// frequencimetro de 60Hz
// Voltimetro

#include <LiquidCrystal.h>
LiquidCrystal lcd(13,12,11,10,9,8);
long freq, tempo, TOld, TNew;

#define resistance_R500 1000000
#define resistance_V2 10000
#define caliberation_V2 1.05
#define range500_mul (resistance_R500 / resistance_V2) * caliberation_V2
#define resistance_R2 1000

int adc_value = 0;
int voltage_peak_value = 0;
float voltage_average_value = 0;
float dc_voltage_V0 = 0;
int ac_voltage_V0 = 0;
unsigned long sample_count = 0;

void setup()
{
  Serial.begin(9600);
  pinMode(2,INPUT);
  lcd.begin(20, 2);
  lcd.setCursor(3,0);
  lcd.print("FREQUENCIMETRO");
  Serial.print("FREQUENCIMETRO");
  attachInterrupt(0, frequencia, RISING);
}

void loop()
{
 voltagem();
 delay(20);
}

//=============================== VOLTAGE ========================================//
void voltagem()
{
  voltage_peak_value = 0;
  for(sample_count = 0; sample_count < 500; sample_count ++)
  {
    adc_value = analogRead(A1);
    if(voltage_peak_value < adc_value)
    voltage_peak_value = adc_value;
    else;
    delayMicroseconds(1);
  }
  dc_voltage_V0 = voltage_peak_value * 0.00488;
  ac_voltage_V0 = (dc_voltage_V0 / 1.414) * range500_mul;
  lcd.setCursor(0,0);
  Serial.print("V");
  lcd.setCursor(3,0);
  Serial.println(ac_voltage_V0);
}

//=============================== FREQUENCY ========================================//
void frequencia()
{
   tempo = micros();
   TOld = tempo - TNew;
   TNew = tempo;
   freq = (10000000/TOld)+5;        // +5 correção de erro de divisão

   lcd.setCursor(7,1);
   Serial.print(freq/10);
   lcd.setCursor(13,1);
   Serial.println("Hz");
}