Struggling to get my UNO and MEGA to talk to each other properly (digitalWrite(LOW))

[milklizard88]

Hi. I'm going to post unabriged code and wiring diagrams at the bottom of the post, I've had to take apart my UNO and start putting it back together one pin at a time to claw back functionality, so I might post a scaled back diagram and abriged code to explain where I think the problem is, but the full story will be at the bottom of this post.

I have a setup to control an escape room, there's probably a million better ways to do this, but I'm amateur so I'd appreciate the help. My setup is made of three parts;

• An arduino MEGA, controlling most aspects of the room. Lights, doors, relays etc.
• An UNO, specifically for scares, lights and horror sounds
• A couple of esps, controlling keypads, LCDs and an ultrasound distance sensor.

The uno and mega are connected to a "scare switch" about 10m down the corridor that basically blocks anything spooky in case my customers don't want to be scared. Currently both boards are reacting properly to this switch (for once, haha).

The esps are communicating properly with the mega when I send the following low 600ms 'pulse'

      digitalWrite (successPin, LOW); // Tell mega to initiate firstCams
      digitalWrite (buzzPin, HIGH);
      digitalWrite (lockPin, LOW);
      delay (600);
      digitalWrite (successPin, HIGH);
      digitalWrite (buzzPin, LOW);
      digitalWrite (lockPin, HIGH);

But then I send a similar low signal from the mega to the uno;

  if(circsqtriSwitch.fell())
  {
    Serial.println("1612 complete");
    digitalWrite(circsqtriSig, LOW); // Tell the scare uno that 1612 has been input
    firstcams();
  }

This signal doesn't get picked up by the uno (here's the code that's looking out for it);

  circsqtriSwitch.update();

  if(circsqtriSwitch.fell())
  {
    Serial.println("1612 complete");
    violentAttack();
  }

Here's an abriged diagram of how it looks

I'm thinking it has something to do with ground reference, like, the mega pin (pin A15 is already at ground, therefore digitalWrite(LOW) doesn't cause the pin to "fall" and trigger the violentAttack()

As per the diagram I've connected the grounds together (they're actually connected via the scare switch ground pin but I guess it's all the same).

It works when I disconnect the cable from the UNO pin A0, then short the pin to ground. Doing this triggers violentAttack() (the same is true for pin A1 and A3) a la this diagram;

Interestingly, this doesn't work when the pin is connected to the mega (I.e. UNO A0 connected to MEGA A15) which is why I think the pin isn't "falling" when the puzzle is completed and the pulse is sent, it only works if the pin is disconnected.

I initially solved it by writing the 3 mega pins high in setup, then they worked. The problem is it caused some funny business with the UNO, in particular when I disconnected Vin and gnd from the UNO, it was still powered through these pins that were getting this high signal. I'm not an expert but I'd imagine powering the UNO through the logic pins was a bad idea, so I turned this part of the code off.

  pinMode (circsqtriSig, OUTPUT);
  // digitalWrite (circsqtriSig, HIGH);
  pinMode (reedSig, OUTPUT);
  // digitalWrite (reedSig, HIGH);
  pinMode (doorSig, OUTPUT);
  // digitalWrite (doorSig, HIGH);

So this is why I've come to the forum. I'd imagine there's a million ways to do this better, I'm currently looking into learning espNOW to controll all the microcontrollers wirelessly but for now I kinda need to get the experience reopened so if anyone had an easy fix for now, then suggested I look into a better implementation (i've heard of something called UART?) then I'm all ears.

Is there a way to write the three pins (A0, 1 and 3) as "floating", neither HIGH or LOW?

Should I use the non- analog pins? (actually, my spidey sense is telling me this might be the problem, I'll try changing the pins, and update today)

Thank you in advance!

UNO code

// Scare control UNO

#include <AltSoftSerial.h> // Alt serial library, see library folder in dropbox
#include <Wire.h>
#include <MD_YX5300.h> // See library folder in dropbox
#include <Bounce2.h> // For debouncing button input. See https://github.com/thomasfredericks/Bounce2

// Tunable variables - These are so you can sync up sounds and scares easily

int FHdim = 1500; // Time for the spotlight to dim after the MP3 has been triggered
int FHrelay = 1500; // Time for relay to hit 
int BYdelay1 = 5000; // Time for first behind you after reed trigger
int BYdelay2 = 5000; // Time for second behind you after first behind you
int BYflicker1 = 5000; // Time for first flicker pulse
int BYflicker2 = 5000; // Time for second flicker pulse
int fadeAmount = 5;  // how many points to fade the spotlight by
int fadeinTime = 50; // how quickly to fade the spotlight up (this is slower)
int fadeoutTime = 20; // how quickly to fade the spotlight up (this is quick)

// Input pins

int hiss = 12;
int hissSelect; // Random number to select which hiss mp3 to select
int flicker = 6;
int exhale = 10;
int baby = 11;


// Output pins

int megaFlicker = A5;
int megavolumeDown = 2;

// Input triggers

int circsqtriPin = A0; // Trigger for 1612 and starts violet attack countdown
int rfidPin = A1; // Trigger the facehugger sequence 
int jump7Pin= A2; // Trigger the window opening sounds
int reedPin = A3; // Trigger any behind you sequence
int plugPin = A4; // Trigger the scare
int ultrasoundPin = 7;

// Pins for scare switch
int scareSwitch = 13; // This is pulled low when scares are being turned on.
int switchState; // 

// Utility

int spotlight = 5; // PWM pin to control the brightness of the light (via MOSFET)
int brightness = 0;  // how bright the spotlight is
int lightRelay = 3; // Relay attached to light NO is floor NC is hand
int facehuggerRelay = 4; // Relay to release the facehugger scare

bool plugState = false; // Keeps the "waiting for plug" loop going

// GLOBALS

// Create an array of Bounce objects for each input button

Bounce circsqtriSwitch = Bounce();
Bounce reedSwitch = Bounce();
Bounce rfidSwitch = Bounce();
Bounce jump7Switch = Bounce();
Bounce plugSwitch = Bounce();
Bounce ultrasoundSwitch = Bounce();

Bounce hissSwitch = Bounce();
Bounce exhaleSwitch = Bounce();
Bounce babySwitch = Bounce();
Bounce flickerSwitch = Bounce();

// Initialise a software serial interface on the approriate Rx/Tx pins (8/9)
AltSoftSerial altSerial;
// And create an MP3 object based on the serial connection
MD_YX5300 mp3(altSerial);

void setup() 
{
  delay (10000);
  
  // Initialise a serial connection (used for debugging only)
  Serial.begin(115200);
  Serial.println(__FILE__ __DATE__);
  Serial.println("Serial connection initialised");

  Serial.println ("Setup 2 begun, buffer initiated");
  delay (10000);
  Serial.println ("Buffer 2 complete");

  reedSwitch.attach(reedPin, INPUT_PULLUP);
  rfidSwitch.attach(rfidPin, INPUT_PULLUP);
  circsqtriSwitch.attach(circsqtriPin, INPUT_PULLUP);
  jump7Switch.attach(jump7Pin, INPUT_PULLUP);
  plugSwitch.attach(plugPin, INPUT_PULLUP);
  ultrasoundSwitch.attach(ultrasoundPin, INPUT_PULLUP);

  hissSwitch.attach(hiss, INPUT_PULLUP);
  flickerSwitch.attach(flicker, INPUT_PULLUP);
  exhaleSwitch.attach(exhale, INPUT_PULLUP);
  babySwitch.attach(baby, INPUT_PULLUP);

  Serial.println("Utility buttons initialised");

  // Scare mode?
  pinMode (scareSwitch, INPUT_PULLUP);
  switchState = digitalRead(scareSwitch);
  Serial.println(switchState);
  
  // Initialise pins and test

  pinMode(megaFlicker, OUTPUT);
  pinMode(megavolumeDown, OUTPUT);

  pinMode(spotlight, OUTPUT);
  pinMode(facehuggerRelay, OUTPUT);
  digitalWrite(facehuggerRelay, LOW);
  pinMode(lightRelay, OUTPUT);
  digitalWrite (lightRelay, LOW);

  // Test

  // Initialise the serial interface to the MP3 player
  altSerial.begin(9600);
  mp3.begin();
  mp3.volume(30);
  delay(1000);

  if (switchState == 0){
    Serial.print(switchState);
    mp3.playTrack(1); // "Horror mode is turned on"
    Serial.println ("Horror mode is turned ON");
  
  }
  else {
    Serial.print(switchState);
    mp3.playTrack(2); // "Horror mode is turned off"
    Serial.println ("Horror mode is turned OFF");
  }

  delay(1000);
  Serial.println("Setup complete");
}

void loop() 
{
  switchState = digitalRead(scareSwitch);
  // Serial.print(switchState);
  
  if (switchState == 0){
    // Serial.println("SPOOKY");
  }
  else {
    Serial.println("Safe");
  }

  reedSwitch.update();
  rfidSwitch.update();
  circsqtriSwitch.update();
  jump7Switch.update();

  hissSwitch.update();
  flickerSwitch.update();
  exhaleSwitch.update();
  babySwitch.update();


  if(circsqtriSwitch.fell())
  {
    Serial.println("1612 complete");
    violentAttack();
  }

  if(rfidSwitch.fell())
  {
    Serial.println("rfid complete");

    //Todo light relay change

    if (switchState == 0)
    {
      Serial.println("SCARES ARE ON");
      jumpScare();
    }
    else
    {
      Serial.println("SCARES ARE OFF");
      noScare();
    }
  }

  if(jump7Switch.fell())
  {
    Serial.println("jump7 complete");
    cryBabies();
  }

  if(reedSwitch.fell())
  {
    Serial.println("reed complete");
    
    behindYou();

  }

  if(flickerSwitch.fell())
  {
    Serial.println("flicker");
    {
      sendFlicker();
    }
  }

  if(babySwitch.fell())
  {
    Serial.println("baby");
    
    if (switchState == 0)

    {
      mp3.playTrack(10);
    }
  }

  if(hissSwitch.fell())
  {
    Serial.println("hiss");
    if (switchState == 1)
    {
      whataHisser();
    }
  }

  if(exhaleSwitch.fell())
  {
    Serial.println("exhale");
    
    if (switchState == 1)
    {
      mp3.playTrack(11);
    }
  }
}

void violentAttack()
{
  Serial.println("in function violentAttack");

  if (switchState == 0)
  {
    Serial.println("playing violent attack");
    delay(45000);
    mp3.playTrack(3);
  }
  return;
}

void jumpScare() // TO DO
{
  Serial.println("in jumpScare");
  digitalWrite(lightRelay, HIGH);   
  mp3.playTrack(7);
  int ultrasoundPinging = true;

  do
  {
    plugSwitch.update();
    ultrasoundSwitch.update();

    if(ultrasoundSwitch.fell())
    {
      mp3.playTrack(5); // Facehugger cry
      ultrasoundPinging = false; // Cease this IF statement in future
      spotlightOn(); // Turn on spotlight

      digitalWrite(megavolumeDown, LOW); // Send volume down signal
      delay(200);
      digitalWrite(megavolumeDown, HIGH);
    }

    if(plugSwitch.fell())
    {
      Serial.println("plug connected");
      mp3.playTrack(9);
      delay(FHdim);
      spotlightOff();
      delay(FHrelay);
      digitalWrite (facehuggerRelay, HIGH);
      delay(200);
      digitalWrite(facehuggerRelay, LOW);
      plugState = true;
      delay(2000);
      digitalWrite(lightRelay, LOW);
      
      
      digitalWrite(megavolumeDown, LOW); // Send volume up signal
      delay(200);
      digitalWrite(megavolumeDown, HIGH);    
    }
  }
  while (plugState == false);
}

void noScare()
{
  Serial.println ("in noScare");
  mp3.playTrack(8);
  return;
}

void cryBabies ()
{
  if (switchState == 0)
  {
    delay(10000);
    mp3.playTrack(5);
    delay(60000);
    mp3.playTrack(4);
  }

  else
  {
    return;
  }
}

void behindYou()
{
  switchState = digitalRead(scareSwitch);
  Serial.println(switchState);

  if(switchState == 0)
  {
    delay (BYdelay1);
    mp3.playTrack(12);
    delay (BYdelay2);
    sendFlicker();
    delay (BYflicker1);
    mp3.playTrack(13);
    delay (BYflicker2);
    sendFlicker();
  }
  else
  {
    return;
  }
}

void spotlightOn()
{
    brightness = 0;
  do 
  {
    analogWrite(spotlight, brightness); // Set current brightness
    // Serial.println (brightness);
    brightness = brightness + fadeAmount; // Increase brightness
    delay(fadeinTime);
  }
  while (brightness <= 225); // Till brightness maxed

  analogWrite(spotlight,225);

  return; 
}

void spotlightOff()
{
  do 
  {
    analogWrite(spotlight, brightness); // Set current brightness
    // Serial.println (brightness);
    brightness = brightness - fadeAmount; // Decrease brightness
    delay(fadeoutTime);

  }
  while (brightness >= 0); // Till brightness at minimum

  analogWrite(spotlight, 0); 
  return; 
}

void whataHisser()
{
  hissSelect = random(3);
  Serial.println (hissSelect);

  if (hissSelect == 0)
  {
    mp3.playTrack(14);
  }
  else if (hissSelect == 1)
  {
    mp3.playTrack(15);
  }
  else if (hissSelect == 2)
  {
    mp3.playTrack(16);
  }
}

void sendFlicker()
{
  if (switchState == 0)
  {
    digitalWrite(megaFlicker, LOW);
    delay(200);
    digitalWrite(megaFlicker, HIGH);
    mp3.playTrack(18);
  }
}

UNO diagram

MEGA code

// DSB mega brain

#include <AltSoftSerial.h> // Alt serial library, see library folder in dropbox
#include <Wire.h>
#include <MD_YX5300.h> // See library folder in dropbox
#include <Bounce2.h> // For debouncing button input. See https://github.com/thomasfredericks/Bounce2

// Cam relay pins
int cam[8] = {2,3,4,5,6,7,8,9}; 

// Tunable variables - These are so you can sync up sounds and scares easily

int NSmp3 = 1500; // Delay for door voice over for scare free
int JSmp3 = 1500; // Delay for door voice over for jump scare
int vol = 30; // Variable to control the volume of ambient music
int volInterval = 1; // Variable to control the speed of volUp and volDown
bool lightsOn; // Bool to keep track of the lights status
bool jumpScare; // Bool to keep us in the jumpScare do while loop
int FHstrike = 5000; // Time to wait to turn on lights after facehugger has struck

int intMax = 300; // Random max interval (Decrease if flicker is taking too long)
int intMin = 50; // Random min interval (Increase if flicker is too snappy)

int BYflicker2 = 5000; // Time for second flicker pulse
int fadeAmount = 5;  // how many points to fade the spotlight by
int fadeinTime = 50; // how quickly to fade the spotlight up (this is slower)
int fadeoutTime = 20; // how quickly to fade the spotlight up (this is quick)
int distanceThreshold = 700; // how close player has to be to distance sensor

// Pins leds

int r1 = 30;
int g1 = 31;
int r2 = 32;
int g2 = 33;
int r3 = 34;
int g3 = 35;
int r4 = 36;
int g4 = 37;
int r5 = 38;
int g5 = 39;
int r6 = 40;
int g6 = 41;
int r7 = 42;
int g7 = 43;
int r8 = 44;
int g8 = 45;

// Reed pins

int wReed = A1;
int reedPin = A0;
int rReed = A3;
int gReed = A2;

// Scare stuff

int circsqtriSig = A15; // UNO pin A0
int doorSig = A14;      // UNO pin A1
int reedSig = A13;      // UNO pin A3



// Success triggers

int circsqtriPin = A8;
int rfidPin = A7;
int flickerPin= A12;
int volUpPin = A10; // Connected to UNO 0
int volDownPin = A11; // Connected to UNO 1

// Pins for scare switch
int scareSwitch = A9;
int switchState;

// Utility pins
int buzzPin = 53;

int relay1 = 21; 
int relay2 = 20; // Door NO is bolt engaged
int relay3 = 19; // Rotato potato NC is lights, NO is maglock
int strip1 = 18; 
int strip2 = 17;
int strip3 = 16;
int strip4 = 15;
int strip5 = 14;



// GLOBALS

// Create an array of Bounce objects for each input button
Bounce circsqtriSwitch = Bounce();
Bounce reedSwitch = Bounce();
Bounce rfidSwitch = Bounce();
Bounce flickerSwitch = Bounce();
Bounce volDownSwitch = Bounce();
Bounce volUpSwitch = Bounce();

// Initialise a software serial interface on the approriate Rx/Tx pins (8/9)
AltSoftSerial altSerial;
// And create an MP3 object based on the serial connection
MD_YX5300 mp3(altSerial);

void setup() 
{
  // Initialise a serial connection (used for debugging only)
  Serial.begin(115200);
  Serial.println(__FILE__ __DATE__);
  Serial.println("Serial connection initialised");

  
  reedSwitch.attach(reedPin, INPUT_PULLUP);
  rfidSwitch.attach(rfidPin, INPUT_PULLUP);
  circsqtriSwitch.attach(circsqtriPin, INPUT_PULLUP);
  flickerSwitch.attach(flickerPin, INPUT_PULLUP);
  volUpSwitch.attach(volUpPin, INPUT_PULLUP);
  volDownSwitch.attach(volDownPin, INPUT_PULLUP);
  Serial.println("Utility buttons initialised");

  // Initialise led pins and test
  pinMode (buzzPin, OUTPUT);

  pinMode (scareSwitch, INPUT_PULLUP);

  pinMode (r1, OUTPUT);
  pinMode (r2, OUTPUT);
  pinMode (r3, OUTPUT);
  pinMode (r4, OUTPUT);
  pinMode (r5, OUTPUT);
  pinMode (r6, OUTPUT);
  pinMode (r7, OUTPUT);
  pinMode (r8, OUTPUT);

  pinMode (g1, OUTPUT);
  pinMode (g2, OUTPUT);
  pinMode (g3, OUTPUT);
  pinMode (g4, OUTPUT);
  pinMode (g5, OUTPUT);
  pinMode (g6, OUTPUT);
  pinMode (g7, OUTPUT);
  pinMode (g8, OUTPUT);

  pinMode (rReed, OUTPUT);
  pinMode (gReed, OUTPUT);
  pinMode (wReed, OUTPUT);

  pinMode (circsqtriSig, OUTPUT);
  // digitalWrite (circsqtriSig, HIGH);
  pinMode (reedSig, OUTPUT);
  // digitalWrite (reedSig, HIGH);
  pinMode (doorSig, OUTPUT);
  // digitalWrite (doorSig, HIGH);


  // Test

  

  digitalWrite (buzzPin, HIGH);
  delay(200);
  digitalWrite (buzzPin, LOW);

  digitalWrite (g1, HIGH);
  delay(100);
  digitalWrite (g2, HIGH);
  delay(100);
  digitalWrite (g3, HIGH);
  delay(100);
  digitalWrite (g4, HIGH);
  delay(100);
  digitalWrite (g5, HIGH);
  delay(100);
  digitalWrite (g6, HIGH);
  delay(100);
  digitalWrite (g7, HIGH);
  delay(100);
  digitalWrite (g8, HIGH);
  delay(100);

  digitalWrite (buzzPin, HIGH);
  delay(200);
  digitalWrite (buzzPin, LOW);

  digitalWrite (g1, LOW);
  delay(100);
  digitalWrite (g2, LOW);
  delay(100);
  digitalWrite (g3, LOW);
  delay(100);
  digitalWrite (g4, LOW);
  delay(100);
  digitalWrite (g5, LOW);
  delay(100);
  digitalWrite (g6, LOW);
  delay(100);
  digitalWrite (g7, LOW);
  delay(100);
  digitalWrite (g8, LOW);
  delay(100);

  digitalWrite (buzzPin, HIGH);
  delay(200);
  digitalWrite (buzzPin, LOW);

  digitalWrite (r1, HIGH);
  delay(100);
  digitalWrite (r2, HIGH);
  delay(100);
  digitalWrite (r3, HIGH);
  delay(100);
  digitalWrite (r4, HIGH);
  delay(100);
  digitalWrite (r5, HIGH);
  delay(100);
  digitalWrite (r6, HIGH);
  delay(100);
  digitalWrite (r7, HIGH);
  delay(100);
  digitalWrite (r8, HIGH);
  delay(100);

  digitalWrite (buzzPin, HIGH);
  delay(200);
  digitalWrite (buzzPin, LOW);

  // Initialise cam pins and set them low

  for(int i=0; i<8; i++)
  {
    pinMode (cam[i], OUTPUT);
    digitalWrite (cam[i], LOW); // Set all pins low to turn the relays on (and turn the cameras off)
    delay(100);
  }

  // Initiate secondary relays

  pinMode(relay1, OUTPUT);
  pinMode(relay2, OUTPUT);
  digitalWrite(relay2, LOW); // Engage bolt
  pinMode(relay3, OUTPUT);
  digitalWrite(relay3, LOW); // Engage maglock
  pinMode(strip1, OUTPUT);
  pinMode(strip2, OUTPUT);
  pinMode(strip3, OUTPUT);
  pinMode(strip4, OUTPUT);
  pinMode(strip5, OUTPUT);
  
  // Test reed box
  digitalWrite (rReed, HIGH);
  delay(200);
  digitalWrite (buzzPin, HIGH);
  delay(200);
  digitalWrite (buzzPin, LOW);
  digitalWrite (rReed, LOW);
  delay(200);
  digitalWrite (gReed, HIGH);
  delay(200);
  digitalWrite (buzzPin, HIGH);
  delay(200);
  digitalWrite (buzzPin, LOW);
  digitalWrite (gReed, LOW);
  delay(200);
  digitalWrite (wReed, HIGH);
  delay(200);
  digitalWrite (buzzPin, HIGH);
  delay(200);
  digitalWrite (buzzPin, LOW);
  delay(200);

  Serial.println("Cams initialised");

  // Initialise the serial interface to the MP3 player
  altSerial.begin(9600);
  mp3.begin();
  mp3.volume(vol);

  switchState = digitalRead(scareSwitch);

  if (switchState == 0) // Scares are on
  {
    mp3.playTrack(2);
    digitalWrite(strip1,LOW);
    digitalWrite(strip2,LOW);
    digitalWrite(strip3,LOW);
    digitalWrite(strip4,LOW);
    digitalWrite(strip5,LOW);
    lightsOn = false; // Update the bool to say lights are off
  }

  else
  {
    mp3.playTrack(1);
    digitalWrite(strip1,HIGH);
    digitalWrite(strip2,HIGH);
    digitalWrite(strip3,HIGH);
    digitalWrite(strip4,HIGH);
    digitalWrite(strip5,HIGH);
    lightsOn = true; // Update the bool to say lights are on
  }

  Serial.println("Setup complete");
}

void loop() 
{
  switchState = digitalRead(scareSwitch);
  
  if (switchState == 0)
  {
    digitalWrite (relay1, LOW);
    Serial.println ("SPOOKY");
  }

  else
  {
    digitalWrite (relay1, HIGH);
    Serial.println ("SAFE");
  }

  reedSwitch.update();
  rfidSwitch.update();
  circsqtriSwitch.update();
  flickerSwitch.update();
  // volDownSwitch.update();
  // volUpSwitch.update();

  if(circsqtriSwitch.fell())
  {
    Serial.println("1612 complete");
    digitalWrite(circsqtriSig, LOW); // Tell the scare uno that 1612 has been input
    firstcams();
  }

  if(rfidSwitch.fell())
  {
    Serial.println("rfid complete");
    digitalWrite (doorSig, LOW); // Tell the scare uno that the door has been opened
    dooropen();
  }

  if(reedSwitch.fell())
  {
    Serial.println("reed complete");
    digitalWrite(reedSig, LOW); // Tell scare uno that the magnet is in the recepticle
    firstobjective();
  }

    if(flickerSwitch.fell())
  {
    Serial.println("flicker complete");
    flicker();
  }
}

void flicker()
{
  Serial.println(lightsOn);
  Serial.println("flickering");
  if (lightsOn == true)
  {
    Serial.println("flickering off");
    digitalWrite(strip1, HIGH);
    digitalWrite(strip2, HIGH);
    digitalWrite(strip3, HIGH);
    digitalWrite(strip4, HIGH);
    digitalWrite(strip5, HIGH);

    delay(random(intMin,intMax)); //1
    digitalWrite(strip2, LOW);

    delay(random(intMin,intMax)); //2
    digitalWrite(strip4, LOW);

    delay(random(intMin,intMax)); //3
    digitalWrite(strip1, LOW);
    digitalWrite(strip2, HIGH);

    delay(random(intMin,intMax)); //4
    digitalWrite(strip1, HIGH);
    digitalWrite(strip3, LOW);
    digitalWrite(strip4, HIGH);

    delay(random(intMin,intMax)); //5
    digitalWrite(strip1, LOW);
    digitalWrite(strip2, LOW);

    delay(random(intMin,intMax)); //6
    digitalWrite(strip2, HIGH);
    digitalWrite(strip4, LOW);

    delay(random(intMin,intMax)); //7
    digitalWrite(strip1, HIGH);
    digitalWrite(strip3, HIGH);
    digitalWrite(strip5, LOW);

    delay(random(intMin,intMax)); //8
    digitalWrite(strip1, LOW);
    digitalWrite(strip2, LOW);
    digitalWrite(strip4, HIGH);

    delay(random(intMin,intMax)); //9
    digitalWrite(strip3, LOW);
    digitalWrite(strip4, LOW);

    delay(random(intMin,intMax)); //10
    digitalWrite(strip1, HIGH);
    digitalWrite(strip4, HIGH);

    delay(random(intMin,intMax)); //11
    digitalWrite(strip1, LOW);

    delay(random(intMin,intMax)); //12
    digitalWrite(strip4, LOW);

    delay(random(intMin,intMax)); //13
    digitalWrite(strip1, LOW);
    digitalWrite(strip2, LOW);
    digitalWrite(strip3, LOW);
    digitalWrite(strip4, LOW);
    digitalWrite(strip5, LOW);
    lightsOn = false; //Lights are off
    Serial.println("lights are off");

  }
  else
  {
    Serial.println("flickering on");
    digitalWrite(strip1, LOW);
    digitalWrite(strip2, LOW);
    digitalWrite(strip3, LOW);
    digitalWrite(strip4, LOW);
    digitalWrite(strip5, LOW);

    delay(random(intMin,intMax)); //1
    digitalWrite(strip2, HIGH);

    delay(random(intMin,intMax)); //2
    digitalWrite(strip4, HIGH);

    delay(random(intMin,intMax)); //3
    digitalWrite(strip1, HIGH);
    digitalWrite(strip2, LOW);

    delay(random(intMin,intMax)); //4
    digitalWrite(strip1, LOW);
    digitalWrite(strip3, HIGH);
    digitalWrite(strip4, LOW);

    delay(random(intMin,intMax)); //5
    digitalWrite(strip1, HIGH);
    digitalWrite(strip2, HIGH);

    delay(random(intMin,intMax)); //6
    digitalWrite(strip2, LOW);
    digitalWrite(strip4, HIGH);

    delay(random(intMin,intMax)); //7
    digitalWrite(strip1, LOW);
    digitalWrite(strip3, LOW);
    digitalWrite(strip5, HIGH);

    delay(random(intMin,intMax)); //8
    digitalWrite(strip1, HIGH);
    digitalWrite(strip2, HIGH);
    digitalWrite(strip4, LOW);

    delay(random(intMin,intMax)); //9
    digitalWrite(strip3, HIGH);
    digitalWrite(strip4, HIGH);

    delay(random(intMin,intMax)); //10
    digitalWrite(strip1, LOW);
    digitalWrite(strip4, LOW);

    delay(random(intMin,intMax)); //11
    digitalWrite(strip1, HIGH);

    delay(random(intMin,intMax)); //12
    digitalWrite(strip4, HIGH);

    delay(random(intMin,intMax)); //13
    digitalWrite(strip1, HIGH);
    digitalWrite(strip2, HIGH);
    digitalWrite(strip3, HIGH);
    digitalWrite(strip4, HIGH);
    digitalWrite(strip5, HIGH);
    Serial.println("lights are on");
    lightsOn = true; // Lights are on
  }
}
void firstcams()
{
  // Turn on cams 1 to 4
  digitalWrite (cam[0], HIGH);
  delay(100);
  digitalWrite (cam[1], HIGH);
  delay(100);
  digitalWrite (cam[2], HIGH);
  delay(100);
  digitalWrite (cam[3], HIGH);
  delay(100); 

  // Attention getting buzzes      
  digitalWrite (buzzPin, HIGH);
  delay(400);
  digitalWrite (buzzPin, LOW);
  delay(400);
  digitalWrite (buzzPin, HIGH);
  delay(400);
  digitalWrite (buzzPin, LOW);
  delay(400);
  digitalWrite (buzzPin, HIGH);
  delay(400);
  digitalWrite (buzzPin, LOW);
  delay(400);

// Cam 1 lights
  digitalWrite (buzzPin, HIGH);
  digitalWrite (r1, LOW);
  delay(100);
  digitalWrite (buzzPin, LOW);
  digitalWrite (r1, HIGH);
  delay(150);
  digitalWrite (buzzPin, HIGH);
  digitalWrite (r1, LOW);
  delay(100);
  digitalWrite (buzzPin, LOW);
  digitalWrite (r1, HIGH);
  delay(150);
  digitalWrite (buzzPin, HIGH);
  digitalWrite (r1, LOW);
  delay(100);
  digitalWrite (buzzPin, LOW);
  digitalWrite (r1, HIGH);
  delay(150);
  digitalWrite (r1, LOW);
  delay(50);
  digitalWrite (buzzPin, HIGH);
  digitalWrite (g1, HIGH);
  delay(500);
  digitalWrite (buzzPin, LOW);
  delay(100);

  // Cam 2 lights
  digitalWrite (buzzPin, HIGH);
  digitalWrite (r2, LOW);
  delay(100);
  digitalWrite (buzzPin, LOW);
  digitalWrite (r2, HIGH);
  delay(150);
  digitalWrite (buzzPin, HIGH);
  digitalWrite (r2, LOW);
  delay(100);
  digitalWrite (buzzPin, LOW);
  digitalWrite (r2, HIGH);
  delay(150);
  digitalWrite (buzzPin, HIGH);
  digitalWrite (r2, LOW);
  delay(100);
  digitalWrite (buzzPin, LOW);
  digitalWrite (r2, HIGH);
  delay(150);
  digitalWrite (r2, LOW);
  delay(50);
  digitalWrite (buzzPin, HIGH);
  digitalWrite (g2, HIGH);
  delay(500);
  digitalWrite (buzzPin, LOW);
  delay(100);

  // Cam 2 lights
  digitalWrite (buzzPin, HIGH);
  digitalWrite (r3, LOW);
  delay(100);
  digitalWrite (buzzPin, LOW);
  digitalWrite (r3, HIGH);
  delay(150);
  digitalWrite (buzzPin, HIGH);
  digitalWrite (r3, LOW);
  delay(100);
  digitalWrite (buzzPin, LOW);
  digitalWrite (r3, HIGH);
  delay(150);
  digitalWrite (buzzPin, HIGH);
  digitalWrite (r3, LOW);
  delay(100);
  digitalWrite (buzzPin, LOW);
  digitalWrite (r3, HIGH);
  delay(150);
  digitalWrite (r3, LOW);
  delay(50);
  digitalWrite (buzzPin, HIGH);
  digitalWrite (g3, HIGH);
  delay(500);
  digitalWrite (buzzPin, LOW);
  delay(100);

  // Cam 4 lights
  digitalWrite (buzzPin, HIGH);
  digitalWrite (r4, LOW);
  delay(100);
  digitalWrite (buzzPin, LOW);
  digitalWrite (r4, HIGH);
  delay(150);
  digitalWrite (buzzPin, HIGH);
  digitalWrite (r4, LOW);
  delay(100);
  digitalWrite (buzzPin, LOW);
  digitalWrite (r4, HIGH);
  delay(150);
  digitalWrite (buzzPin, HIGH);
  digitalWrite (r4, LOW);
  delay(100);
  digitalWrite (buzzPin, LOW);
  digitalWrite (r4, HIGH);
  delay(150);
  digitalWrite (r4, LOW);
  delay(50);
  digitalWrite (buzzPin, HIGH);
  digitalWrite (g4, HIGH);
  delay(500);
  digitalWrite (buzzPin, LOW);
  delay(1000);

  digitalWrite (relay3, HIGH);
  digitalWrite (buzzPin, HIGH);
  delay(600);

  digitalWrite(buzzPin, LOW);

  return;
}

void dooropen()
{
  if (switchState == 0)
  {
    delay(JSmp3); // Provide delay for longer voice over
  }

  else
  {
    delay(NSmp3); // Provide delay for less scary voice over
  }

  // Turn on cams 5, 6 and 7
  digitalWrite (cam[4], HIGH);
  delay(100);
  digitalWrite (cam[5], HIGH);
  delay(100);
  digitalWrite (cam[6], HIGH);
  delay(100);

  // Attention getting buzzes
  for (int i=0;i<3;i++)
  {
    digitalWrite (r5, LOW);
    digitalWrite (r6, LOW);
    digitalWrite (r7, LOW);
    digitalWrite (buzzPin, HIGH);
    delay(400);
    digitalWrite (buzzPin, LOW);
    digitalWrite (r5, HIGH);
    digitalWrite (r6, HIGH);
    digitalWrite (r7, HIGH);
    delay(400);
  }

  // Notify players that the cams have been made available
  digitalWrite (r5, LOW);
  digitalWrite (r6, LOW);
  digitalWrite (r7, LOW);
  delay(250);
  digitalWrite (g5, HIGH);
  digitalWrite (g6, HIGH);
  digitalWrite (g7, HIGH);
  digitalWrite (buzzPin, HIGH);
  delay(1000);
  digitalWrite (buzzPin, LOW);

  // Unlock main door
  digitalWrite (relay2, HIGH);
  digitalWrite (buzzPin, HIGH); 
  delay(600);
  digitalWrite (buzzPin, LOW);

  if (switchState == 0) // If scare mode is on, start the sequence to control the volume up and down sequence
  {
    Serial.println("jump scares are on");
    delay(1000);
    jumpScare = true;
    
    do
    {
      volDownSwitch.update();
      // volUpSwitch.update();
      Serial.println("listening for ultrasound and plug");

      if(volDownSwitch.fell())
      {
        Serial.println("ultrasound triggered");
        for (int i=0;i<30;i++)
        {
          mp3.volumeDec();
          delay(volInterval);
        }
        mp3.volume(0);
      }
      if(volUpSwitch.fell())
      {
        Serial.println("plug connected");
        delay(FHstrike); //Delay for the facehugger to strike
        flicker(); // Flicker the lights on
        mp3.playTrack(3); // Play the spooky alien stompy ambience

        for (int i=0;i<30;i++)
        {
          mp3.volumeInc();
          delay(volInterval);
        }
        mp3.volume(30);
        jumpScare = false; // Now that the volumeUp has been triggered, push us out of the do while loop
      }
    } while (jumpScare == true);
    Serial.println("left do loop");
  }    
  return;
}

void firstobjective()
{
    digitalWrite (wReed, LOW);
    
    for (int i=0;i<8;i++)
    {
      digitalWrite (rReed, HIGH);
      delay(250);
      digitalWrite (rReed, LOW);
      delay(250);
    }
    digitalWrite (gReed, HIGH);
    digitalWrite (cam[7], HIGH); // Turn on camera
    delay(2000);
    
    for (int i=0;i<10;i++)
    {
      digitalWrite (r8, LOW);
      digitalWrite (buzzPin, HIGH);
      delay(250);
      digitalWrite (r8, HIGH);
      digitalWrite (buzzPin, LOW);
      delay(250);
    }

    digitalWrite(r8, LOW);
    delay(100);
    digitalWrite (g8, HIGH);
    digitalWrite (buzzPin, HIGH);
    delay(1000);
    digitalWrite (buzzPin, LOW);
    delay(500);
    return;
}

Mega diagram

Keypad code (This behaves in a way that it should)

// Include libraries
#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <Keypad.h>

// Length of password + 1 for null character
#define Password_Length 5

// Character to hold password input
char Data[Password_Length];

// Password
char pass[Password_Length] = "2193";

// Pin connected to LED control, relay and buzzer
int lockPin = 12;
int buzzPin = 13;
int rPin = 14;
int gPin = 27;
int successPin = 26;

// Counter for character entries
byte data_count = 0;

// Character to hold key input
char customKey;

// Constants for row and column sizes
const byte ROWS = 4;
const byte COLS = 4;

// Array to represent keys on keypad
char hexaKeys[ROWS][COLS] = 
{
  {'1', '2', '3', 'A'},
  {'4', '5', '6', 'B'},
  {'7', '8', '9', 'C'},
  {'*', '0', '#', 'D'}
};

// Connections to Arduino
byte rowPins[ROWS] = {16, 17, 5, 18};
byte colPins[COLS] = {15, 2, 0, 4};

// Create keypad object
Keypad customKeypad = Keypad(makeKeymap(hexaKeys), rowPins, colPins, ROWS, COLS);

// Create LCD object
LiquidCrystal_I2C lcd(0x27, 16, 2); // other address is 3f


void setup() 
{
  // Setup LCD with backlight and initialize
  lcd.backlight();
  lcd.init();
  Serial.begin (9600);
  Serial.println ("Serial has begun");

  // Set pin modes
  pinMode(lockPin, OUTPUT);
  digitalWrite(lockPin, HIGH);
  pinMode(buzzPin, OUTPUT);
  pinMode(rPin, OUTPUT);
  pinMode(gPin, OUTPUT);
  pinMode(successPin, OUTPUT);

  // Initiate test

  delay (2000);

  for (int i = 0; i < 2; i++)
  {
    Serial.println ("test");
    digitalWrite (rPin, LOW);
    digitalWrite (gPin, LOW);
    digitalWrite (buzzPin, LOW);
    delay (200);

    // lcd.print ("test");
    digitalWrite (rPin, HIGH);
    delay (200);
    digitalWrite (gPin, HIGH);
    delay (200);
    digitalWrite (buzzPin, HIGH);
    delay (200);
    digitalWrite (buzzPin, LOW);
    digitalWrite (rPin, LOW);
    digitalWrite (gPin, LOW);
    delay (200);
    digitalWrite (rPin, HIGH);
    delay (200);
    digitalWrite (rPin, LOW);
    delay (200);
    digitalWrite (gPin, HIGH);
    delay (200);
    digitalWrite (gPin, LOW);
    delay (200);
    digitalWrite (buzzPin, HIGH);
    delay (200);
    digitalWrite (buzzPin, LOW);
    delay (200);
  }
  
}

void loop() 
{
  digitalWrite (rPin, HIGH);
  
  // Initialize LCD and print
  lcd.setCursor(0, 0);
  lcd.print("JUMP 7 CODE:");

  // Look for keypress
  customKey = customKeypad.getKey();
  
  if (customKey) 
  {
    // Enter keypress into array and increment counter
    Data[data_count] = customKey;
    lcd.setCursor(data_count, 1);
    lcd.print(Data[data_count]);
    data_count++;

    // Play a buzz when a key is pressed
    digitalWrite (buzzPin, HIGH);
    digitalWrite (gPin, HIGH);
    digitalWrite (rPin, LOW);
    delay (100);
    digitalWrite (buzzPin, LOW);
    digitalWrite (gPin, LOW);
    digitalWrite (rPin, HIGH);
  }

  // See if we have reached the password length
  if (data_count == Password_Length - 1) 
  {
    lcd.clear();
     
    if (!strcmp(Data, pass)) 
    {
      // Password is correct
      lcd.print("VIEWPORT OPEN");
      delay(500);
      digitalWrite (gPin, HIGH);
      digitalWrite (rPin, LOW);
      delay (1000);
      digitalWrite (successPin, LOW); // Tell mega to initiate firstCams
      digitalWrite (buzzPin, HIGH);
      digitalWrite (lockPin, LOW);
      delay (600);
      digitalWrite (successPin, HIGH);
      digitalWrite (buzzPin, LOW);
      digitalWrite (lockPin, HIGH);
      delay(1800000);

      lcd.clear();
      clearData();
      delay (100);
      digitalWrite (buzzPin, LOW);
      digitalWrite (rPin, HIGH);
      digitalWrite (gPin, LOW);
      
      return;
    }
      
    else 
    {
      // Password is incorrect, play a quick double tone and display error message
      lcd.print("INCORRECT CODE");
      delay(500);   
      digitalWrite(buzzPin, HIGH);
      digitalWrite(rPin, HIGH);
      delay(50);
      digitalWrite(buzzPin, LOW);
      digitalWrite(rPin, LOW);
      delay(75);
      digitalWrite(buzzPin, HIGH);
      digitalWrite(rPin, HIGH);
      delay(50);
      digitalWrite(buzzPin, LOW);
      digitalWrite(rPin, LOW);
      delay(75);
      digitalWrite(buzzPin, HIGH);
      digitalWrite(rPin, HIGH);
      delay(50);
      digitalWrite(buzzPin, LOW);
      digitalWrite(rPin, LOW);    
      delay (1000);
    }

    // Clear data and LCD display
    lcd.clear();
    lcd.print("Data reset");
    digitalWrite (buzzPin, HIGH);
    delay (500);  
    digitalWrite (buzzPin, LOW);
      
    lcd.clear();
    clearData();
  }
}

void clearData() {
  // Go through array and clear data
  while (data_count != 0) 
  {
    Data[data_count--] = 0;
  }
  return;
}

[StefanL38]

very detailed description but confusing.
my personal experience is:

In 90% of all cases presenting parts of code does not help.

Your not presented code can have zillion ways to make it not work.
And this is the reason why the complete sketch must be analysed.

A lot of problems can be narrowed down by serial printing of

• names and values of variables
• code printing I am about to execute line ....
  or
  code printing I have right before executed line ....

where each and every of these printings has some kind of a unique identifier to make very clear it is this single particular line of code

The best thing These fritzy pictures can do is look fancy.
Fritzy pictures are bad about being focused on the real important information.

You shold hand-draw schematics that show that IO-pins that are relevant.

As you are using so looong wires there might be a problem with ground-loops

How to provide an easy to read schematic and how not

This tutorial shall show how to provide an easy to read schematic of your wiring and how you should not post fritzing pictures don't post frizzy-pictures like that! if you look at this pictures please tell me the IO-pin-numbers! What ?? You can't read the IO-pin-numbers? You have to download the picture and than zoom in. Don't you have time? You have to download the datasheet of the chip and then look up which pin is connected to what. take additional time to count through the chip-pins …

best regards Stefan

[milklizard88]

Thanks for the help, I'll look into what you've said, but, the first line of my post said "I've posted unabriged code and schematics at bottom of the post" OWTTE.

The full code was provided in the post (unless I'm misunderstanding your response)

[david_2018]

@milklizard88

I initially solved it by writing the 3 mega pins high in setup, then they worked. The problem is it caused some funny business with the UNO, in particular when I disconnected Vin and gnd from the UNO, it was still powered through these pins that were getting this high signal.

Put a diode in-line between the Mega and UNO, so that the Mega output can only pull the UNO pin LOW. The HIGH level is then provided by the internal pullup on the UNO, and you will not get phantom powering from the Mega. Of course, if you never have the Mega output set to HIGH, there cannot be a transition from HIGH to LOW.

Why are you running software serial on a Mega, when you have three unused hardware serial ports?

[milklizard88]

@david_2018

Put a diode in-line between the Mega and UNO, so that the Mega output can only pull the UNO pin LOW. The HIGH level is then provided by the internal pullup on the UNO, and you will not get phantom powering from the Mega.

Good idea thank you, I'll do that and report back, it has worked for me at other times in the past not having the pin go "high to low" but go "inactive to low" and still work, but I'll try the diodes.

@david_2018

Why are you running software serial on a Mega, when you have three unused hardware serial ports?

I've reused and adapted the code from an uno running an mp3 player and an I2C LCD screen simultaneously, I just haven't bothered removing it

[StefanL38]

Here is a code-version of your Unoc-code with additional serial debug macros

It does compile

// MACRO-START * MACRO-START * MACRO-START * MACRO-START * MACRO-START * MACRO-START *
// a detailed explanation how these macros work is given in this tutorial
// https://forum.arduino.cc/t/comfortable-serial-debug-output-short-to-write-fixed-text-name-and-content-of-any-variable-code-example/888298

#define dbg(myFixedText, variableName) \
  Serial.print( F(#myFixedText " "  #variableName"=") ); \
  Serial.println(variableName);

#define dbgi(myFixedText, variableName,timeInterval) \
  { \
    static unsigned long intervalStartTime; \
    if ( millis() - intervalStartTime >= timeInterval ){ \
      intervalStartTime = millis(); \
      Serial.print( F(#myFixedText " "  #variableName"=") ); \
      Serial.println(variableName); \
    } \
  }

#define dbgc(myFixedText, variableName) \
  { \
    static long lastState; \
    if ( lastState != variableName ){ \
      Serial.print( F(#myFixedText " "  #variableName" changed from ") ); \
      Serial.print(lastState); \
      Serial.print( F(" to ") ); \
      Serial.println(variableName); \
      lastState = variableName; \
    } \
  }

#define dbgcf(myFixedText, variableName) \
  { \
    static float lastState; \
    if ( lastState != variableName ){ \
      Serial.print( F(#myFixedText " "  #variableName" changed from ") ); \
      Serial.print(lastState); \
      Serial.print( F(" to ") ); \
      Serial.println(variableName); \
      lastState = variableName; \
    } \
  }
// MACRO-END * MACRO-END * MACRO-END * MACRO-END * MACRO-END * MACRO-END * MACRO-END *

unsigned long MyTestTimer = 0;                   // Timer-variables MUST be of type unsigned long
const byte    OnBoard_LED = 2;     // onboard-LEDESP32 / ESP8266
//const byte    OnBoard_LED = 25;  // onboard-LED Raspberry Pi pico
//const byte    OnBoard_LED = 13;   // onboard-LED uno, mega

/*
  Serial.begin(115200);
  Serial.println("Setup-Start");
  PrintFileNameDateTime();

  BlinkHeartBeatLED(OnBoard_LED,250);

  if ( TimePeriodIsOver(MyTestTimer,1000) ) {

  }

*/

// Scare control UNO

#include <AltSoftSerial.h> // Alt serial library, see library folder in dropbox
#include <Wire.h>
#include <MD_YX5300.h> // See library folder in dropbox
#include <Bounce2.h> // For debouncing button input. See https://github.com/thomasfredericks/Bounce2

// Tunable variables - These are so you can sync up sounds and scares easily

int FHdim = 1500; // Time for the spotlight to dim after the MP3 has been triggered
int FHrelay = 1500; // Time for relay to hit
int BYdelay1 = 5000; // Time for first behind you after reed trigger
int BYdelay2 = 5000; // Time for second behind you after first behind you
int BYflicker1 = 5000; // Time for first flicker pulse
int BYflicker2 = 5000; // Time for second flicker pulse
int fadeAmount = 5;  // how many points to fade the spotlight by
int fadeinTime = 50; // how quickly to fade the spotlight up (this is slower)
int fadeoutTime = 20; // how quickly to fade the spotlight up (this is quick)

// Input pins

int hiss = 12;
int hissSelect; // Random number to select which hiss mp3 to select
int flicker = 6;
int exhale = 10;
int baby = 11;


// Output pins

int megaFlicker = A5;
int megavolumeDown = 2;

// Input triggers

int circsqtriPin = A0; // Trigger for 1612 and starts violet attack countdown
int rfidPin = A1; // Trigger the facehugger sequence
int jump7Pin = A2; // Trigger the window opening sounds
int reedPin = A3; // Trigger any behind you sequence
int plugPin = A4; // Trigger the scare
int ultrasoundPin = 7;

// Pins for scare switch
int scareSwitch = 13; // This is pulled low when scares are being turned on.
int switchState; //

// Utility

int spotlight = 5; // PWM pin to control the brightness of the light (via MOSFET)
int brightness = 0;  // how bright the spotlight is
int lightRelay = 3; // Relay attached to light NO is floor NC is hand
int facehuggerRelay = 4; // Relay to release the facehugger scare

bool plugState = false; // Keeps the "waiting for plug" loop going

// GLOBALS

// Create an array of Bounce objects for each input button

Bounce circsqtriSwitch = Bounce();
Bounce reedSwitch = Bounce();
Bounce rfidSwitch = Bounce();
Bounce jump7Switch = Bounce();
Bounce plugSwitch = Bounce();
Bounce ultrasoundSwitch = Bounce();

Bounce hissSwitch = Bounce();
Bounce exhaleSwitch = Bounce();
Bounce babySwitch = Bounce();
Bounce flickerSwitch = Bounce();

// Initialise a software serial interface on the approriate Rx/Tx pins (8/9)
AltSoftSerial altSerial;
// And create an MP3 object based on the serial connection
MD_YX5300 mp3(altSerial);

void setup()
{
  delay (10000);

  // Initialise a serial connection (used for debugging only)
  Serial.begin(115200);
  Serial.println(__FILE__ __DATE__);
  Serial.println("Serial connection initialised");

  Serial.println ("Setup 2 begun, buffer initiated");
  delay (10000);
  Serial.println ("Buffer 2 complete");

  reedSwitch.attach(reedPin, INPUT_PULLUP);
  rfidSwitch.attach(rfidPin, INPUT_PULLUP);
  circsqtriSwitch.attach(circsqtriPin, INPUT_PULLUP);
  jump7Switch.attach(jump7Pin, INPUT_PULLUP);
  plugSwitch.attach(plugPin, INPUT_PULLUP);
  ultrasoundSwitch.attach(ultrasoundPin, INPUT_PULLUP);

  hissSwitch.attach(hiss, INPUT_PULLUP);
  flickerSwitch.attach(flicker, INPUT_PULLUP);
  exhaleSwitch.attach(exhale, INPUT_PULLUP);
  babySwitch.attach(baby, INPUT_PULLUP);

  Serial.println("Utility buttons initialised");

  // Scare mode?
  pinMode (scareSwitch, INPUT_PULLUP);
  switchState = digitalRead(scareSwitch);
  Serial.println(switchState);

  // Initialise pins and test

  pinMode(megaFlicker, OUTPUT);
  pinMode(megavolumeDown, OUTPUT);

  pinMode(spotlight, OUTPUT);
  pinMode(facehuggerRelay, OUTPUT);
  digitalWrite(facehuggerRelay, LOW);
  pinMode(lightRelay, OUTPUT);
  digitalWrite (lightRelay, LOW);

  // Test

  // Initialise the serial interface to the MP3 player
  altSerial.begin(9600);
  mp3.begin();
  mp3.volume(30);
  delay(1000);

  if (switchState == 0) {
    Serial.print(switchState);
    mp3.playTrack(1); // "Horror mode is turned on"
    Serial.println ("Horror mode is turned ON");

  }
  else {
    Serial.print(switchState);
    mp3.playTrack(2); // "Horror mode is turned off"
    Serial.println ("Horror mode is turned OFF");
  }

  delay(1000);
  Serial.println("Setup complete");
}

void loop()
{
  switchState = digitalRead(scareSwitch);
  // Serial.print(switchState);

  dbgc("01",digitalRead(scareSwitch));
/*
  if (switchState == 0) {
    // Serial.println("SPOOKY");
  }
  else {
    Serial.println("Safe");
  }
*/
  reedSwitch.update();
  rfidSwitch.update();
  circsqtriSwitch.update();
  jump7Switch.update();

  hissSwitch.update();
  flickerSwitch.update();
  exhaleSwitch.update();
  babySwitch.update();

  dbgc("02",circsqtriSwitch.fell() );
  if (circsqtriSwitch.fell())
  {
    Serial.println("1612 complete");
    violentAttack();
  }

  dbgc("03",rfidSwitch.fell() );
  if (rfidSwitch.fell())
  {
    Serial.println("rfid complete");

    //Todo light relay change

    if (switchState == 0)
    {
      Serial.println("SCARES ARE ON");
      jumpScare();
    }
    else
    {
      Serial.println("SCARES ARE OFF");
      noScare();
    }
  }

  dbgc("03",jump7Switch.fell() );
  if (jump7Switch.fell())
  {
    Serial.println("jump7 complete");
    cryBabies();
  }

  dbgc("04",reedSwitch.fell() );
  if (reedSwitch.fell())
  {
    Serial.println("reed complete");

    behindYou();

  }

  dbgc("05",flickerSwitch.fell() );
  if (flickerSwitch.fell())
  {
    Serial.println("flicker");
    {
      sendFlicker();
    }
  }

  dbgc("06",babySwitch.fell() );
  if (babySwitch.fell())
  {
    Serial.println("baby");

    if (switchState == 0)

    {
      mp3.playTrack(10);
    }
  }

  dbgc("07",hissSwitch.fell() );
  if (hissSwitch.fell())
  {
    Serial.println("hiss");
    if (switchState == 1)
    {
      whataHisser();
    }
  }

  dbgc("08",exhaleSwitch.fell() );
  if (exhaleSwitch.fell())
  {
    Serial.println("exhale");

    if (switchState == 1)
    {
      mp3.playTrack(11);
    }
  }
}

void violentAttack()
{
  Serial.println("in function violentAttack");

  if (switchState == 0)
  {
    Serial.println("playing violent attack");
    delay(45000);
    mp3.playTrack(3);
  }
  return;
}

void jumpScare() // TO DO
{
  Serial.println("in jumpScare");
  digitalWrite(lightRelay, HIGH);
  mp3.playTrack(7);
  int ultrasoundPinging = true;

  do
  {
    plugSwitch.update();
    ultrasoundSwitch.update();

    if (ultrasoundSwitch.fell())
    {
      mp3.playTrack(5); // Facehugger cry
      ultrasoundPinging = false; // Cease this IF statement in future
      spotlightOn(); // Turn on spotlight

      digitalWrite(megavolumeDown, LOW); // Send volume down signal
      delay(200);
      digitalWrite(megavolumeDown, HIGH);
    }

    if (plugSwitch.fell())
    {
      Serial.println("plug connected");
      mp3.playTrack(9);
      delay(FHdim);
      spotlightOff();
      delay(FHrelay);
      digitalWrite (facehuggerRelay, HIGH);
      delay(200);
      digitalWrite(facehuggerRelay, LOW);
      plugState = true;
      delay(2000);
      digitalWrite(lightRelay, LOW);


      digitalWrite(megavolumeDown, LOW); // Send volume up signal
      delay(200);
      digitalWrite(megavolumeDown, HIGH);
    }
  }
  while (plugState == false);
}

void noScare()
{
  Serial.println ("in noScare");
  mp3.playTrack(8);
  return;
}

void cryBabies ()
{
  if (switchState == 0)
  {
    delay(10000);
    mp3.playTrack(5);
    delay(60000);
    mp3.playTrack(4);
  }

  else
  {
    return;
  }
}

void behindYou()
{
  switchState = digitalRead(scareSwitch);
  Serial.println(switchState);

  if (switchState == 0)
  {
    delay (BYdelay1);
    mp3.playTrack(12);
    delay (BYdelay2);
    sendFlicker();
    delay (BYflicker1);
    mp3.playTrack(13);
    delay (BYflicker2);
    sendFlicker();
  }
  else
  {
    return;
  }
}

void spotlightOn()
{
  brightness = 0;
  do
  {
    analogWrite(spotlight, brightness); // Set current brightness
    // Serial.println (brightness);
    brightness = brightness + fadeAmount; // Increase brightness
    delay(fadeinTime);
  }
  while (brightness <= 225); // Till brightness maxed

  analogWrite(spotlight, 225);

  return;
}

void spotlightOff()
{
  do
  {
    analogWrite(spotlight, brightness); // Set current brightness
    // Serial.println (brightness);
    brightness = brightness - fadeAmount; // Decrease brightness
    delay(fadeoutTime);

  }
  while (brightness >= 0); // Till brightness at minimum

  analogWrite(spotlight, 0);
  return;
}

void whataHisser()
{
  hissSelect = random(3);
  Serial.println (hissSelect);

  if (hissSelect == 0)
  {
    mp3.playTrack(14);
  }
  else if (hissSelect == 1)
  {
    mp3.playTrack(15);
  }
  else if (hissSelect == 2)
  {
    mp3.playTrack(16);
  }
}

void sendFlicker()
{
  if (switchState == 0)
  {
    digitalWrite(megaFlicker, LOW);
    delay(200);
    digitalWrite(megaFlicker, HIGH);
    mp3.playTrack(18);
  }
}

// helper-functions
void PrintFileNameDateTime() {
  Serial.println( F("Code running comes from file ") );
  Serial.println( F(__FILE__) );
  Serial.print( F("  compiled ") );
  Serial.print( F(__DATE__) );
  Serial.print( F(" ") );
  Serial.println( F(__TIME__) );
}


// easy to use helper-function for non-blocking timing
boolean TimePeriodIsOver (unsigned long &startOfPeriod, unsigned long TimePeriod) {
  unsigned long currentMillis  = millis();
  if ( currentMillis - startOfPeriod >= TimePeriod ) {
    // more time than TimePeriod has elapsed since last time if-condition was true
    startOfPeriod = currentMillis; // a new period starts right here so set new starttime
    return true;
  }
  else return false;            // actual TimePeriod is NOT yet over
}



void BlinkHeartBeatLED(int IO_Pin, int BlinkPeriod) {
  static unsigned long MyBlinkTimer;
  pinMode(IO_Pin, OUTPUT);

  if ( TimePeriodIsOver(MyBlinkTimer, BlinkPeriod) ) {
    digitalWrite(IO_Pin, !digitalRead(IO_Pin) );
  }
}

[david_2018]

@milklizard88

it has worked for me at other times in the past not having the pin go "high to low" but go "inactive to low" and still work, but I'll try the diodes.

Since you are using INPUT_PULLUP on the UNO, you should be able to set the Mega pin to INPUT mode for a HIGH signal, then OUTPUT mode and LOW for a LOW signal.

[milklizard88]

Sorry I'm not quite sure what you did to my code there, I'm sure it makes sense to you but I'm an amateur.

You'll have to forgive me for having difficult to read code, trying my best over here. Spent a decent chunk of time on my post trying to make it easy to follow but it seems to have had the opposite effect.

Thanks for your help though Stefan

[milklizard88]

@david_2018

@milklizard88

it has worked for me at other times in the past not having the pin go "high to low" but go "inactive to low" and still work, but I'll try the diodes.

Since you are using INPUT_PULLUP on the UNO, you should be able to set the Mega pin to INPUT mode for a HIGH signal, then OUTPUT mode and LOW for a LOW signal.

Intersting, I'll give that a try

[gcjr]

there should be no problem with one 5V digital output driving a 5V digital input with a common ground

have you tried using very simple programs:
one that simply drives sets an LED to the same state as an input pin, as well as an output pin connected to the other board, and

on the other board a program that toggles every sec a pin connected the input pin on the other processor as well as setting an LED pin to the input pin connected to the other board

// echo input pin to LED and output pin

const byte PinInp  = A2;
const byte PinOut  = A3;

const byte PinLed  = 13;

void
loop (void)
{
    digitalWrite (PinLed, digitalRead (PinInp));
    digitalWrite (PinOut, digitalRead (PinInp));
}

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

    pinMode (PinInp,  INPUT_PULLUP);

    pinMode (PinOut,  OUTPUT);
    pinMode (PinLed,  OUTPUT);
}

// toggle output pin every sec, echo input pin on LED

const byte PinInp  = A2;
const byte PinOut  = A3;

const byte PinLed  = 13;

unsigned long msec0;

void
loop (void)
{
    unsigned long msec = millis ();
    if (msec - msec0 >= 1000)  {
        msec0 = msec;
        digitalWrite (PinOut, ! digitalRead (PinOut));
    }
    digitalWrite (PinLed, digitalRead (PinInp));
}

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

    pinMode (PinInp,  INPUT_PULLUP);

    pinMode (PinOut,  OUTPUT);
    pinMode (PinLed,  OUTPUT);
}

[david_2018]

@gcjr

there should be no problem with one 5V digital output driving a 5V digital input with a common ground

Other than the issue of parasitic powering the UNO from the Mega.

@milklizard88

The problem is it caused some funny business with the UNO, in particular when I disconnected Vin and gnd from the UNO, it was still powered through these pins that were getting this high signal.

[gcjr]

@david_2018

Other than the issue of phantom powering the UNO from the Mega.

are programs running independently on both board with both boards presumably properly powered and with not connections between the boards aside from possibly a common power source >= 8V at Vin?

[milklizard88]

I think this picture answers your question but I'm not sure I might be misunderstanding

[gcjr]

where is the power connections to the Mega?

i see connections to Gnd, A9, A13, A14 and A15

also, Vin to an Arduino needs to be >= 8V
5V can be supplied directly to the 5V connection

[milklizard88]

The jack at the top of the mega is connected to the 9v

I had no idea the Vin needed > 8v, I thought it was 5v! I think I confused my ESP Vin voltage which is 5v, thank you for pointing this out, I shall make the change.

[gcjr]

see Feeding power to Arduino: