So, a while ago, i accidentally connect 12 volt to my atmega 328p, at some pin of them, and my computer didn't detect it, can i just buy a new atmega328p or i need to buy new arduino
P.S im new to forum and i have a bad english
If your PC doesn't recognize the Arduino, it can be that the USB host controller is broken.
You can take the Atmega out of the socket and attach it to a "bare-bone" circuit on a breadboard. Now use a FTDI serial connection to check if the Arduino Atmega is still alive.
I would not trust anything on that board. If components did not die immediately, they can certainly be damaged and die at a later stage.
Buy a new one.
I agree with Leroy2007. If the PC doesn't recognize your Arduino the small 16U2 (for the USB connection) might be broken. The middle of the three pins in your picture is +5V, so if you hit that pin with 12V the chance of killing the USB chip and the Atmega328p at the same time is very high.
I think you'll need a new Arduino
Nope, that board is hosed.
If it doesn't detect on USB (assuming you know you have working drivers - the clones use different drivers than the official boards to), the serial adapter chip is dead - while the 328p is in the socket, the 16u2 on official boards (and the LM358 opamp used for the power supply switching and buffering the pin13 LED) is much easier to trash than the 328p.
The clones that use the CH340G instead of the 16u2 are generally harder to destroy; the 16u2 will blow if you look at it and imagine abusing the power rails, while CH340G boards rarely lose the serial adapter (the aforementioned opamp can still be blown easily though). Though exposing any arduino board to 12v (assuming no current limiting - 12v via, say, a 10k resistor or something to an I/O pin, should be okay; max through protection diode I think is 1mA, so 7/10,000 = 0.7 -> fine) is likely to trash any of them. The 328p is probably trashed too, anyway.
Like, whether you exposed the 5v rail or an I/O pin to 12v (in the case of the I/O pin, that would get onto the 5v rail via the protection diode, which in turn was what killed the 16u2), I can't imagine how that chip isn't totally dead.