Interfacing Arduino Nano and Arduino FX Soundboard Standard 16mb

Hello! I'm seeking feasibility advice on how to work through my project. Any help is greatly appreciated!

Overview: I have two separate circuits working independently of one another, each on its own breadboard. One uses an Arduino FX standard soundboard and the other uses an Arduino Nano. Attached are pictures of each circuit.

What I'm trying to do: I'd like to make the soundboard circuit dependent on the input of the nano circuit. For example, when the input (photoresistor) is triggered on the nano circuit, the soundboard circuit becomes the output and begins to play a song.

Again, any help is appreciated!

-Ben

This is my code for the Nano.

//Constants
const int pResistor = A0; // Photoresistor at Arduino analog pin A0
const int soundEffect=9;       // Led pin at Arduino pin 9

//Variables
int value;          // Store value from photoresistor (0-1023)

void setup(){
 pinMode(soundEffect, OUTPUT); // Set lepPin - 9 pin as an output
 pinMode(pResistor, INPUT);// Set pResistor - A0 pin as an input (optional)
  
}

void loop(){
  value = analogRead(pResistor);
  
  //You can change value "25"
  if (value > 750){
    digitalWrite(soundEffect, HIGH);  //Turn led off
  }
  else{
    digitalWrite(soundEffect, LOW); //Turn led on
  }
}

It looks like the FX board can be controlled in either trigger mode or serial mode. If you use trigger mode it looks like all you have to do is hook up the trigger pin to the nano on pin "soundEffect" along with GND and your code should work.