/***************************************************************************
* Example sketch for the ADS1115_WE library
*
* This sketch shows how you can use the alert pin with the latch function. The 
* only difference to Alert_Window_Mode.ino is that latch is enabled (line 112) 
* and that the alert pin needs to be unlatched (line 148). Try and see the difference.
* As an alternative to the unlatchAlertPin function you can use getResult_V. 
* Internally unlatchAlertPin just performs a read of the conversion register.
*  
* Further information can be found on:
* https://wolles-elektronikkiste.de/ads1115
* 
***************************************************************************/

#include<ADS1115_WE.h> 
#include<Wire.h>
#define I2C_ADDRESS 0x48
volatile int interruptPin = 2;
int ledPin = 10;
volatile bool outOfLimit = false;

ADS1115_WE adc(I2C_ADDRESS);
// ADS1115_WE adc = ADS1115_WE(); // Alternative: sets default address 0x48

void setup() {
  Wire.begin();
  Serial.begin(9600);
  
  pinMode(interruptPin, INPUT_PULLUP);
  pinMode(ledPin, OUTPUT);
  digitalWrite(ledPin, LOW);
  
  if(!adc.init()){
    Serial.println("ADS1115 not connected!");
  }

  /* Set the voltage range of the ADC to adjust the gain
   * Please note that you must not apply more than VDD + 0.3V to the input pins!
   * 
   * ADS1115_RANGE_6144  ->  +/- 6144 mV
   * ADS1115_RANGE_4096  ->  +/- 4096 mV
   * ADS1115_RANGE_2048  ->  +/- 2048 mV (default)
   * ADS1115_RANGE_1024  ->  +/- 1024 mV
   * ADS1115_RANGE_0512  ->  +/- 512 mV
   * ADS1115_RANGE_0256  ->  +/- 256 mV
   */
  adc.setVoltageRange_mV(ADS1115_RANGE_6144); //comment line/change paramater to change range

  /* Set the inputs to be compared
   *  
   *  ADS1115_COMP_0_1    ->  compares 0 with 1 (default)
   *  ADS1115_COMP_0_3    ->  compares 0 with 3
   *  ADS1115_COMP_1_3    ->  compares 1 with 3
   *  ADS1115_COMP_2_3    ->  compares 2 with 3
   *  ADS1115_COMP_0_GND  ->  compares 0 with GND
   *  ADS1115_COMP_1_GND  ->  compares 1 with GND
   *  ADS1115_COMP_2_GND  ->  compares 2 with GND
   *  ADS1115_COMP_3_GND  ->  compares 3 with GND
   */
  adc.setCompareChannels(ADS1115_COMP_0_GND); //uncomment if you want to change the default

  /* Set number of conversions out of limit after which the alert pin will be active
   * - or you can disable the alert (including conversion ready alert)
   *  
   *  ADS1115_ASSERT_AFTER_1  -> after 1 conversion
   *  ADS1115_ASSERT_AFTER_2  -> after 2 conversions
   *  ADS1115_ASSERT_AFTER_3  -> after 3 conversions
   *  ADS1115_DISABLE_ALERT   -> disable comparator / alert pin (default) 
   */
  adc.setAlertPinMode(ADS1115_ASSERT_AFTER_1); // you can also choose ...AFTER_2 or 3 for this sketch

  /* Set the conversion rate in SPS (samples per second)
   * Options should be self-explaining: 
   * 
   *  ADS1115_8_SPS 
   *  ADS1115_16_SPS  
   *  ADS1115_32_SPS 
   *  ADS1115_64_SPS  
   *  ADS1115_128_SPS (default)
   *  ADS1115_250_SPS 
   *  ADS1115_475_SPS 
   *  ADS1115_860_SPS 
   */
  //adc.setConvRate(ADS1115_8_SPS); //uncomment if you want to change the default

  /* Set continous or single shot mode:
   * 
   *  ADS1115_CONTINOUS  ->  continous mode
   *  ADS1115_SINGLE     ->  single shot mode (default)
   */
  adc.setMeasureMode(ADS1115_CONTINOUS); //comment or change if you want to change single shot

   /* Choose maximum limit or maxium and minimum alert limit (window)in Volt - alert pin will 
   *  be active when measured values are beyond the maximum limit or outside the window 
   *  Upper limit first: setAlertLimit_V(MODE, maximum, minimum)
   *  In max limit mode the minimum value is the limit where the alert pin will be deactivated 
   *  again (if not latched!)  
   * 
   *  ADS1115_MAX_LIMIT
   *  ADS1115_WINDOW
   * 
   */
  adc.setAlertModeAndLimit_V(ADS1115_WINDOW, 3.0, 1.5); //uncomment if you want to change the default
  
  /* Enable or disable latch. If latch is enabled the alarm pin will be active until the
   * conversion register is read (getResult functions). If disabled the alarm pin will be
   * deactivated with next value within limits. 
   *  
   *  ADS1115_LATCH_DISABLED (default)
   *  ADS1115_LATCH_ENABLED
   */
  adc.setAlertLatch(ADS1115_LATCH_ENABLED); //uncomment if you want to change the default

  /* Sets the alert pin polarity if active:
   *  
   *  /* Enable or disable latch. If latch is enabled the alarm pin will be active until the
   * conversion register is read (getResult functions). If disabled the alarm pin will be
   * deactivated with next value within limits. 
   *  
   * ADS1115_ACT_LOW  ->  active low (default)   
   * ADS1115_ACT_HIGH ->  active high
   */
  //adc.setAlertPol(ADS1115_ACT_LOW); //uncomment if you want to change the default
 
  /* With this function the alert pin will be active, when a conversion is ready.
   * In order to deactivate, use the setAlertLimit_V function  
   */
  //adc.setAlertPinToConversionReady(); //uncomment if you want to change the default

  Serial.println("ADS1115 Example Sketch - uses the Alert Pin / Window Mode / Latch enabled");
  Serial.println();
  Serial.println("Waiting for Value out of Limit");
  attachInterrupt(digitalPinToInterrupt(interruptPin), outOfLimitAlert, FALLING);
  adc.startSingleMeasurement();
}

void loop() {
  float voltage = 0.0;
  if(outOfLimit){
    voltage = adc.getResult_V();
    Serial.print("Voltage [V]: ");
    Serial.println(voltage);  
    digitalWrite(ledPin,HIGH);
    delay(1000);
    digitalWrite(ledPin,LOW);
    outOfLimit = false;
    attachInterrupt(digitalPinToInterrupt(interruptPin), outOfLimitAlert, FALLING); 
    adc.unlatchAlertPin(); // unlatches the alert Pin (alternatively use getResult_V)
  } 
}

void outOfLimitAlert(){
  detachInterrupt(2);
  outOfLimit = true;
}