# Code help needed for relay shield for Halloween

**URL:** <https://community.particle.io/t/code-help-needed-for-relay-shield-for-halloween/15723>\
**Category:** General\
**Created:** [September 19, 2015, 12:37am UTC](https://community.particle.io/t/code-help-needed-for-relay-shield-for-halloween/15723 "2015-09-19T00:37:31Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![dura4570](https://avatars.discourse-cdn.com/v4/letter/d/cdc98d/32.png) [@dura4570](https://community.particle.io/u/dura4570)\
**Post date:** [September 19, 2015, 12:37am UTC](https://community.particle.io/t/code-help-needed-for-relay-shield-for-halloween/15723/1 "2015-09-19T00:37:31Z")

</div>

Well, it’s that time of year again… Halloween Prop building time! This years prop requires help with the code that will enable several boards to shake that are covering a window.

I have a photon in a v2 relay shield powering 2 separate 12VDC automotive door lock actuators. Each actuator is connected to 2 wooden boards. I flashed the Photon with one of the library relay shield programs to test it out, and it works fine. Now it needs a little coding magic that I cannot provide.

I ordered a motion sensor that is taking its sweet time getting here. I would like it to trigger a routine. I do not know if the trigger will be high or low as of right now.

Currently, the code turns all relays on and off continuously by a time I specify. I would like the actuators to alternate so that all boards aren’t shaking in unison. Additionally, there should be a time limit on the total runtime per triggering episode.

Any help would be greatly appreciated!

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<div class="post-metadata">

**Author:** ![kennethlimcp](https://avatars.discourse-cdn.com/v4/letter/k/c0e974/32.png) [@kennethlimcp](https://community.particle.io/u/kennethlimcp)\
**Post date:** [September 19, 2015, 12:56am UTC](https://community.particle.io/t/code-help-needed-for-relay-shield-for-halloween/15723/2 "2015-09-19T00:56:31Z")

</div>

Something like this?

```auto
if (triggered){
    for(uint8_t i = 3; i <= 7; i++ ){
        if(i != 7) digitalWrite(i,HIGH);
        if(i != 3) digitalWrite(i-1,LOW);
        delay(1000);
    }
}

```

Assuming you are using the default pins on the relay shield V2

This sure looks fun! 👻

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<div class="post-metadata">

**Author:** ![dura4570](https://avatars.discourse-cdn.com/v4/letter/d/cdc98d/32.png) [@dura4570](https://community.particle.io/u/dura4570)\
**Post date:** [September 19, 2015, 3:13am UTC](https://community.particle.io/t/code-help-needed-for-relay-shield-for-halloween/15723/3 "2015-09-19T03:13:24Z")

</div>

My apologies, I am not very well versed in code.

Is that for the motion sensor only?  
I am using the default Particle App “2-control-all-relays.ino”.

---

<div class="post-metadata">

**Author:** ![dura4570](https://avatars.discourse-cdn.com/v4/letter/d/cdc98d/32.png) [@dura4570](https://community.particle.io/u/dura4570)\
**Post date:** [October 12, 2015, 5:12pm UTC](https://community.particle.io/t/code-help-needed-for-relay-shield-for-halloween/15723/4 "2015-10-12T17:12:09Z")

</div>

I have modified some code that was written for me by harrisonhjones. It worked a week ago, now it is unpredictable. Can someone look at it and help me fix it?

```auto
int RELAY1 = D3;
int RELAY2 = D4;
int MOTION1 = D0;
 
unsigned long lastMotionTime = 0; 
int propDelay = 250; // In milliseconds(1/4 second)
int propOnTime = 10000; // In milliseconds(10 seconds)
int state = 0; // Normal operation = 0, Waiting to actuate prop in 1/4 second = 1, Actuating props for 10 seconds = 2
 
void setup()
{
    // Initilize the pins
    pinMode(RELAY1, OUTPUT);
    pinMode(RELAY2, OUTPUT);
    pinMode(MOTION1, INPUT);
    
    // Initialize all relays to an OFF state
    digitalWrite(RELAY1, LOW);
    digitalWrite(RELAY2, LOW);
    
    
    // Register two functions, one to allow for individual actuation of each relay and the other to test the effect
    Spark.function("relay", relayControl);
    Spark.function("test", test);
    
}
 
void loop()
{
    // In the normal "reset" state wait for a LOW signal on the motion detector. When that motion is seen record the time and go to the next state 
    if(state == 0)
    {
       if(digitalRead(MOTION1) == HIGH)
        {
            lastMotionTime = millis();
            state = 1;
        }
        else
        {
            // In the normal state the relays should not be ON"
            digitalWrite(RELAY1, LOW);
            digitalWrite(RELAY2, LOW);
            
        }
    }
    // Wait for 10 seconds then go to the next state
    else if(state == 1)
    {
        if((millis() - lastMotionTime) > propDelay)
        {
            state = 2;
        } 
    }
    // For the next 20 seconds bring the relays "ON". Once 20 seconds has passed go back to the normal or "rest" state
    else if(state == 2)
    {
        if((lastMotionTime + propOnTime) < millis())
        {
            state = 0;
        }
        else
        {
            digitalWrite(RELAY1, HIGH);
        delay(75);    
            digitalWrite(RELAY2, HIGH);
            
        }    
        delay(100);
        {
            digitalWrite(RELAY1, LOW);
        delay(200);
            digitalWrite(RELAY2, LOW);
            
        }    
        delay(75);
        {
            digitalWrite(RELAY1, HIGH);
        delay(400);    
            digitalWrite(RELAY2, HIGH);
            
        }   
        delay(100);
        {
            digitalWrite(RELAY1, LOW);
        delay(100);    
            digitalWrite(RELAY2, LOW);
            
        }
    }
    // Catch any mistakes and just go back to the normal state
    else
    {
        state = 0;
    }
    
}
 
int test(String command)
{
    // To test just simulate a low signal on the motion
    lastMotionTime = millis();
    state = 1;
}
 
// Taken from the relay example code in the SparkCore docs
// command format r1,HIGH
int relayControl(String command)
{
  int relayState = 0;
  // parse the relay number
  int relayNumber = command.charAt(1) - '0';
  // do a sanity check
  if (relayNumber < 1 || relayNumber > 3) return -1;
 
  // find out the state of the relay
  if (command.substring(3,7) == "HIGH") relayState = 1;
  else if (command.substring(3,6) == "LOW") relayState = 0;
  else return -1;
 
  // write to the appropriate relay
  digitalWrite(relayNumber-1, relayState);
  return 1;
}

```