how to power 50 arduino nano's off one power supply?

im new to the world of arduino and i have a work project where i need to power 50 arduino nano boards off perforably off of one power supply. i would like to use the mini usb connector that is built in to supply the voltage to the board to keep things easy to remove and reprogram when needed. each nano will have 3 3mm blue leds running all the time as blinking lights via a timer. with that said i just don’t know what 5 volt power supply to get and how many amps i will need. i would think a 5v 14 amp 70 watt mean well NES-75-5 would do the trick but i wanted to make sure that the boards can handle that power supply with that amperage running through it.

any help would be fantastic

thanks in advance

That sounds right to me.

Devices will only take the amount of current they require, provided you apply the correct voltage.

As long as the device is a regulated power supply, you're fine (there exist some old power supplies that are not regulated, often found as wallwarts - these provide a higher voltage than specified under light loads and can damage connected devices). These unregulated supplies are less common now than they used to be, but they do still exist, and it's hard to tell which you have without measuring it under no load conditions.

Welcome to the forum.

What is the application that needs that many controllers?

How many LEDs is each controller using?
Are the controllers all in the one location?
What is your electronics, programming, arduino, hardware experience?
Is this a school/college/university project?

Thanks.. Tom.. :slight_smile:

Do these LEDs have to be 3mm?

I would suggest changing your design. Use 1 Nano and 150 ws2812 leds. You will still have individual control over each led, plus you can fade and change colour of each led. And if you need to change the code, you can do it once instead of 50 times!


you asked about power supply and that was answered, however, you have us curious.

using shift registers, we Could run 150 LED's using 1 NANO and timing each LED independantly.

about 2/3 the way down this page is a board that can drive 64 LED's.

it sounds to me too that ws2812 and one board makes much more sense, but of course that depends on the application, from which we are all very curious.

In case you would go with 150 pixels of a ws2812, each pixels work with 60mA at maximum power (white), which means that you would probably be fine with 9 Amps.

I'm not sure of the real difference between a couple of Nanos, port expanders or other devices, which all have to be powered somehow. The stability of the supply voltage has been addressed already, and I'd like to add voltage drops and precautions against power short circuits, in such a large installation.

How can one be sure that a 9A power supply will not increase its output voltage to dangerous values, when a large percentage of the lights go on and off simultaneously? Will a couple of linear voltage regulators be required, to keep the voltage within acceptable limits throughout the installation? This would also secure the installation, because each regulator is short tolerant (foldback).

What about the many power line caps, when the entire installation is switched on?

The microcontrollers themselves support a broader range of supply voltages, so that an effective voltage of 3-5V (or 2.2-3.8V) would be tolerable, for a certain amount of time. That's why I'd suggest to use Minis instead of Nanos, with lower power and voltage requirements, and 150 USB connections are not really practical and thus not required.

Any comments?

to all that our curious. i am making a display for a battery manufacturer. i will be placing a nano inside each of the 50 empty battery shells that will randomly blink the 3 battery status indicators that will match how the actual battery would normally display the status then i am waiting all at random intervals before repeating the process to give the display some life. i am using individual nanos as they want to be able to remove the battery from the display using the normal battery clip release so i will be pushing the 5v power through the battery terminals which are being re-purposed for the nano board

like i said im kinda new here to this world so im using a basic blink code posted below
im using 3 standard 3mm blue leds lights with 220 resisters

int LED1 = 4;
int LED2 = 5;
int LED3 = 6;

void setup() {
pinMode(LED1, OUTPUT);
pinMode(LED2, OUTPUT);
pinMode(LED3, OUTPUT);

void loop() {
digitalWrite(LED1, HIGH); // turn on LED1
delay(200); // wait for 200ms
digitalWrite(LED2, HIGH); // turn on LED2
delay(200); // wait for 200ms
digitalWrite(LED3, HIGH); // turn on LED3
delay(3000); // wait for 3000ms
digitalWrite(LED1, LOW); // turn off LED1
delay(20); // wait for 20ms
digitalWrite(LED2, LOW); // turn off LED2
delay(20); // wait for 20ms
digitalWrite(LED3, LOW); // turn off LED3
delay(5000); // wait for 5000ms before running program all over again

so im using a basic blink code posted below

So, what is the problem?

it comes down to power and the board i use. so i ask for any help anyone can give me on how to choose the correct items im still going to use individual boards for each display with 3 3mm blue leds per board

i just noticed that the nano is discontinued so i can switch to an Arduino Pro Mini 328 - 3.3V/8MHz from spark and then use my mean well 5v 70amp power supply to power them all up. would that be a correct statment since im with in the DC input 3.3V up to 12V range

that should give me plenty of head room on power. the question i have is should i still put something at each board to keep things safe and if so what should that part be

thanks in advance for any help you may be able to provide

the question i have is should i still put something at each board to keep things safe and if so what should that part be

Would you feel you needed to if there was just one Arduino? I wouldn't.

Why does having more than one Arduino change anything?

Nano is not really “discontinued”. You can buy them from many clone manufacturers at very cheap prices.

Other options would be Arduino Pro Mini, as you have found. You will need a USB-serial adaptor to upload your sketch to them.

Something based on atmega328 is really overkill for your application. An attiny45/85 based board would have enough resources. Like these.