#include <LiquidCrystal.h>
LiquidCrystal lcd(8,9,4,5,6,7);
//This program will show a simple menu of car data: rpm, speed, temperature and consumption.
int lcd_key=0;
int adc_key_in=0, menuPos=0,menuPosc;
String initMssg="Intentando conectar con el vehiculo...";
String temperatureMssg="Ext. temp: ",rpmMssg="r.p.m.:", speedMssg="speed:",consumptionMssg="consumption:", noFunctionMssg="este boton no tiene funcion asignada,",okMssg="conectado con coche";
#define btnRIGHT  0
#define btnUP     1
#define btnDOWN   2
#define btnLEFT   3
#define btnSELECT 4
#define btnNONE   5
#define BUTTON_ADC_PIN  A0      // A0 is the button ADC input
#define LCD_BACKLIGHT_PIN         3  // D3 controls LCD backlight
boolean firstTime=true;
void setup(){
  pinMode(BUTTON_ADC_PIN,INPUT);         //ensure A0 is an input
  digitalWrite(BUTTON_ADC_PIN,LOW);      //ensure pullup is off on A0
  //lcd backlight control
  digitalWrite( LCD_BACKLIGHT_PIN, HIGH );  //backlight control pin D3 is high (on)
  pinMode( LCD_BACKLIGHT_PIN, OUTPUT );     //D3 is an output
  lcd.begin(16,2);
  lcd.setCursor(0,0);

  lcd.print(initMssg);
  showMessage(initMssg);
  lcd.clear();
  Serial.begin(9600);
}
void loop(){
  if(firstTime){
    lcd.clear();
    lcd.print(okMssg);
    showMessage(okMssg);
    firstTime=false;
    menuPosc=menuPos;
  }
  switch(read_KeypadBttn()){
  case btnUP:
    menuPos++;
    Serial.println("boton up pulsado");
    delay(170);
    break;
  case btnDOWN:
    delay(170);
    menuPos--;
    Serial.println("boton down pulsado");
    break;
  }
  if(menuPosc!=menuPos){
    printMenu();
  }
}

void printMenu(){

  if(menuPos<4){
    menuPos=menuPos+4;
  }
  lcd.clear();
  switch(menuPos%4){
  case 0:
    lcd.print(temperatureMssg);
    lcd.setCursor(0,1);

    lcd.print(rpmMssg);
    break;
  case 1:
    lcd.print(rpmMssg);
    lcd.setCursor(0,1);

    lcd.print(speedMssg);
    break;
  case 2:
    lcd.print(speedMssg);
    lcd.setCursor(0,1);

    lcd.print(consumptionMssg);
    break;
  case 3:
    lcd.print(consumptionMssg);
    lcd.setCursor(0,1);
    lcd.print(temperatureMssg);
    break;

  }
  delay(5);
}

int read_KeypadBttn(){
  adc_key_in=analogRead(0); //read the value from analog input 0
  //using the concept of voltage divider and analog input resolution 10 bits
  // For V1.1 us this threshold
  if(adc_key_in>1000) {
    return btnNONE;
  }
  else if (adc_key_in < 50){
    return btnRIGHT;
  }
  else if (adc_key_in < 250){
    return btnUP;
  }
  else if (adc_key_in < 450){
    return btnDOWN;
  }
  else if (adc_key_in < 650) {
    return btnLEFT;
  }
  else if (adc_key_in < 850){
    return btnSELECT;
  }
  else{
    return btnNONE;//if the others fail
  }

}
void showMessage(String message){
  if(message.length()>16){
    for(int i=0;i<message.length()-16;i++){
      lcd.scrollDisplayLeft();
      delay(500);
    }
  }
}