Arduino uno overheating

Question

I tried to get digital reading on my arduino uno board to check if 5V signal is on or off. When I plugged it in digital pin 9 it got really hot really fast. Also it couldn't give me correct readings on A0 analog input. Later it worked fine on digital pin 8. I know that pin 9 can be used to provide PWM output but i thought that they can also be used as regular digital input pins. How can I use this pin as digital input?

This might get better attention on the SuperUser forum. – Lizz Oct 15 '13 at 05:54 — Lizz, Oct 15 '13 at 05:54

score 1 · Answer 1 · answered Dec 13 '13 at 23:36

On reset, all pins is set as INPUT (ref: http://arduino.cc/en/Tutorial/DigitalPins), no need to explicitly set it to INPUT mode.

If something get abnormally hot, it's indication that something is wrong with your circuit (i.e., you should put a limiting resistor, or you put it on wrong polarity, etc.)

score 0 · Answer 2 · answered Oct 15 '13 at 07:56

0

void setup(){
     pinMode(9, INPUT);
}

answered Oct 15 '13 at 07:56

ladislas

3,037
19
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score 0 · Answer 3 · answered Dec 01 '13 at 19:00

When using the input pins you have to use three pins. You have to use a ground pin, an analog pin, and a 5V to 3.3V power source. If you are using a switch, button, potentiometer, etc, this is what you have to state:

int slideSwitch

void setup() {
pinMode(slideSwitch, INPUT);
}

void loop() {
}               // your program

I suggest using buttons and switches from http://www.qtechknow.com/

JUST REMEMBER TO US A GROUND, ANALOG PIN, AND A POWER FROM 3.3V to 5V.

Arduino uno overheating

3 Answers3