LED Blink

Solving Approach

How do you plan to solve it? 
I use 250 ohm for the resistor and i can simply use the loop function to achieve your requirements
 
 

Code

#define GPIO your_gpio
void setup(){
pinMode(GPIO,OUTPUT);

digitalWrite(GPIO,0);

}

void loop(){

digitalWrite(GPIO,1);

delay(400);

digitalWrite(GPIO,0);

delay(800);

}

Output

Video

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Photo of Output

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