Will 2 amps kill my arduino?

Will 2 amps kill my arduino? :o

2 amps where?

Wow, what a detailed and thurough question rolls eyes

If you're talking about the 9v power supply, no it won't kill it, it means that you can pull UPTO 2A from the combined stuff connected to the Arduino(the board itself needs ~200)

If you want to run 2A off a output pin, DON'T it WILL KILL the pin and, your ATMEGA-164, or even the board itself. The MAX that each pin is rated for is 20MA(mil-amps)

If you want to provide a 2A INPUT on a pin, I'm not sure, but it could possibly fry the board. Depends on whether the board uses what it needs to trigger or all of it.

If you want to run 2A off the 5v output pin, I'm not sure, but the Voltage converter only supports ___ and you'd have to have a power supply rated at ~2.5-3

If you want to provide a 2A INPUT on a pin, I'm not sure, but it could possibly fry the board. Depends on whether the board uses what it needs to trigger or all of it.

I haven't try so I don't know, but I think there will be that nice typical roasted electronics smell around if you do such a thing ^_^

Yeah, I assume it would kill, but it brings the possibility of the input being "Cumulative" so like it'll only let xma passthrough(like the power supply)

I was 85% sure it would fry it, but didn;t want to be 100% wrong :P

Seems like much current to block for such a tiny device.... I'll bet on the "roasted plastic" ending. The Atmega168 doc states nothing on a difference between I and O limit :

28.1 Absolute Maximum Ratings* DC Current per I/O Pin...............................................40.0 mA DC Current VCC and GND Pins................................200.0 mA

I think you're 98,43% right. ^_^

a new category is needed for questions like this....

Yeah, I assume it would kill, but it brings the possibility of the input being "Cumulative" so like it'll only let xma passthrough(like the power supply)

I was 85% sure it would fry it, but didn;t want to be 100% wrong :P

The connection from the pin to the wafer inside the chip is a gold wire much, much thinner than a strand of hair. If you tried to run 2A though this wire, it would melt like a fuse so the pin would no longer be connected to the wafer. The pin would be dead, but there's a good chance the rest of the chip would work. Though you might also fry the whole chip that way.

This is why a little static shock can destroy a microcontroller. You're talking about circuits comprised of a incredibly small, delicate components only 10s of atoms thick. A few 100 A, even for only a fraction of a millisecond, can make such delicate things go poof.

  • Ben

I doubt Atmega-164's are THAT small.

But yeah, anyways, question solved.

Hey, I didn’t say how many 10s of atoms thick :P. I guess at the moment AVRs are using maybe 0.35 micron technology, which would be on the order of 1000 atoms, but I believe they have CMOS features with metal-oxide layers that really are only 10s of atoms thick. Of course more cutting-edge IC manufacturers such as Intel are down to a crazy 45-nanometer technology, so there you really are talking features on the order of 100 atoms.

  • Ben

It's important to specify that, due to problems in the originals computers, miniaturization have gained success because it prevented cockroaches entering the computers and dying burned between two lamp contacts, causing awful shorts.

With such small technology, no insect can get inside, and with the extremely low power, they can't burn between two pins.

Engineering is a wonderful world.

You can't get 2A off an output pin; the internal resistances inside the chip will prevent it. I suspect that you can short circuit Arduino output pins to GND (or +5V) for quite some time before you damage the chip irreparably, although doing so is outside of the specifications. MANY circuits of dubious merit connect LEDs directly to IO pins with no current limiting resistor, and those seem to run fine forever.

You can't push 2A input an input pin, because the input pins are CMOS gates, and draw effectively zero current (infinite resistance.) If you manage to measure ANY noticeable input current, that probably means the chip was already fried.

I SUSPECT that wjat the original poser meant was "can I connect a power supply rated at 2A to my Arduino." The answer to that is YES. However, you won't be able to connect a full 2A worth of "other stuff" even with that hefty power supply, because the voltage regulator isn't rated for that sort of power. In such a case, the regulator will PROBABLY shut down gracefully (it's supposed to include over-voltage and over-temp shutdown) without suffering any permanent damage.

You COULD connect a 5V 2A supply on the OTHER side of the voltage regulator, in which case you could IN THEORY use all 2A on (for instance) a motor shield. This is effectively what happens when using USB with some computers; not all computers have the current limiting on the USB ports that they are supposed to. However, the pins used to connect shields aren't really rated for that sort of current...

Wow, what a detailed and thurough question rolls eyes

If you're talking about the 9v power supply, no it won't kill it, it means that you can pull UPTO 2A from the combined stuff connected to the Arduino(the board itself needs ~200)

If you want to run 2A off a output pin, DON'T it WILL KILL the pin and, your ATMEGA-164, or even the board itself. The MAX that each pin is rated for is 20MA(mil-amps)

If you want to provide a 2A INPUT on a pin, I'm not sure, but it could possibly fry the board. Depends on whether the board uses what it needs to trigger or all of it.

If you want to run 2A off the 5v output pin, I'm not sure, but the Voltage converter only supports ___ and you'd have to have a power supply rated at ~2.5-3

You can't get 2A off an output pin; the internal resistances inside the chip will prevent it. I suspect that you can short circuit Arduino output pins to GND (or +5V) for quite some time before you damage the chip irreparably, although doing so is outside of the specifications. MANY circuits of dubious merit connect LEDs directly to IO pins with no current limiting resistor, and those seem to run fine forever.

You can't push 2A input an input pin, because the input pins are CMOS gates, and draw effectively zero current (infinite resistance.) If you manage to measure ANY noticeable input current, that probably means the chip was already fried.

I SUSPECT that wjat the original poser meant was "can I connect a power supply rated at 2A to my Arduino." The answer to that is YES. However, you won't be able to connect a full 2A worth of "other stuff" even with that hefty power supply, because the voltage regulator isn't rated for that sort of power. In such a case, the regulator will PROBABLY shut down gracefully (it's supposed to include over-voltage and over-temp shutdown) without suffering any permanent damage.

You COULD connect a 5V 2A supply on the OTHER side of the voltage regulator, in which case you could IN THEORY use all 2A on (for instance) a motor shield. This is effectively what happens when using USB with some computers; not all computers have the current limiting on the USB ports that they are supposed to. However, the pins used to connect shields aren't really rated for that sort of current...

Third Post :/

Third Post :/

We seem to disagree on several subtleties, most notably what will happen when you try to draw 2A from an output pin...

Yours is a more detailed look at it.

As far as disagreeing, I didn;t go and look anything up to write that, I just remembered what people said before.

And what people said before was that you shouldn't connect a servo or the like to the output pin because the output pin would die, people also went on to mention that the max safe is 20ma. In a different post, someone mentioned that there's a fuse on each pin, so if you tried to pull more, it'd blow the pin.

Either way, It's agreed that you shouldn't plug 2A on an output pin simply because it'd kill it.

You state that the internals on the chip would prevent it I state that the fuse/chip would blow out.

Personally, I see my method as more logical because 2A through "internal resistance" on a MICROprocessor would kill it either way.

OK Thanks! ;)

HE LIVES!

So Jeff,

Where were you planning on pulling 2A from?

We spent all of a page and a half discussing all the possible places, the least you could do is state who's response helped the most (:P)

Hurrah for public forums.

I suspect that you can short circuit Arduino output pins to GND (or +5V) for quite some time before you damage the chip irreparably, although doing so is outside of the specifications. MANY circuits of dubious merit connect LEDs directly to IO pins with no current limiting resistor, and those seem to run fine forever.

err i had an output (analog output on high) and the two wires were pulled out of the testing breadboard and brushed eachother while in the air... for probably 1/100th of a second. My laptop powered off and i had to unplug it and remove the battery to get it to come back on.

lets just say output 9 doesn't work at all now... and i learned that sparkfun's ATMEGA168's aren't pre-programmed. ohh and to turn off the system while moving breadboards LOL =P

3 more pre programmed chips coming in the mail...

Had a similar problem, and it killed my keyboard (apple keyboards are usb hubs, and my arduino was connected to it)

I don't power Arduino from USB anymore ... and plug it on a cheap hub ^_^