Power Supply for 8x8x8 LED Cube and Arduino at the same time

Hello, I'm building an 8x8x8 Grayscale LED cube. Everything works fine so far, I only have one Problem:

Because the cube needs a lot of power, max 2-2.5A for 64 bright white LEDs at a time (one of 8 multiplexed layers). Since the Arduino can not provide nearly enough amps, I use an external power source for the LEDs, a lab power supply for now. The Arduino is powered by USB, the grounds connected of course. I switch the Layers using MOSFETs, the LEDs are controlled using 4 tlc5940.

Later, I would like to make a nice box with only one power plug.
I know I can use the vin pin (and gnd) on the Arduino to power it. But I read that this method needs at least 7v, but the LEDS run on normal 5v.

I'm relatively new to electronics so i'm not quite sure how to solve this correctly. My thinking is to use a 8 or 9v power supply (wall plug adapter) which supplies enough Amps for the project. I would power the Arduino via vin pin directly from the supply and use a voltage regulator kit to transform the voltage to 5v for the LED circuit.
Would that be the correct way to do this?
I didn't quite know what to search for so I'm sorry if this was discussed here before. If so, could someone post a link to a helpful thread?

AFIK if you feed the Arduino though the power plug (not the USB) its fine up to around 12V (double check the specs on the forum, but its somethink like that)

rogerClark:
AFIK if you feed the Arduino though the power plug (not the USB) its fine up to around 12V (double check the specs on the forum, but its somethink like that)

Thanks for the answer, but that was not quite what I'm asking.
I want to power the Arduino and my LED-Circuit from one single Wall power adapter. I would like to know if my approach (in the first post) is correct, I don't want to fry anything :wink:

Hi, just buy a 3A 5V switch mode wall-wart power supply. Connect the Arduino via its 5V connector (I.e. bypass its on-board regulator).

May be a good idea to put a big fat cap (1000 uF) on the 5V line, and make sure all your chips have a 0.1uF decoupling caps too.

Paul

PaulRB:
Hi, just buy a 3A 5V switch mode wall-wart power supply. Connect the Arduino via its 5V connector (I.e. bypass its on-board regulator).

May be a good idea to put a big fat cap (1000 uF) on the 5V line, and make sure all your chips have a 0.1uF decoupling caps too.

Paul

Thanks for the tip!

Is connecting directly to the 5V pin safe? I mean, will the Arduino work like that? And will I still be able to connect the usb cable for programming/serial data transfer without risk?
I guess this way I just circumvent the Arduino's power regulation... But that would indeed be the easiest solution and I wouldn't need to transform any voltages.

I will try it, thanks a lot!

I've been doing exactly that on a project I'm currenly working on, involving a 1m/60 RGB LED strip. It runs absolutely fine off the 5V 4A switch-mode wall adaptor alone, and I have been uploading sketches while the adaptor is still connected with no ill effects.