.

The thing is that I have to power supply some 2812b led strips, and several components on my PCB with those 5v.

For connections, I choosed screw terminals to PCB (up to 6A each), but I decided to take differents inputs from the PSU to the PCB just to avoid the traces to get burn.

All traces has commond GND with Arduino Nano, but a separated live (+).

I designed first the BB view with my components and after that, I started designing my PCB.
I’m attaching 2 fritzing projects, one of them is with the actual configuration (with 9 ky003 modules plus mentioned above components) and the other one is the one focused to be on the PCB (since i’m using female connectors for data IN and also female connectors for the common ground and 5v+ from arduino).

Somehow, I got a mess on the PCB and now I’m Kinda lost. I tried to make the GND connections ootside the Nano Iitself (maybe im lacking on basic electronic theory, thinking to avoid high current passing through the Nano).

First, I’ll like to know if you, experts, can help me out with this design and identify the possible problems. (Something doens’t look well to me but I can’t figure it up what is it).

Second, about current flowing I’m not sure if the traces have enough widght to hold the current.
I calculated that the “LED CAJA” will be drawing at maximun 1,5A current and the LED MESA will be drawing 1A Max.

Took a look to several “trace widght calculators” but it doens’t make any sense to me, the numbers displayed are too large that not even Fritzing is letting me the option to set up the traces to that widght.

Will the current flow properly with this design? Will I have any problems like overheating or not enough current? Would you improve something on the PCB design?

Thanks very much for your help guys, I really appreciatte your hard effords with this noob…

Kind regards,.
Frozen Giant diagrams for PCB.fzz (92.0 KB) Frozen Giant diagrams.fzz (97.0 KB)

2

Have you also built and tested your project on a real breadboard or just did it in Fritzing. It sound like you want to power the LED strip through the PCB, which sounds unusual to me. But it depends on the length and density of your strips.

3

Hello Flaix,

Thanks for your answer.

I already tried this with BB but it was a little bit different. My PSU is on its way so didnt try it with the actual PSU.

Effectivly, im triying to connect the led strip directly to the PCB using female headers due to the resistors and capacitors needed on them in order to work. I did that in the past without any problems, but now, since im using only one PSU with some more current the doubts appeared.

THe wire lengh and the led strip itself wont be long so it should’t be a problem as far as I know.

4

Those 32 mil pcb traces should cary 2 amps each. Kind-of silly to have multiple connections to your power supply though. And looks like you are combining all of the ground traces, so that negates separate terminals, and will in total cary the 2 amps. You’ll want to separate those just like you did the positive wires if you want to keep separate power terminals.

I presume you are using those addressable LEDs?

The Nano has an onboard LDO voltage regulator, you probably don’t need to have an external one.

Why not put your LED output headers closer to your voltage input terminals? That way you don’t have to rout the traces around the nano. You also probably don’t want/need a capacitor for the LEDs.

You can always order a higher copper weight board. Going from standard 1 oz to 2 oz will double your current capacity at same track width.

You should still be fine with standard 1 oz copper with 4 amps. You need a 2+ mm (77 mil) trace for 4 amps and 1 oz copper.

Those 2.54 mm screw terminals are TINY. Still about 6 Amps each, but still. Go with a 3.81mm pin spacing, will get you 10 Amps. You have plenty of space on the board. 5.08 spacing will give you 15 Amps.

There’s two yellow traces on the right REALLY close to each other, probably not far enough apart.

You can try using EasyEDA; I found it MUCH easier than Fritzing. Maybe a slight learning curve at the beginning, but its wroth it. And you can specify any track width you want. Plus you can make fun ground planes really easy. You may need to watch a few youtube videos and read the FAQ a bit, but it’s well worth the transition. OMG, and the keyboard shortcuts. It’s so nice. Also, theres TONS of built in parts from LCSC. Like orders of magnitude more than Fritzing.

5

Also, why Nano and ESP8266? There are ESP8266 with LDOs too, which will allow for a 5v input. And also ESP8266s with plenty of GPIO.

I’ve done little research on the power requirements. Might be worth looking into a switching power supply rather than an LDO. That’s going to waste a lot of energy to heat. I see one thing saying the ESP8266 requires 400mA. Ya, that nano’s LDO cant handle that. There’s plenty of really small cheap buck converters all over (amazon/aliexpress/ebay) that will take 12v in, and then give you 5v out, or 3.3v out. Some may need configuration, others may be fixed to the output you want. Just found a few 3.3v 2A for $2 USD shipped. You can also build your own on your board, which was actually a fun project when for me when I did mine. The datasheets fro the DC-DC converters spell everything out for you.