#include <LiquidCrystal.h>

#define gatePin 8
#define highPin A5
#define lowPin A4

float mAh = 0.0;
float shuntRes = 5.3;
float voltRef = 4.89; // AREF Spannung
float current = 0.0;
float battVolt = 0.0;
float shuntVolt = 0.0;
float battLow = 2.9;
float battHigh = 4.3;
boolean cellOkay = false;

float sample1 = 0;
float sample2 = 0;

unsigned long previousMillis = 0;
unsigned long millisPassed = 0;
unsigned long started = 0;
unsigned long finished = 0;

unsigned long hour = 0;
unsigned long minute = 0;
unsigned long second = 0;
unsigned long time_target = 0;
char timeBuffer[11];

unsigned int delayTime = 0;

LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

byte batStat0[8] = {
  0b01110,
  0b10001,
  0b10001,
  0b10001,
  0b10001,
  0b10001,
  0b10001,
  0b11111
};

byte batStat2[8] = {
  0b01110,
  0b10001,
  0b10001,
  0b10001,
  0b10001,
  0b11111,
  0b11111,
  0b11111
};

byte batStat4[8] = {
  0b01110,
  0b10001,
  0b10001,
  0b11111,
  0b11111,
  0b11111,
  0b11111,
  0b11111
};


byte batStat6[8] = {
  0b01110,
  0b11111,
  0b11111,
  0b11111,
  0b11111,
  0b11111,
  0b11111,
  0b11111
};


byte batWrench[8] = {
  0b01110,
  0b11111,
  0b10101,
  0b10001,
  0b11011,
  0b11011,
  0b11111,
  0b11111
};


byte batWarning[8] = {
  0b01110,
  0b10001,
  0b10001,
  0b10001,
  0b11011,
  0b11111,
  0b11011,
  0b11111
};

byte chargeplug[8] = {
  0b01010,
  0b01010,
  0b11111,
  0b10001,
  0b11111,
  0b00100,
  0b00100,
  0b00011
};

void setup() {
  Serial.begin(9600);
  Serial.println("Starting...");

  pinMode(gatePin, OUTPUT);
  digitalWrite(gatePin, LOW);

  lcd.begin(16, 2);

  lcd.createChar(0, batStat0);
  lcd.createChar(1, batStat2);
  lcd.createChar(2, batStat4);
  lcd.createChar(3, batStat6);
  lcd.createChar(4, batWrench);
  lcd.createChar(5, batWarning);
  lcd.createChar(6, chargeplug);

  lcd.setCursor(2, 0);
  lcd.print("LiIon Tester");
  lcd.setCursor(0, 1);
  lcd.print("gurkengewuerz.de");

  delay(2000);
  lcd.setCursor(0, 1);
  lcd.print("Bitte Warten    ");
  lcd.setCursor(12, 1);
  delay(500);
  lcd.write(".");
  delay(500);
  lcd.write(".");
  delay(500);
  lcd.write(".");
  delay(1000);

  lcd.clear();
}

void draw() {
  lcd.setCursor(0, 0);

  char str_battVolt[6];
  dtostrf(battVolt, 3, 2, str_battVolt);
  lcd.print(str_battVolt);
  lcd.print("V ");

  if (battVolt < 1 && !cellOkay) {
    lcd.setCursor(15, 0);
    lcd.write(byte(5));
    lcd.setCursor(0, 1);
    lcd.print(" KEINE BATTERIE ");
  } else if (battVolt > battHigh && !cellOkay) {
    lcd.setCursor(15, 0);
    lcd.write(byte(6));
    lcd.setCursor(0, 1);
    lcd.print("MAXIMAL SPANNUNG");
  } else if (battVolt < battLow && !cellOkay) {
    lcd.setCursor(15, 0);
    lcd.write(byte(0));
    lcd.setCursor(0, 1);
    lcd.print("GERINGE SPANNUNG");
  } else {
    char str_current[6];
    dtostrf(current, 3, 2, str_current);
    lcd.print(str_current);
    lcd.print("A    ");

    // Hinweis geben, wenn Zelle leer ist
    if (finished > 0)
      lcd.write(byte(0));
    else
      lcd.write(byte(6));



    lcd.setCursor(0, 1);

    if (finished > 0)
      time_target = finished;
    else
      time_target = (millis() / 1000) - started;


    hour = time_target / 3600;
    second = time_target % 3600;
    minute = second / 60;
    second %= 60;

    if (hour < 10) {
      lcd.print("0");
    }
    lcd.print(hour);
    lcd.print(":");
    if (minute < 10) {
      lcd.print("0");
    }
    lcd.print(minute);
    lcd.print(":");
    if (second < 10) {
      lcd.print("0");
    }
    lcd.print(second);
    lcd.write(" ");

    char str_mAh[6];
    dtostrf(mAh, 4, 0, str_mAh);
    lcd.print(str_mAh);
    lcd.print("mAh");
  }
}

void resetVals() {
  mAh = 0.0;
  current = 0.0;
  battVolt = 0.0;
  shuntVolt = 0.0;
  cellOkay = false;
  finished = 0;
  started = 0;

  sample1 = 0;
  sample2 = 0;

  previousMillis = 0;
  millisPassed = 0;
}

void loop() {
  for (int i = 0; i < 100; i++)
  {
    sample1 = sample1 + analogRead(highPin);
    delay (2);
  }
  sample1 = sample1 / 100;
  battVolt = 2 * sample1 * voltRef / 1024.0;


  for (int i = 0; i < 100; i++)
  {
    sample2 = sample2 + analogRead(lowPin);
    delay (2);
  }
  sample2 = sample2 / 100;
  shuntVolt = 2 * sample2 * voltRef / 1024.0;

  if ( battVolt > battHigh) {
    digitalWrite(gatePin, LOW);
    Serial.println("High Voltage");
    delayTime = 1000;
  } else if (battVolt < 1) {
    digitalWrite(gatePin, LOW);
    Serial.println("No Battery");
    resetVals(); // Nur Resetten der Variabeln, wenn keine Batterie drin ist (sonst wird nach der Messung das Display geleert!)
    delayTime = 1000;
  }  else if (battVolt < battLow) {
    digitalWrite(gatePin, LOW);
    Serial.println("Low Voltage");

    if (cellOkay && finished == 0) {
      finished = (millis() / 1000) - started;
    }

    delayTime = 1000;
  } else if (finished == 0) {
    digitalWrite(gatePin, HIGH);

    if (!cellOkay) {
      cellOkay = true;
      started = millis() / 1000;
    }

    millisPassed = millis() - previousMillis;
    current = (battVolt - shuntVolt) / shuntRes;
    mAh = mAh + (current * 1000.0) * (millisPassed / 3600000.0);
    previousMillis = millis();
    Serial.print(battVolt);
    Serial.print("\t");
    Serial.print(current);
    Serial.print("\t");
    Serial.println(mAh);
    delayTime = 4000;
  }

  draw();

  delay(delayTime);
}