Hi, my name luigi from italy. I'am study arduino and english language .. pin 12 .. Possible pin occupied?. Wasn't it the 13th???
Not sure of what you are asking. Most proto boards that look like yours do not have the power buses connected in the middle. Check to be sure they are.
Hi,
Please post your code.
Thanks.. Tom.. 
Powering a servo through the Arduino is a recipe for disaster.
What are the values of the current limiting resistors for the LEDs.
They can't be less than 470 ohm for an Uno R4. 1k would be better.
Leo..
Sketch Blank Upload
LED .. Insert from pin 12 .. with resistor 220 ohm.
Idea?
Thanks.
See post #6. Post your code!
code blank .. simple upload sketch blank,
void setup() {
// put your setup code here, to run once:
}
void loop() {
// put your main code here, to run repeatedly:
}
If I understood correctly, you asking why the led, connected to the pin 12, lit in half with a board, running an empty sketch?
If you interested in pin12 only, why did you connect all this stuff to the breadboard? remove all unused hardware and repeat the test.
I'm thinking somethings wrong with your wiring. With everything wired as you show, open the blink() sketch and modify the sketch to use pin 12 instead of 13. Download the sketch, and verify that the LED wired to pin 12 blinks as it should.
By the way, is that battery pack shown in your diagram real? By that I mean, do you have a a battery pack wired to the breadboard? How many cells in the pack, 4?
No-Comment, only LED .. with connect pin 12.
effects pin 13.. upload sketch blank onboard in the state sketch download.
Okay, the video doesn't play, and the text doesn't make sense.
Have a nice day, I'm out.
1 Like
Hi,
CAN YOU PLEASE POST THE CODE YOU HAVE LOADED INTO THE UNO?
If you have loaded a blank code sheet then the UNO will do nothing.
Tom..
ok, problem solved .. wrong wire and wrong ohm resistor. Thanks!.
Re open problem .. with solved Arduino Team Support via E-mail.
Response:
Hello,
Thanks for contacting Arduino Support.
We are aware of this issue or behavior since pin D12 is used for the SPI communication and is pulled up by default. However, if you declare this pin and set it to LOW the pin will stop having this behavior.
Hope you find this information. Let me know if you have any other queries.
Best regards,
Carlos A.
Arduino Support Team
reply :
This behavior is caused by a software definition, and it's because the pin is pulled up by default to enable the SPI communication.
So the only way to deactivate this behavior at the moment is to define the pin in the sketch and set its value to low. Be assured I will report this to the developers' team, so they can be aware of this behavior.
Please let me know if you have any other questions.
Carlos A.
_-------
@gigetto1982 Use the lastest board package core v1.0.4 to program the board, it should correct it. If not, contact Arduino Technical Support and ask for help with boatloader flasing to resolve pin 12 ( remains half lit] issue.