//#include <math.h>  

#define PIN_SENSOR_PHRESISTOR 34

// valores de la formula AJUSTE LINEAL
#define A   1.0f
#define B   1.0f

// Variable globales : declaracion
 float V_LDR;

// declaracion de funciones
void configADC(uint8_t pin);
void phtr_medicion(uint8_t valorADC);

void setup() {  
  Serial.begin(115200);
  //pinMode( PIN_SENSOR_PHRESISTOR , INPUT);
  Serial.printf("\n Lectura de valor en PIN( %i )", PIN_SENSOR_PHRESISTOR);
  configADC( PIN_SENSOR_PHRESISTOR );
   
}  
 
void loop() {  

  phtr_medicion( PIN_SENSOR_PHRESISTOR );

  //Serial.printf("\n Resistencia = %5.3f Ohmios", phtr_valor  );
  delay(500);  
}  

/********
 * FUNCIONES DE MEDICION
 ********/
 
void phtr_medicion( uint8_t pin ) {
  // funcion para ajsute de la medida a voltios ( puede ajustarse a irradiacion luminica )
 
  static uint16_t entradaADC; // valor de la tensión de entrada en el pin => ADC
 
  entradaADC = analogRead(pin);

  //Mapeo de tension 
  float V_LDR = entradaADC * (3.3 / 4095.0);

  //Mapeo de % 
  float porcentaje = entradaADC * (100 / 4095.0);

  //

  Serial.printf("\n valor \t ADC = %5i ", entradaADC );
  Serial.printf("\n valor \t Tensión = %.3f ", V_LDR );
   Serial.printf("\n valor \t Porcentaje = %.3f \n", porcentaje );
 
}  

/********
 * FUNCIONES DE CONFIGURACION ENTRADAS ADC
 ********/

void configADC(uint8_t pin = 0 ){
  /* analogReadResolution(resolution): set the sample bits and resolution.
  It can be a value between 9 (0 – 511) and 12 bits (0 – 4095). Default is 12-bit resolution.
  */
  analogReadResolution(12);

  /* analogSetWidth(width): set the sample bits and resolution.
   It can be a value between 9 (0 – 511) and 12 bits (0 – 4095).Default is 12-bit resolution.
  */
  analogSetWidth(12);

  /* analogSetCycles(cycles): set the number of cycles per sample.
   *  Default is 8. Range: 1 to 255.
  */
  //analogSetCycles(8);
 
  /*analogSetSamples(samples): set the number of samples in the range.
   * Default is 1 sample. It has an effect of increasing sensitivity.
  */
 // analogSetSamples(2);

  /* analogSetClockDiv(attenuation): set the divider for the ADC clock.
   * Default is 1. Range: 1 to 255.
  */
  analogSetClockDiv(1);
 
 /*analogSetAttenuation(attenuation): sets the input attenuation for all ADC pins. Default is ADC_11db. Accepted values:
    ADC_0db  : sets no attenuation. ADC can measure up to approximately 800 mV (1V input = ADC reading of 1088).
    ADC_2_5db: The input voltage of ADC will be attenuated, extending the range of measurement to up to approx. 1100 mV. (1V input = ADC reading of 3722).
    ADC_6db  : The input voltage of ADC will be attenuated, extending the range of measurement to up to approx. 1350 mV. (1V input = ADC reading of 3033).
    ADC_11db : The input voltage of ADC will be attenuated, extending the range of measurement to up to approx. 2600 mV. (1V input = ADC reading of 1575).
*/
  //analogSetAttenuation(ADC_11db);
 
  /* analogSetPinAttenuation(pin, attenuation): sets the input attenuation for the specified pin.
   *  The default is ADC_11db. Attenuation values are the same from previous function.
  */
  if ( pin != 0 )  analogSetPinAttenuation(pin, ADC_11db);
 
  /* adcAttachPin(pin): Attach a pin to ADC (also clears any other analog mode that could be on).
   * Returns TRUE or FALSE result.
   */
   if ( pin != 0 ) {
    if ( adcAttachPin(pin) ){
      Serial.printf( "\n\n PIN ( %i ) CONECTADO AL ADC ", pin);
    }
    else{
      Serial.printf( "\n\n PIN ( %i ) NO CONECTADO AL ADC ", pin);
    }
  }
   
  /*adcStart(pin), adcBusy(pin) and resultadcEnd(pin): starts an ADC convertion on attached pin’s bus. Check if conversion on the pin’s ADC bus is currently running (returns TRUE or FALSE). Get the result of the conversion: returns 16-bit integer.
*/
}