How to get my program to function properly.

Projects Programming
1

What i'm trying to have my program do is check to see if my switch is triggered (Pin 4)
and then trigger my relay to do half a second on half a second off in a loop.

void setup() {
  // put your setup code here, to run once:
  pinMode(2,OUTPUT);
  pinMode(4,INPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
if (digitalRead(4) == HIGH) {
  digitalWrite(2,HIGH);
  delay(500);
  digitalWrite(2,LOW);
  delay(500);
}
}

Currently it isn't doing this and isn't checking on my switch. Any help is appreciated.

2

How is the switch and relay wired?

3

aarg:
How is the switch wired?

I have 5v running through it to pin 4

4

donnyk:
I have 5v running through it to pin 4

That's not enough. You need also a pull down resistor on pin 4.

5

Typical switch wiring for Arduino

2017-08-05_20-33-24.jpg
2017-08-05_20-33-24.jpg1004×939 224 KB

2017-08-05_20-33-24.jpg
2017-08-05_20-33-24.jpg1004×939 224 KB

6

aarg:
That's not enough. You need also a pull down resistor on pin 4.

I'm somewhat new to Arduino, how would I wire that in?

7

donnyk:
I'm somewhat new to Arduino, how would I wire that in?

Honestly, you are better off using INPUT_PULLUP and inverting your logic:

void setup() {
  // put your setup code here, to run once:
  pinMode(2,OUTPUT);
  pinMode(4,INPUT_PULLUP);
}

void loop() {
  // put your main code here, to run repeatedly:
if (digitalRead(4) == LOW) {
  digitalWrite(2,HIGH);
  delay(500);
  digitalWrite(2,LOW);
  delay(500);
}
}

Like S3 in reply#4

8

aarg:
Like S3 in reply#4

I'm still a bit confused by the diagram- Do I connect the resistor to 5v and then to pin 4?

EDIT: Oh nevermind, I've figured it out. I forgot that my relay is wired so that it outputs Ground instead of 5v, so I had to switch my resistor+switch to Ground instead of 5v