# How much current can arduino ground absorb?

I am currently working on an LED 4x4 cube, so here is my pre planned circuit diagram.

https://easyeda.com/editor-mobile/#id=ffca9f3303f242a185b950b0bee4fa29|

1. I am to connect 220ohm to each positive terminals.(16)

2. I am to use 4 transistors(2n2222) for 4 negative layers of which, collector terminal will be connected to the negative terminal layers , base will be connected to 4 analog pins through 1k ohm, and emitter to be connected to the GND pin of arduino. Using transistor as a switch.

Can my studio ground get damaged if connected directly without a resistor.

If no?

Is there any way to make it?

Explanation with circuit diagram will highly be preferred...

• Ordinary LEDs take 20 mA at most, and they are already bright enough (to my taste at least) at 10 mA or even less. If you get 1 A for 16 LEDs there is probably something wrong with your current-limiting resistors. Commented Sep 27, 2020 at 9:50
• That's right @busybee but, I am to make driver for sure , but before it, I wd like to test it connecting it bare (maybe resistors)on arduino pins. Commented Sep 27, 2020 at 12:29
• @Gerben yeah I recently spotted my mistake thanks for the advice, but if I make a voltage amplifier using transistor and then, I guess I will be able to run all the LEDs together right? Commented Sep 27, 2020 at 17:36
• PS could you share what the mistake was? Commented Sep 27, 2020 at 18:29
• What should be the delay() time of blinking those LEDs? delay(10) will be enough I guess Commented Sep 28, 2020 at 3:00

No your gnd won't get damaged if you source current through it. If u need explanation let me know

You are asking the wrong question. It does not matter how much current the arduino ground can adsorb, it was designed for what it needs not what other devices may need. What you want to do is connect all the grounds at the power supply (please tell me you are not using the arduino 5v for this). You might look as MOSFETs as you will have a lower voltage drop and much easier to drive.

• I am connecting all 16 positive pins to arduino pins 0 - 16 through 220ohm resistor and then I am gonna connect the negative layers to the ground using transistor and transistor's base will be connected to the rest of the 4 pins Commented Sep 29, 2020 at 9:52
• None of the power output pins were used Commented Sep 29, 2020 at 10:48