#include <JC_Button.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)
#define OLED_RESET     4 // Reset pin # (or -1 if sharing Arduino reset pin)
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);


const float Low_BAT_level = 3.0;
//Current steps with a 3R load (R7)
const int Current [] = {0,110,210,300,390,490,580,680,770,870,960,1000};
const byte PWM_Pin = 10;
const byte Buzzer = 9;
const int BAT_Pin = A0;
int PWM_Value = 0;
unsigned long Capacity = 0;
int ADC_Value = 0;
float Vcc = 4.96 ; // Voltage of Arduino 5V pin ( Mesured by Multimeter )
float BAT_Voltage = 0;
float sample =0;
byte Hour = 0, Minute = 0, Second = 0;
bool calc = false, Done = false;
Button UP_Button(2, 25, false, true);
Button Down_Button(3, 25, false, true);


void setup () {
//
Serial.begin(9600);
pinMode(PWM_Pin, OUTPUT);
pinMode(Buzzer, OUTPUT);
analogWrite(PWM_Pin, PWM_Value);
UP_Button.begin();
Down_Button.begin();
display.begin(SSD1306_SWITCHCAPVCC, 0x3C);
display.clearDisplay();
display.setTextColor(WHITE); 
display.setTextSize(1);
display.setCursor(12,25);
display.print("Open Green Energy");
display.display();  
delay(3000);
display.clearDisplay();
display.setTextSize(2);
display.setCursor(2,15);
display.print("Adj Curr:"); 
display.setCursor(2,40);
display.print("UP/Down:");
display.display(); 
delay(3000);
display.print("0");
display.display();  
}

//************************* End of Setup function *******************************

void loop() {
  UP_Button.read();
  Down_Button.read();
if (UP_Button.wasReleased() && PWM_Value < 55 && calc == false)
 {
  PWM_Value = PWM_Value + 5; 
  analogWrite(PWM_Pin,PWM_Value);


  
  display.clearDisplay();
  display.setCursor(2,25);
  display.print("Curr:");   
  display.print(String(Current[PWM_Value / 5])+"mA");
  display.display();  
//  Serial.println(String(Current[PWM_Value / 5]));
 }
if (Down_Button.wasReleased() && PWM_Value > 1 && calc == false)
{ 
  PWM_Value = PWM_Value - 5; 
  analogWrite(PWM_Pin,PWM_Value); 
  display.clearDisplay();
  display.setCursor(2,25);
  display.print("Curr:");   
  display.print(String(Current[PWM_Value / 5])+"mA");
  display.display();  
 // Serial.println(String(Current[PWM_Value / 5]) + "mA");
  
} 

if (UP_Button.pressedFor (1000) && calc == false)
{
  digitalWrite(Buzzer, HIGH);
  delay(100);
  digitalWrite(Buzzer, LOW);
  display.clearDisplay();
  timerInterrupt(); 
   
  }
}

//************************* End of Loop function *******************************

void timerInterrupt(){
  calc = true;
  while (Done == false)  {
     Second ++;
    if (Second == 60)  {
      Second = 0;
      Minute ++;      
    }
    if (Minute == 60)  {
      Minute = 0;
      Hour ++;
    }

 //************ Measuring Battery Voltage ***********
  
  for(int i=0;i< 100;i++)
  {
   sample=sample+analogRead(BAT_Pin); //read the Battery voltage 
   delay (2);
  }
  sample=sample/100; 
  BAT_Voltage = sample * Vcc/ 1024.0; 
 
  //*********************************************

    display.clearDisplay();
    display.setTextSize(2);
    display.setCursor(20,5);
    display.print(String(Hour) + ":" + String(Minute) + ":" + String(Second));

    display.setTextSize(1);
    display.setCursor(0,25);
    display.print("Disch Curr: ");   
    display.print(String(Current[PWM_Value / 5])+"mA");
     
    
    display.setCursor(2,40);   
    display.print("Bat Volt:" + String(BAT_Voltage)+"V" );



    Capacity =  (Hour * 3600) + (Minute * 60) + Second;
    Capacity = (Capacity * Current[PWM_Value / 5]) / 3600;
    display.setCursor(2, 55);
    display.print("Capacity:" + String(Capacity) + "mAh");
    display.display();

    
    if (BAT_Voltage < Low_BAT_level)
    {
      Capacity =  (Hour * 3600) + (Minute * 60) + Second;
      Capacity = (Capacity * Current[PWM_Value / 5]) / 3600;
      display.clearDisplay(); 
      display.setTextSize(2);      
      display.setCursor(2,15);     
      display.print("Capacity:");
      display.setCursor(2,40);  
      display.print(String(Capacity) + "mAh");
      display.display();
      Done = true;
      PWM_Value = 0;
      analogWrite(PWM_Pin, PWM_Value);
      digitalWrite(Buzzer, HIGH);
      delay(100);
      digitalWrite(Buzzer, LOW);
      delay(100);
      digitalWrite(Buzzer, HIGH);
      delay(100);
      digitalWrite(Buzzer, LOW);
      delay(100);
    }
       delay(1000);
  } 
   
}