Hi everyone,
I have a problem of heating with my project.
I have to power more than 100 WS2812 LEDs that require a considerable current, abour 6 x 10^-3 A each, that 100 times equals a 6A current in total.
I would like to power the led string with Arduino, so that the 5V output can be connected to the LEDs, and to do this, I have to power the Arduino in turn with a transformer (5V - 10A), but when I power the Arduino with the transformer, it overheats in few seconds. :~
Does the Arduino provides to be alimented with this kind of transformer?
Is the overheating caused by the massive current? Can I solve the problem anyway?
The Arduino overheats, especially the Voltage Regulator component, next to the Power Jack.
Yes, the transformer provides DC.
I'm sorry, I meant 60 x 10^-3 A.
Basically I'm just plugging the transformer DC output, directly into the Power Jack, so that the whole Arduino Board is powered by the transformer, and then the LED strip can directly take the current from the 5V output on the Arduino Board.
You cannot safely draw more than about 20 mA from any one output pin, and no more than 200 mA from the Arduino chip, PERIOD.
You need an external driver and power supply for the LEDs.
As others have noted, the Arduino cannot drive 100 LEDs without the help of external components. Well, not without likely exceeding the limits of the Arduino. Ditto for the voltage regulator, it's not meant for large loads. That said, Neopixels/WS2812 units don't require a lot of power on command/control pins, just on the power pins. So, you should be able to connect 100 these LEDs to the Mega without issues, but only as long as they do not derive their power from the mega board. At the very least, make it a separate connection to the common power supply.
Furthermore, I would suggest having a deeper look at all the excellent resources that Adafruit has published re: using the WS2812 or NeoPixel as they like to call it. In particular, look into how they want you to hook up the LEDs.
If memory serves, using two power supplies is encouraged, i.e. one for the Arduino, one for the LEDs, with a common ground. That way, if the LED power supply goes down due to overheating or the power quality suffers due to transients, it won't be as likely to affect your Mega. Given the cost of a Mega, I'd also investigate the use of a buffer chip to make it that much harder to smoke the Mega. PJRC.com has some good tutorials in this regard since their MCU runs on only 3.3V and therefore pretty much needs a buffer chip.
I would also verify the output voltage of your external power supply, just to be sure that you don't release the magic smoke from the NeoPixels. Lastly, verify the input voltage range for the voltage regulator / barrel jack on the Mega. IIRC, it prefers something like 9V, not 5V. At 5V input, the regulator should be going into dropout, doesn't seem like a good idea.
Since you don't appear to be controlling the LEDs with the Arduino (the LEDs are powered-on whenever the Arduino is powered-on), you can simply connect the LEDs to the 5V power supply, instead of going through the Arduino's regulator.
Hi, I think you have got some problems with understanding what you need to do.
The Arduino will CONTROL the LEDs.
The power supply will provide POWER for the LED's.
The the power for the LEDs does not go through the Arduino, or is supplied by the Arduino.
Also you cannot have a DC Transformer, it should be an AC Transformer with a rectifier and filter capacitor.
Please post a pic of your project including the "DC Transformer"
