#include <LiquidCrystal.h>
#include <JC_Button.h>
 
const float Low_BAT_level = 3.2;
 11
//Current steps with a 3R load (R7)
const int Current[] = {0, 37, 70, 103, 136, 169, 202, 235, 268, 301, 334, 367, 400, 440, 470, 500, 540};
 
const byte RS = 2, EN = 3, D4 = 4, D5 = 5, D6 = 6, D7 = 7;
const byte PWM_Pin = 10;
const byte Speaker = 12;
const int BAT_Pin = A0;
int PWM_Value = 0;
unsigned long Capacity = 0;
int ADC_Value = 0;
float BAT_Voltage = 0;
byte Hour = 0, Minute = 0, Second = 0;
bool calc = false, Done = false;
 
LiquidCrystal lcd(RS, EN, D4, D5, D6, D7);
 
Button UP_Button(16, 25, false, true);
Button Down_Button(15, 25, false, true);
 
void setup() {
 
 pinMode(PWM_Pin, OUTPUT);
 pinMode(Speaker, OUTPUT);
 
 analogWrite(PWM_Pin, PWM_Value);
 
 UP_Button.begin();
 Down_Button.begin();
 
 lcd.setCursor(0, 0);
 lcd.begin(16, 2);
 lcd.print("Battery Capacity");
 lcd.setCursor(0, 1);
 lcd.print("Measurement v1.0");
 delay(3000);
 lcd.clear();
 lcd.print("Load Adj:UP/Down");
 lcd.setCursor(0, 1);
 lcd.print("0");
 
}
 
void loop() {
 
 UP_Button.read();
 Down_Button.read();
 
 if (UP_Button.wasReleased() && PWM_Value < 80 && calc == false)
 {
  PWM_Value = PWM_Value + 5;
  analogWrite(PWM_Pin, PWM_Value);
  lcd.setCursor(0, 1);
  lcd.print("   ");
  lcd.setCursor(0, 1);
  lcd.print(String(Current[PWM_Value / 5]) + "mA");
 }
 
 if (Down_Button.wasReleased() && PWM_Value > 1 && calc == false)
 {
  PWM_Value = PWM_Value - 5;
  analogWrite(PWM_Pin, PWM_Value);
  lcd.setCursor(0, 1);
  lcd.print("   ");
  lcd.setCursor(0, 1);
  lcd.print(String(Current[PWM_Value / 5]) + "mA");
 }
 
 if (UP_Button.pressedFor(1000) && calc == false)
 {
  digitalWrite(Speaker, HIGH);
  delay(100);
  digitalWrite(Speaker, LOW);
  lcd.clear();
  timerInterrupt();
 }
 
}
 
void timerInterrupt() {
 calc = true;
 while (Done == false) {
  Second ++;
  if (Second == 60) {
   Second = 0;
   Minute ++;
   lcd.clear();
  }
  if (Minute == 60) {
   Minute = 0;
   Hour ++;
  }
  lcd.setCursor(0, 0);
  lcd.print(String(Hour) + ":" + String(Minute) + ":" + String(Second));
  lcd.setCursor(9, 0);
  ADC_Value = analogRead(BAT_Pin);
  BAT_Voltage = ADC_Value * (5.0 / 1024);
  lcd.print("V:" + String(BAT_Voltage));
  lcd.setCursor(0, 1);
  lcd.print("BAT-C: Wait!...");
 
  if (BAT_Voltage < Low_BAT_level)
  {
   lcd.setCursor(0, 1);
   lcd.print("        ");
   lcd.setCursor(0, 1);
   Capacity = (Hour * 3600) + (Minute * 60) + Second;
   Capacity = (Capacity * Current[PWM_Value / 5]) / 3600;
   lcd.print("BAT-C:" + String(Capacity) + "mAh");
   Done = true;
   PWM_Value = 0;
   analogWrite(PWM_Pin, PWM_Value);
   digitalWrite(Speaker, HIGH);
   delay(100);111
   digitalWrite(Speaker, LOW);
   delay(100);
   digitalWrite(Speaker, HIGH);
   delay(100);
   digitalWrite(Speaker, LOW);
  }
 
  delay(1000);
 }
}