// Заміри напруги на ADC ESP32.

#include <Arduino.h>

// ========= SETTING ===================

#define OLED_SSD1306

// =========/ SETTING ===================


#ifdef OLED_SSD1306
  #include <Wire.h>
  #include <Adafruit_GFX.h>
  #include <Adafruit_SSD1306.h>
  #define SCREEN_WIDTH 128 // OLED display width, in pixels
  #define SCREEN_HEIGHT 64 // OLED display height, in pixels
  // Declaration for an SSD1306 display connected to I2C (SDA, SCL pins)
  // The pins for I2C are defined by the Wire-library. 
  // On an arduino UNO:       A4(SDA), A5(SCL)
  // On an arduino MEGA 2560: 20(SDA), 21(SCL)
  // On an arduino LEONARDO:   2(SDA),  3(SCL), ...
  #define OLED_RESET     -1 // Reset pin # (or -1 if sharing Arduino reset pin)
  #define SCREEN_ADDRESS 0x3C ///< See datasheet for Address; 0x3D for 128x64, 0x3C for 128x32
  Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);
#endif

const int LED_PIN = 2; // 34
const int ADC_PIN = 26; // 34
uint16_t ADC_val = 0;

uint16_t R1 = 1000; //kOm
uint16_t R2 = 2215; //kOm
uint16_t AREF = 3285; //mv

uint16_t ADC_arr[10];
// uint16_t ADC_arr[10] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
// uint16_t ADC_arr[10] = {1, 2, 9, 4, 5, 6, 2, 1, 6, 6};

uint16_t findAverage (void);

void setup()
{
  // Wire.begin();
  Serial.begin(115200);
  
  pinMode(LED_PIN, OUTPUT);
  pinMode(ADC_PIN, INPUT);

  #ifdef OLED_SSD1306
    // Wire.begin(33, 32);
    Wire.begin();
    if(!display.begin(SSD1306_SWITCHCAPVCC, SCREEN_ADDRESS)) {
      Serial.println(F("SSD1306 allocation failed"));
      for(;;); // Don't proceed, loop forever
    }

    display.display();
    delay(2000); // Pause for 2 seconds

    // Clear the buffer
    display.clearDisplay();
    display.setTextSize(2);      // Normal 1:1 pixel scale
    display.setTextColor(SSD1306_WHITE); // Draw white text
    display.setCursor(0, 0);     // Start at top-left corner
  #endif
}



void loop()
{
  float voltage = 0.00;
  uint32_t voltageLong = 0;
  uint16_t averageVal = 0;
  // uint16_t voltage = 0;
  digitalWrite(LED_PIN, HIGH);
  delay(20);
  digitalWrite(LED_PIN, LOW);
  delay(980);


  for(uint8_t i=0; i<10; i++) {
    ADC_arr[i] = analogRead(ADC_PIN);
    delay(5);
  }

  averageVal = findAverage();

  voltageLong = (long)averageVal * (R1+R2) / 1000 * AREF  / 4096;

  int koef = 0;
  if(voltageLong / 1000 > 9) koef = -800;
  else if(voltageLong / 1000 > 8) koef = -270;
  else if(voltageLong / 1000 > 7) koef = 60;
  else if(voltageLong / 1000 > 6) koef = 60;
  else if(voltageLong / 1000 > 5) koef = 70;
  else if(voltageLong / 1000 > 4) koef = 30;
  else if(voltageLong / 1000 > 3) koef = 10;


  voltage = (float)(voltageLong + 422 + koef) / 1000;
  
  

  #ifdef OLED_SSD1306
    display.clearDisplay();
    display.setCursor(0, 18);     // Start at top-left corner
    display.print(F("ADC: "));
    display.print(averageVal);
    display.setCursor(0, 38);
    display.print(F("Vlt: "));
    display.print(voltage);
    display.display(); 
  #endif

  Serial.print("ADC: ");
  Serial.print(averageVal);
  Serial.print(" U: ");
  Serial.println(voltage);
}

/*
Real  ADC
2    624 
3   1003
4   1392
5   1771
6   2150
7   2523
8   2915
9   3376
10  4080
*/


// =================== FUNCTIONS ========================

 // // ======================== SORT ADC +============================
uint16_t findAverage (void){
  int minVal = ADC_arr[0];
  int arrLength = sizeof(ADC_arr) / sizeof(ADC_arr[0]);

  for(int j=1; j<arrLength; j++) {
    for(int i=j; i<arrLength; i++) {
      if(ADC_arr[i] < ADC_arr[j-1]) {
        minVal = ADC_arr[j-1];
        ADC_arr[j-1] = ADC_arr[i];
        ADC_arr[i] = minVal;
      }
    }
    // Serial.print("ADC_arr[] = ");
    // Serial.println(ADC_arr[j-1]);
  }
  // Serial.print("sortArr[] = ");
  // Serial.println(ADC_arr[arrLength - 1]);

  int aver = 0;

  for(int i=arrLength/5; i<(arrLength - arrLength/5); i++) {
    aver += ADC_arr[i];
    // Serial.println(aver);
  }
  // Serial.println(arrLength-arrLength/5 - arrLength/5);
  return aver/(arrLength-arrLength/5 - arrLength/5);

  // for(int i=2; i<=7; i++) {
  //   aver += ADC_arr[i];
  //   Serial.println(aver);
  // }
  // Serial.println(aver/6);
  // return aver / 6;
}