//Include library
#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
#define OLED_RESET     4 // Reset pin # (or -1 if sharing Arduino reset pin  
//Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT,OLED_RESET);

#define OLED_RESET 4
Adafruit_SSD1306 display(OLED_RESET);
#define DEF_PIN 14//A0
#define DEF_CONV_FACTOR 1.7
#define DEF_READS 20


/*
 * 18650 Ion-Li battery charge
 * Calculates charge level of an 18650 Ion-Li battery
 */
class Pangodream_18650_CL {    
  public:  
    
    /*
    * Constructor
    * @param addressPin, ADC pin number where the voltage divider is connected to
    */
    Pangodream_18650_CL(int addressPin);
    
    /*
    * Constructor
    * @param addressPin, ADC pin number where the voltage divider is connected to
    * @param convFactor, Convertion factor for analog read units to volts
    */
    Pangodream_18650_CL(int addressPin, double convFactor);
    
    /*
    * Constructor
    * @param addressPin, ADC pin number where the voltage divider is connected to
    * @param convFactor, Convertion factor for analog read units to volts
    * @param reads, Number of reads of analog pin to calculate an average value
    */
    Pangodream_18650_CL(int addressPin, double convFactor, int reads);
    /*
    * Constructor
    */
    Pangodream_18650_CL();    

    /*
     * Get the battery charge level (0-100)
     * @return The calculated battery charge level
     */
    int getBatteryChargeLevel();
    double getBatteryVolts();
    int getAnalogPin();
    int pinRead();
    double getConvFactor();
       
  private:

    int    _addressPin;               //!< ADC pin used, default is GPIO34 - ADC1_6
    int    _reads;                    //Number of reads of ADC pin to calculate an average value
    double _convFactor;               //!< Convertion factor to translate analog units to volts
    double _vs[101];                 //Array with voltage - charge definitions
    
    void   _initVoltsArray();
    int    _getChargeLevel(double volts);
    int    _analogRead(int pinNumber);
    double _analogReadToVolts(int readValue);
    
};


Pangodream_18650_CL::Pangodream_18650_CL(int addressPin, double convFactor, int reads)
{
    _reads = reads;
    _convFactor = convFactor;
    _addressPin = addressPin;
    _initVoltsArray();
}

Pangodream_18650_CL::Pangodream_18650_CL(int addressPin, double convFactor)
{
    _reads = DEF_READS;
    _convFactor = convFactor;
    _addressPin = addressPin;
    _initVoltsArray();
}

Pangodream_18650_CL::Pangodream_18650_CL(int addressPin)
{
    _reads = DEF_READS;
    _convFactor = DEF_CONV_FACTOR;
    _addressPin = addressPin;
    _initVoltsArray();
}

Pangodream_18650_CL::Pangodream_18650_CL()
{
    _reads = DEF_READS;
    _convFactor = DEF_CONV_FACTOR;
    _addressPin = DEF_PIN;
    _initVoltsArray();
}

int Pangodream_18650_CL::getAnalogPin()
{
    return _addressPin;
}
double Pangodream_18650_CL::getConvFactor()
{
    return _convFactor;
}
    
/**
 * Loads each voltage value in its matching charge element (index)
 */
void Pangodream_18650_CL::_initVoltsArray(){
    _vs[0] = 2.640; 
    _vs[1] = 2.645; _vs[2] = 2.650; _vs[3] = 2.655; _vs[4] = 2.660; _vs[5] = 2.665;
    _vs[6] = 2.670; _vs[7] = 2.675; _vs[8] = 2.680; _vs[9] = 2.685; _vs[10] = 2.690;
    _vs[11] = 2.695; _vs[12] = 2.700; _vs[13] = 2.705; _vs[14] = 2.710; _vs[15] = 2.715;
    _vs[16] = 2.720; _vs[17] = 2.725; _vs[18] = 2.730; _vs[19] = 2.735; _vs[20] = 2.740;
    _vs[21] = 2.745; _vs[22] = 2.750; _vs[23] = 2.755; _vs[24] = 2.760; _vs[25] = 2.765;
    _vs[26] = 2.770; _vs[27] = 2.775; _vs[28] = 2.780; _vs[29] = 2.785; _vs[30] = 2.790;
    _vs[31] = 2.795; _vs[32] = 2.800; _vs[33] = 2.805; _vs[34] = 2.810; _vs[35] = 2.815;
    _vs[36] = 2.820; _vs[37] = 2.825; _vs[38] = 2.830; _vs[39] = 2.835; _vs[40] = 2.840;
    _vs[41] = 2.845; _vs[42] = 2.850; _vs[43] = 2.855; _vs[44] = 2.860; _vs[45] = 2.865;
    _vs[46] = 2.870; _vs[47] = 2.875; _vs[48] = 2.880; _vs[49] = 2.885; _vs[50] = 2.890;
    _vs[51] = 2.895; _vs[52] = 2.900; _vs[53] = 2.905; _vs[54] = 2.910; _vs[55] = 2.915;
    _vs[56] = 2.920; _vs[57] = 2.925; _vs[58] = 2.930; _vs[59] = 2.935; _vs[60] = 2.940;
    _vs[61] = 2.945; _vs[62] = 2.950; _vs[63] = 2.955; _vs[64] = 2.960; _vs[65] = 2.965;
    _vs[66] = 2.970; _vs[67] = 2.975; _vs[68] = 2.980; _vs[69] = 2.985; _vs[70] = 2.990;
    _vs[71] = 2.995; _vs[72] = 3.000; _vs[73] = 3.005; _vs[74] = 3.010; _vs[75] = 3.015;
    _vs[76] = 3.020; _vs[77] = 3.025; _vs[78] = 3.030; _vs[79] = 3.035; _vs[80] = 3.040;
    _vs[81] = 3.045; _vs[82] = 3.050; _vs[83] = 3.055; _vs[84] = 3.060; _vs[85] = 3.065;
    _vs[86] = 3.070; _vs[87] = 3.075; _vs[88] = 3.080; _vs[89] = 3.095; _vs[90] = 3.100;
    _vs[91] = 3.105; _vs[92] = 3.110; _vs[93] = 3.115; _vs[94] = 3.120; _vs[95] = 3.125;
    _vs[96] = 3.130; _vs[97] = 3.135; _vs[98] = 3.140; _vs[99] = 3.145; _vs[100] = 3.150;
}

int Pangodream_18650_CL::getBatteryChargeLevel()
{
    int readValue = _analogRead(_addressPin);
    double volts = _analogReadToVolts(readValue);
    int chargeLevel = _getChargeLevel(volts);
    return chargeLevel;
}

int Pangodream_18650_CL::pinRead(){
    return _analogRead(_addressPin); 
}

int Pangodream_18650_CL::_analogRead(int pinNumber){
    int totalValue = 0;
    int averageValue = 0;
    for(int i = 0; i < _reads; i++){
       totalValue += analogRead(pinNumber);
    }
    averageValue = totalValue / _reads;
    return averageValue; 
}
/**
 * Performs a binary search to find the index corresponding to a voltage.
 * The index of the array is the charge %
*/
int Pangodream_18650_CL::_getChargeLevel(double volts){
  int idx = 50;
  int prev = 0;
  int half = 0;
  if (volts >= 3.150){
    return 100;
  }
  if (volts <= 2.640){
    return 0;
  }
  while(true){
    half = abs(idx - prev) / 2;
    prev = idx;
    if(volts >= _vs[idx]){
      idx = idx + half;
    }else{
      idx = idx - half;
    }
    if (prev == idx){
      break;
    }
  }
  return idx;
}

double Pangodream_18650_CL::_analogReadToVolts(int readValue){
  double volts; 
  volts = readValue * (5.00 / 1023.00) * 2;
  //volts = readValue * _convFactor / 1000;
  return volts;
}

double Pangodream_18650_CL::getBatteryVolts(){
    int readValue = analogRead(_addressPin);
    return _analogReadToVolts(readValue);
}
Pangodream_18650_CL BL;

int h = 2;
int m = 0;
int s = 0;
int flag = 0;
int TIME = 0;
const int hs = 0;
const int ms = 1;
int state1 = 0;
int state2 = 0;

int Counter =0; //Simple Counter Loop (See Below to Close Loop)

void setup()
{
    Serial.begin(9600);
    //Initialize display by providing the display type and its I2C address.
    display.begin(SSD1306_SWITCHCAPVCC, 0x3C);

    //Set the text size and color.
    display.setTextSize(1);
    display.setTextColor(WHITE);
}

void loop()
{
  
  int sensorValue = analogRead(A0);
  unsigned long voltageInMv = sensorValue * 5000UL;
  
    printVolts();
  s = s + 1;
  
    
  delay(1000);
  //display.clear();
  if (s == 60)
  {
    s = 0;
    m = m + 1;
  }
  if (m == 60)
  {
    m = 0;
    h = h + 1;
    flag = flag + 1;
  }
  if (h == 13)
  {
    h = 1;
  }
    
  state1 = digitalRead(hs);
  if (state1 == 0)
  {
    h = h + 1;
    flag = flag + 1;
    if (h == 13) h = 1;
  }
  state2 = digitalRead(ms);
  if (state2 == 0)
  {
    s = 0;
    m = m + 1;
  }
    //Clear previous image.
    display.clearDisplay();

    display.setCursor(25, 10);
    //display.print("Hello World.");
    display.print("Time:");
    display.print(h);
    display.print(":");
    display.print(m);
    display.print(":");
    display.print(s);
    if (flag < 12) display.print("AM");
    if (flag == 12) display.print(" PM");
    if (flag > 12) display.print(" PM");
    if (flag == 24) flag = 0;
    //display.println();
    //display.println();
    display.setCursor(25,20);
    display.print("V=");
    display.print(BL.getBatteryVolts());
    display.print("V");
    display.print(" H=");
    display.print(BL.getBatteryChargeLevel());
    display.print("%");
   //if (voltage < 2.25) //set the voltage considered low battery here
    
    //Display changes if any were made.
    display.display();
    delay(1);
}
void printVolts()
{
  float voltage = analogRead(14) * (5.00 / 1023.00) * 2; //convert the value to a true voltage.
  int sensorValue = analogRead(14); //read the A0 pin value
  //float voltage = sensorValue * (5.00 / 1023.00) * 2; //convert the value to a true voltage.
  display.setCursor(0, 0);
  display.print("Time:");
  display.print(h);
  display.print(":");
  display.print(m);
  display.print(":");
  display.print(s);
  if (flag < 12) display.print("AM");
  if (flag == 12) display.print(" PM");
  if (flag > 12) display.print(" PM");
  if (flag == 24) flag = 0;
  display.println();
  display.print("V=");
  display.print(voltage); //print the voltage to LCD
  display.print("V");
  display.print(" H=");
  display.print(BL.getBatteryChargeLevel());
  display.print("%");
  if (voltage < 6.50) //set the voltage considered low battery here
  
  // Serial print time.
  //Serial.print("Time:");
  Serial.print(h);
  Serial.print(":");
  Serial.print(m);
  Serial.print(":");
  Serial.print(s);
  if (flag < 12) Serial.print("AM");
  if (flag == 12) Serial.print("PM");
  if (flag > 12) Serial.print("PM");
  if (flag == 24) flag = 0;
      
  // Serial print voltage.
  //Serial.println(analogRead(14));
  //Serial.print("Average value from pin: ");
  Serial.print(" ,voltage,");
  Serial.print(voltage); //print the voltage to serial
  Serial.print("V");
  Serial.print(",Charge level,");
  Serial.print(BL.getBatteryChargeLevel());
  Serial.println("%");
  
   
  delay(1000);
{
   
  }
}