How much current can arduino ground absorb for 4x4 cube?

:smiley: bro, can u please check the code above whether there’s a problem, I don’t think it should have one…

delayMicroseconds(2);

That's 1000 times faster than is required to avoid flickering and will make the cube dim. Use delay(2).


I just noticed the yellow led line has higher forward voltage than green. Otherwise the forward voltages of each colour are proportional to photon energy. I suppose it could be due to the chemistry used in yellow or green leds, but seems like a strange anomaly.

PaulRB:

I just noticed the yellow led line has higher forward voltage than green. Otherwise the forward voltages of each colour are proportional to photon energy. I suppose it could be due to the chemistry used in yellow or green leds, but seems like a strange anomaly.

Yep, this question once occurred to me too but didn’t take it that seriously! Well, I am to make it with either blue or white or green.

Well bro, can u suggest me a rechargeable 9v battery, which shouldn't be much heavy, and must be suitable for light projects and cost must not be more than 10 United States Dollars?

You do not want or need a 9V battery. Certainly, a PP3 size 9V rechargeable battery will be useless.

I would recommend 4 x AA NiMH rechargeable. Connect these to the 5V pin, not the Vin pin. But never use 4 x AA non-rechargeable like that, their voltage would be too high.

Nice choice for arduino robots and cars, but , for drones , wouldn’t it be so heavy?

So you are putting your LED cube in a drone? :astonished:

Paul__B:
So you are putting your LED cube in a drone? :astonished:

Now that is ambitious... :o

Paul__B:
So you are putting your LED cube in a drone? :astonished:

Lol lol lol lol No, i have planned my last project to be a drone one, which I am going to make almost one and half year later,

By the way , you are so funny :smiley_cat:

TheUNOGuy:
Now that is ambitious... :o

Oh come on lol I didn't mean that :slight_smile:

bitrux:
must be suitable for light projects

Ah, so by "light" you meant "not heavy" rather than "producing illumination"? We have been discussing an led cube, so you can understand why I assumed you meant the latter!

PaulRB:
Ah, so by "light" you meant "not heavy" rather than "producing illumination"? We have been discussing an led cube, so you can understand why I assumed you meant the latter!

Oh, sorry :smiley: , will LiPo batteries be good choice for me?

I need to use those batteries in both, light and heavy projects without any major problem.

The main problem with LiPo batteries is their low voltage which is not enough for a 16MHz Arduino like Uno or Nano and not enough for your blue leds. You could choose an 8MHz 3.3V Arduino like a Pro Mini, and LEDs with a lower forward voltage such as red, yellow or some green leds.

What, if I connect the batteries in series and then ?

Then the voltage will be too much to connect to the 5V pin, and would damage the Arduino if you did. But you could connect the series batteries to the Vin pin. Then the Arduino's built-in regulator would reduce that down to 5V to power itself and the cube. You have to be careful using the built-in regulator. It can easily overheat and shut down or be damaged if too much current flows through it. But I think your cube will not draw too much.

The downside to using the built-in regulator is that it will inevitably waste some of the battery's capacity. The extra voltage 2 x 3.7 - 5 = 2.4V is simply burned off as heat. This makes it only 5/7.4 = 67% efficient, and 33% of the battery capacity will be wasted.

If you want to maximise your battery life, get a DC-DC converter module, set it's output to 5V and connect that between the batteries and the 5V pin. These are much more efficient, and 80~90% of the battery capacity will be used.

Buck converter?

bitrux:
Buck converter?

That would (as PaulRB says) indeed be the best way to provide 5 V from two or more LiPos with sufficient current and most efficiently to power your LEDs.