if ( digitalRead(. . .) == HIGH ) not triggering?

Projects Programming
1

Hi I'm trying to program a set of traffic lights but my if statement isn't working. I found how to use if digitalRead from here but it's probably taken out of context. All the variables and digitalWrites tod what they're supposed to do. I even asked my fellow classmates for help but they couldn't provide anything. I'm wondering if I have to rebuild everything or not.
Here's the arduino setup and code
I use Tinkercad's Arduino Uno R3 simulation so I don't know if this too could be a bug in the simulation.

EDIT: traffic lights not stop signs dumb me

620×757 81 KB 

//Variabelen van groepen leds
//groep1
int g1 = 11; //g = groen
int o1 = 12; //o = oranje
int r1 = 13; //r = rood
//groep2
int g2 = 8;
int o2 = 9;
int r2 = 10;
//groep3
int g3 = 5;
int o3 = 6;
int r3 = 7;



void setup()
{
  //Groep 1
  pinMode(g1, OUTPUT);	//Groen
  pinMode(o1, OUTPUT);	//Oranje
  pinMode(r1, OUTPUT);	//Rood
  
  //Groep 2
  pinMode(g2, OUTPUT);	//Groen
  pinMode(o2, OUTPUT);	//Oranje
  pinMode(r2, OUTPUT);	//Rood
  
  //Groep 3
  pinMode(g3, OUTPUT);	//Groen
  pinMode(o3, OUTPUT);	//Oranje
  pinMode(r3, OUTPUT);	//Rood
  
  
}


void loop()
{
  digitalWrite(r1, HIGH);
  delay(1000);
  digitalWrite(r1, LOW);
  delay(1000);
  
  digitalWrite(o1, HIGH);
  delay(1000); 
  digitalWrite(o1, LOW);
  delay(1000);
  
  digitalWrite(g1, HIGH);
  delay(1000); 
  digitalWrite(g1, LOW);
  delay(1000); 
  
 if( digitalRead(g1) == HIGH ){
  	digitalWrite(r2, HIGH);
  	digitalWrite(r3, HIGH);
 }
  
}
2 
  delay(1000);
  digitalWrite(g1, LOW);  //set g1 LOW
  delay(1000);
  if ( digitalRead(g1) == HIGH )  //test if g1 is HIGH
  {

Question : how could g1 be HIGH when you just set it LOW ?

3

The MicroController Execute the Program from top to bottom which means you have rewrite your code like this

digitalWrite(g1, HIGH);
delay(1000);
if( digitalRead(g1) == HIGH ){
digitalWrite(r2, HIGH);
digitalWrite(r3, HIGH);
}

digitalWrite(g1, LOW); //before setting (g1,LOW)
delay(1000);

}
then only your if statement will work.

4

then only your if statement will work.

But in this case you don’t need an if statement at all. So you can just remove it as it dose nothing.

5

Ah okay I understand now thank you guys a lot I didn't know that its behavior ran like a script, a massive oversight from my part
I did this and it works now as intended

 digitalWrite(g1, HIGH); 
  if( digitalRead(g1) == HIGH ){
  	digitalWrite(r2, HIGH);
  	digitalWrite(r3, HIGH);
    delay(1000);
  
  } 
  
  digitalWrite(g1, LOW); 
  if ( digitalRead(g1) == LOW ) {
    digitalWrite(r2, LOW);
  	digitalWrite(r3, LOW);
    delay(1000); 
  }
  
  digitalWrite(g1, LOW);

thanks again!

6 
digitalWrite(g1, HIGH); 
  if( digitalRead(g1) == HIGH ){

Again, you just set it HIGH.
How is it going to be anything but HIGH?

7

How is it going to be anything but HIGH?

Precisely.

Why do you think you need an 'if' statement? You already know the logic level on that pin.

I didn't know that its behavior ran like a script

As a point of interest how did you think it ran?