#include <SoftwareSerial.h>

// Pins for RS232 communication
const int rs232TxPin = 10; // TX pin for RS232 communication
const int rs232RxPin = 11; // RX pin for RS232 communication

// Pins for toggle button and LED indicators
const int startButtonPin = 2; // Pin for toggle button
const int numIndicatorLEDs = 13; // Number of indicator LEDs
const int indicatorLEDs[] = {3, 4, 5, 6, 7, 8, 9, 12, 13, 14, 15, 16, 17}; // Pins for indicator LEDs

// Pins for relay control
const int relayPin = 18; // Pin for controlling the relay

// Threshold for short circuit detection
const int threshold = 100; // Adjust as needed

bool scanningStarted = false; // Flag to indicate if scanning has started
int currentPin = 0; // Current pin being checked

SoftwareSerial rs232(rs232RxPin, rs232TxPin); // Create a SoftwareSerial object

void setup() {
  Serial.begin(9600); // Initialize serial communication for debugging
  rs232.begin(9600); // Initialize RS232 communication with multimeter
  
  pinMode(startButtonPin, INPUT_PULLUP); // Set start button as input with internal pull-up resistor
  
  // Set indicator LED pins as outputs
  for (int i = 0; i < numIndicatorLEDs; i++) {
    pinMode(indicatorLEDs[i], OUTPUT);
    digitalWrite(indicatorLEDs[i], LOW); // Turn off all LEDs initially
  }
  
  // Set relay pin as output
  pinMode(relayPin, OUTPUT);
  digitalWrite(relayPin, LOW); // Initially turn off relay
}

void loop() {
  // Check if the start button is pressed to toggle scanning
  if (digitalRead(startButtonPin) == LOW) {
    scanningStarted = !scanningStarted; // Toggle scanning status
    
    // Reset current pin index when scanning is started
    if (scanningStarted) {
      currentPin = 0;
    }
    
    delay(500); // Debouncing delay
  }
  
  // If scanning is started, proceed with short circuit check
  if (scanningStarted) {
    // Activate relay to measure resistance on current pin
    digitalWrite(relayPin, HIGH);
    
    // Wait for relay to settle
    delay(100);
    
    // Check if data is available from multimeter
    if (rs232.available() > 0) {
      // Read the value from multimeter
      int value = rs232.parseInt();
      
      // Check for short circuit
      bool isShort = value < threshold;
      
      // Update LED indicator based on short circuit status
      digitalWrite(indicatorLEDs[currentPin], isShort ? HIGH : LOW);
      
      // Move to the next pin for the next iteration
      currentPin = (currentPin + 1) % numIndicatorLEDs;
      
      // Print debug information
      Serial.print("Reading from multimeter: ");
      Serial.print(value);
      Serial.print(" - Pin ");
      Serial.print(currentPin);
      Serial.println(isShort ? " - Short circuit detected!" : " - No short circuit detected.");
      
      delay(1000); // Delay between readings
    }
    
    // Deactivate relay after measurement
    digitalWrite(relayPin, LOW);
  } else {
    // Turn off all indicator LEDs if scanning is not started
    for (int i = 0; i < numIndicatorLEDs; i++) {
      digitalWrite(indicatorLEDs[i], LOW);
    }
  }
}