I'm attempting to make a 12v blinking light that turns off with a high signal and since I've got some 5v arduino pro minis I though I might do it with them. So I put together a program and a plan
My idea was, that when the switch is closed, 3-4.6v is applied to pin 3 (logic level high) and my program stops the blinking. Testing this with 5v without a voltage divider just pulling pin 3 high or low seemed to work. So I hooked up the voltage divider and tested it with a 12V-14V source. All seemed well until I connected the voltage divider (R1) to 12V (while monitoring the voltage it was outputting) even though I saw only 3V on pin 3 the micro-controller went pop. I'm not really sure why it popped, sorry if this is a stupid question but I'm not the best at this stuff. Any help is appreciated, thanks.
Edit: Genuine question, why do some of my questions get voted down? Am I using this site wrong or formatting my questions wrong? I've been trying to learn electronics, but so far this site hasn't been of much help. I don't really understand why some people vote down questions without telling the asker what they are doing wrong. If you could explain what they're doing wrong it can help them to not make the same mistake in the future (E.g. formatting wrong, not site applicable etc).