Help with 4 way relay code

Projects General Guidance
1

Hello there I'm looking for some help to get relay 4 to turn on 4 secs after the first 3 have turned. I scoured the internet to try and figure it out but not getting anywhere. Here's the code I'm using.

int relay_1 = 4;
int relay_2 = 7;
int relay_3 = 8;
int relay_4 = 12;

void setup() {
// put your setup code here, to run once:
Serial.begin(9600);

pinMode(relay_1, OUTPUT);
pinMode(relay_2, OUTPUT);
pinMode(relay_3, OUTPUT);
pinMode(relay_4, OUTPUT);

}

void loop() {

digitalWrite(relay_1, HIGH);
digitalWrite(relay_2, HIGH);
digitalWrite(relay_3, HIGH);
digitalWrite(relay_4, HIGH);

Serial.println("All relays ON");

delay(10000);

digitalWrite(relay_1, LOW);
digitalWrite(relay_2, LOW);
digitalWrite(relay_3, LOW);
digitalWrite(relay_4, LOW);

Serial.println("All relays OFF");

delay(10000);
}

2

Take some time and describe the desired function of the sketch in simple words and this very simple.

3

How to properly post code using code tags.

int relay_1 = 4;
int relay_2 = 7;
int relay_3 = 8;
int relay_4 = 12;

void setup() {
// put your setup code here, to run once:
Serial.begin(9600);

pinMode(relay_1, OUTPUT);
pinMode(relay_2, OUTPUT);
pinMode(relay_3, OUTPUT);
pinMode(relay_4, OUTPUT);

}

void loop() {

digitalWrite(relay_1, HIGH);
digitalWrite(relay_2, HIGH);
digitalWrite(relay_3, HIGH);
digitalWrite(relay_4, HIGH);

Serial.println("All relays ON");

delay(10000);

digitalWrite(relay_1, LOW);
digitalWrite(relay_2, LOW);
digitalWrite(relay_3, LOW);
digitalWrite(relay_4, LOW);

Serial.println("All relays OFF");

delay(10000);
}

You are welcome.

4 
int relay_1 = 4;
int relay_2 = 7;
int relay_3 = 8;
int relay_4 = 12;

void setup() {
// put your setup code here, to run once:
Serial.begin(9600);

pinMode(relay_1, OUTPUT);
pinMode(relay_2, OUTPUT);
pinMode(relay_3, OUTPUT);
pinMode(relay_4, OUTPUT);

}

void loop() {

digitalWrite(relay_1, HIGH);
digitalWrite(relay_2, HIGH);
digitalWrite(relay_3, HIGH);

delay(4000); <<<<<<<<<<<<<<<<<<<<<<<<<<<<add a 4 second delay
digitalWrite(relay_4, HIGH);

Serial.println("All relays ON");

delay(10000); might want to change this to 6000

digitalWrite(relay_1, LOW);
digitalWrite(relay_2, LOW);
digitalWrite(relay_3, LOW);
digitalWrite(relay_4, LOW);

Serial.println("All relays OFF");

delay(10000);
}

add a delay before turning on relay # 4

5

Thank you! I've tried adding a delay like this but it turns off the other relays. I want the first 3 to turn on, stay on and then relay 4 to turn on 4 secs later and then all turn off together. So relay 1,2,3 on, for secs later relay 4 turns on. 10 secs in total 5hen all turn off. I'm new to this if you hadn't guessed. But thanks for replying so quickly

6

Show us your attempt.

7

What´s the task of sketch?

8

Try this:

#include <Arduino.h>

#define NUM_RELAYS 4
#define INTERVAL 5 // Time in seconds
#define DELAY_INTERVAL 4 // Time in seconds
const byte relayPin[NUM_RELAYS] = {4, 7, 8, 12};

bool currentStatus[NUM_RELAYS] = {false};
unsigned long prevMillis = 0;
unsigned long delayMillis = 0;

byte relaysChanged = 0;

void setup()
{
  Serial.begin(9600);

  for (byte i = 0; i < NUM_RELAYS; i++)
  {
    pinMode(relayPin[i], OUTPUT);

    digitalWrite(relayPin[i], currentStatus[i]);
    Serial.print("Relay ");
    Serial.print(i);
    Serial.println(currentStatus[i] ? ": ON" : ": OFF");
  }
  Serial.println();
  prevMillis = millis();
}

void loop()
{
  if ((millis() - prevMillis) >= (INTERVAL * 1000UL))
  {
    for (byte i = 0; i < NUM_RELAYS; i++)
    {
      if (i != (NUM_RELAYS - 1))
      {
        currentStatus[i] = !currentStatus[i];
        digitalWrite(relayPin[i], currentStatus[i]);
        if (currentStatus[i] == true)
        {
          relaysChanged++;
        }
        Serial.print("Relay ");
        Serial.print(i);
        Serial.println(currentStatus[i] ? ": ON" : ": OFF");
      }
    }

    if (relaysChanged == 0)
    {
      currentStatus[NUM_RELAYS - 1] = false;
      digitalWrite(relayPin[NUM_RELAYS - 1], currentStatus[NUM_RELAYS - 1]);

      Serial.print("Relay ");
      Serial.print(NUM_RELAYS - 1);
      Serial.println(": OFF\n");
    }
    prevMillis = millis();
    delayMillis = millis();
  }

  if (relaysChanged == (NUM_RELAYS - 1))
  {
    if ((millis() - delayMillis) >= (DELAY_INTERVAL * 1000UL))
    {
      currentStatus[NUM_RELAYS - 1] = true;
      digitalWrite(relayPin[NUM_RELAYS - 1], currentStatus[NUM_RELAYS - 1]);

      Serial.print("Relay ");
      Serial.print(NUM_RELAYS - 1);
      Serial.println(": ON\n");
      relaysChanged = 0;
    }
  }
}
2 Likes
9

Hi @blackheart69,

there seems to be something wrong with your hardware if the three relays switch off during a delay.

As @LarryD already mentioned a description of your hardware setup would be more than helpful.

Whether delays() are a reasonable solution to your task can only be evaluated if you would describe the objective of your application ...

Regards
ec2021

P.S.: @FernandoGarcia has already posted a generally better solution ... But if the relays change state during a delay there seems to be some other trouble ...

1 Like
10

Thank you that's great I will try it next week when back at work and we share the update with you.thanks again

11

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