#include <Wire.h>
#include <Adafruit_ADS1015.h>

// ADS1115 addresses: (GND - 0x48) (SDA 0x4A)
Adafruit_ADS1115 ads1(0x48);  /* Use this for the 16-bit version */
Adafruit_ADS1115 ads2(0x4A);  /* Use this for the 16-bit version */

void setup(void)
{
  // Serial monitor
  Serial.begin(9600);
  Serial.println("Hello!");

  ads1.setGain(GAIN_ONE);        // 1x gain   +/- 4.096V  1 bit = 2mV      0.125mV
  ads2.setGain(GAIN_ONE);        // 1x gain   +/- 4.096V  1 bit = 2mV      0.125mV
  ads1.begin();
  ads2.begin();
}

void loop(void)
{
  // ADC reading 
  int16_t adc1_0, adc1_1, adc1_2, adc1_3; // FIRST ADC
  int16_t adc2_0, adc2_1, adc2_2, adc2_3; // SECOND ADC

  // Read from first ADC
  adc1_0 = ads1.readADC_SingleEnded(0);
  adc1_1 = ads1.readADC_SingleEnded(1);
  adc1_2 = ads1.readADC_SingleEnded(2);
  adc1_3 = ads1.readADC_SingleEnded(3);

  // Read from second ADC
  adc2_0 = ads2.readADC_SingleEnded(0);
  adc2_1 = ads2.readADC_SingleEnded(1);
  adc2_2 = ads2.readADC_SingleEnded(2);
  adc2_3 = ads2.readADC_SingleEnded(3);


  // Average values in time
  double avg_bits_1_0 = 0; // Setpoint Mass flow controller
  double avg_bits_1_1 = 0; // Output Mass flow controller

  double avg_bits_2_0 = 0; // Output 10 Torr pressure gauge
  
  int Navg = 250;
  
  for(int ii = 0; ii < Navg; ++ii)
  {
    avg_bits_1_0 += (double)(adc1_0)/Navg;
    avg_bits_1_1 += (double)(adc1_1)/Navg;

    avg_bits_2_0 += (double)(adc2_0)/Navg;
  }

  // Convert to voltages
  double Vsetpoint_mV = avg_bits_1_0*0.125; // Setpoint voltage Mass flow controller
  double Voutput_mV   = avg_bits_1_1*0.125; // Output voltage Mass flow controller

  double Voutput_mV_Pressure = avg_bits_2_0*0.125; // Output voltage pressure gauge (divided by two)
  double P_Torr = Voutput_mV_Pressure/1000/5*10;
  
  Serial.print("\n");
  Serial.print("Setpoint - He: "); Serial.print(Vsetpoint_mV); Serial.print(" mV  "); Serial.print(Vsetpoint_mV/1000*30/5); Serial.print(" sccm\n"); // "30" -> 30sccm FS mass flow controller
  Serial.print("Output   - He: "); Serial.print(Voutput_mV);   Serial.print(" mV  "); Serial.print(Voutput_mV/1000*30/5);   Serial.print(" sccm\n"); // "30" -> 30sccm FS mass flow controller

  Serial.print("\n");
  Serial.print("P: "); Serial.print(Voutput_mV_Pressure); Serial.print(" mV  "); Serial.print(P_Torr); Serial.print(" Torr   =   "); Serial.print(P_Torr*133); Serial.print(" Pa\n");

  delay(1000);
}