LED does not completely turn on

Development Tools IDE 1.x
1

Hi, does anyone know why my led is not turning on completely.
One month ago, with the same circuit, the LED turned on just fine, but now that i am trying to do it again, i barely see the light.
Or is a malfunction of the ARduino ??

2

No.
Probably not - who knows?

3

(deleted)

4

Yes, sorry.

int led=7;

void setup() {
pinMode(led,OUTPUT);
Serial.begin(9600);
digitalWrite(led,HIGH);
delay(500);
digitalWrite(led,LOW);

}

void loop() {
int LDR=analogRead(A0);
Serial.println(LDR);
if(LDR<100)
{
  digitalWrite(led,HIGH);
}
if(LDR>100)
{
  digitalWrite(led,LOW);
}
}
5

Depends on what that "LED does not completely turn on" means.
Does it emit a dim light?

Does it blink right when the sketch is starting?
If it does not, you probably have something wrong with a LED. It is burnt out? The current limiting resistor is cracked or any other extra resistance in the chain? Some cold soldering?

If the LED flashes right on a start and gets dim after, maybe your LDR is fluctuating near 100 and LED goes on and off producing kinda PWM signal?

What is the serial monitor telling you?

6

Have you tried the led and its resistor across the Arduino 5V output (ie, not an i/o pin) and ground?

7

I have changed the resistor and the LED and everything remains the same.
No, since the beggining, the LED blink but really low and stays that way.
I tried the same with a different arduino and all went well, i think the arduino is not giving the enough current or something like that??

8

What is the value of your resistor? is the LED a 'normal' one or is it a 5v or 12v specific.
What is the output of the LED\resistor when connected across 5V and ground? how bright is it?