/*
O número de bandas é calculado conforme aumentamos Bandas[], Fmin[] e Fmax[]
*/

#include <Wire.h> 
#include <LiquidCrystal_I2C.h>

#define INC 2
#define DEC 3
#define BAND 4

LiquidCrystal_I2C lcd(0x27, 20, 4);  // set the LCD address to 0x27 for a 16 chars and 2 line display

String Bandas[] = {"160m", "80m", "40m", "20m", "15m", "10m", "6m", "2m"};
unsigned long Fmin[] = {1800000, 3500000, 7000000, 14000000, 21000000, 28000000, 50000000, 144000000};
unsigned long Fmax[] = {2000000, 4000000, 7300000, 14300000, 21500000, 28300000, 54000000, 148000000};

bool FBAND;
int tec, i;
unsigned long F, STEP;

void setup(){

  pinMode(INC, INPUT);
  pinMode(DEC, INPUT);

  lcd.init();
  lcd.backlight();

  lcd.setCursor(0,0);
  lcd.print("Frequencia:");

  i = 0;
  STEP = 100000;
  FBAND = true;
}

void loop(){

  lcd.setCursor(11,3);
  lcd.print("NBandas:");
  lcd.print(sizeof(Bandas)/sizeof(Bandas[0]));

  lcd.setCursor(0,1);
  lcd.print("    ");

  lcd.setCursor(0,1);
  lcd.print(Bandas[i]);

  if(FBAND){
    F = Fmin[i];
    FBAND = false;
  }

  lcd.setCursor(0,2);
  lcd.print("        ");

  lcd.setCursor(0,2);
  lcd.print(F);

  lcd.setCursor(0,3);
  lcd.print(STEP); 

  tec = le_teclas();
  //Incrementa frequência
  if(tec == 1){
    
    F = F + STEP;

    if(F > Fmax[i])
      F = Fmax[i];
  }
  //Decrementa frequência
  else if(tec == 2){
  
    F = F - STEP;

    if(F < Fmin[i])
      F = Fmin[i];

  }
  //Altera banda
  else if(tec == 3){
    
    i++;

    if(i > (sizeof(Bandas)/sizeof(Bandas[0]))-1)
      i = 0;
    
    FBAND = true;
  }
}

int le_teclas(void){

  int tecla = 0;

  do{
    
    if(digitalRead(INC) == 0){
      tecla = 1;
    }
    else if(digitalRead(DEC) == 0){
      tecla = 2;
    }    
    else if(digitalRead(BAND) == 0){
      tecla = 3;
    }     

  }while(tecla == 0);

  delay(400);

  return tecla;
}