/*
  This sketch uses:
    - A 74HC595 (sr1) connected to digital pins 8 (DS), 9 (SHCP), and 10 (STCP) to drive a
      7-segment display (sevseg1). The segments are mapped as:
         Q0 -> A, Q1 -> B, Q2 -> C, Q3 -> D, Q4 -> E, Q5 -> F, Q6 -> G, Q7 -> DP.
    - A 10-segment LED bar graph (bargraph1) connected to digital pins 22-31.
    - Two LEDs (led1, led2) connected on pins 32 and 33 to indicate even/odd numbers.
  
  Every 2 seconds the counter increments from 0 to 9 and updates all outputs simultaneously.
  
  Note:
    The seven-segment display is assumed to be common anode. Therefore, a segment is lit when
    its corresponding output from the 74HC595 is LOW. The digit patterns are defined accordingly.
*/

#include <Servo.h>  // Included as per allowed packages (though not used in this sketch)

// Pin assignments for the shift register (74HC595)
const int dataPin   = 8;   // DS
const int clockPin  = 9;   // SHCP
const int latchPin  = 10;  // STCP

// LED pins for parity indication
const int ledEvenPin = 32; // led1 will indicate even numbers
const int ledOddPin  = 33; // led2 will indicate odd numbers

// Bar graph LED anode pins (corresponding to bargraph1:A1 ... A10)
const int barGraphPins[10] = {22, 23, 24, 25, 26, 27, 28, 29, 30, 31};

// Seven-segment display lookup table for common-anode configuration.
// For common anode, a segment is lit by driving it LOW. Bit order: bit0=A, bit1=B,..., bit6=G, bit7=DP.
// The digits below come from inverting common-cathode codes {0x3F,0x06,0x5B,0x4F,0x66,0x6D,0x7D,0x07,0x7F,0x6F}
byte digitPatterns[10] = {
  0xC0, // 0 : 0xC0 = ~0x3F
  0xF9, // 1 : ~0x06
  0xA4, // 2 : ~0x5B
  0xB0, // 3 : ~0x4F
  0x99, // 4 : ~0x66
  0x92, // 5 : ~0x6D
  0x82, // 6 : ~0x7D
  0xF8, // 7 : ~0x07
  0x80, // 8 : ~0x7F
  0x90  // 9 : ~0x6F
};

void setup() {
  // Initialize shift register pins
  pinMode(dataPin, OUTPUT);
  pinMode(clockPin, OUTPUT);
  pinMode(latchPin, OUTPUT);
  
  // Initialize LED parity pins
  pinMode(ledEvenPin, OUTPUT);
  pinMode(ledOddPin, OUTPUT);
  
  // Initialize bar graph LED pins
  for (int i = 0; i < 10; i++) {
    pinMode(barGraphPins[i], OUTPUT);
    digitalWrite(barGraphPins[i], LOW); // Turn off initially
  }
  
  // Initially turn off the parity indicator LEDs
  digitalWrite(ledEvenPin, LOW);
  digitalWrite(ledOddPin, LOW);

  // Initialize the seven-segment display to 0 by shifting out the proper pattern.
  updateShiftRegister(digitPatterns[0]);
}

void loop() {
  for (int number = 0; number < 10; number++) {
    // Update the 7-segment display by shifting out digit pattern.
    updateShiftRegister(digitPatterns[number]);
    
    // Update the bar graph: light up first "number" segments.
    for (int i = 0; i < 10; i++) {
      if (i < number) {
        digitalWrite(barGraphPins[i], HIGH);
      }
      else {
        digitalWrite(barGraphPins[i], LOW);
      }
    }
    
    // Update parity LEDs: even --> ledEven on, odd  --> ledOdd on.
    if (number % 2 == 0) {
      digitalWrite(ledEvenPin, HIGH);
      digitalWrite(ledOddPin, LOW);
    }
    else {
      digitalWrite(ledEvenPin, LOW);
      digitalWrite(ledOddPin, HIGH);
    }
    
    // Wait exactly 2 seconds before the next update.
    delay(2000);
  }
}

// Function to update shift register with a byte of data
// Uses shiftOut() with LSBFIRST so that bit0 is shifted first and lands at Q0.
void updateShiftRegister(byte data) {
  digitalWrite(latchPin, LOW);        // Begin output transaction by setting latch low
  shiftOut(dataPin, clockPin, LSBFIRST, data);
  digitalWrite(latchPin, HIGH);       // Latch the output; all connected segments update simultaneously
}