/*
  Deep Sleep with Touch Wake Up
  This code displays how to use deep sleep with a touch as a wake up source and how to store data in RTC memory to use it over reboots
  ESP32 can have multiple touch pads enabled as wakeup source
  ESP32-S2 and ESP32-S3 supports only 1 touch pad as wakeup source enabled
  This code is under Public Domain License. Author: Pranav Cherukupalli <[email protected]>
*/

#if CONFIG_IDF_TARGET_ESP32
  #define THRESHOLD   40      /* Greater the value, more the sensitivity */
#else //ESP32-S2 and ESP32-S3 + default for other chips (to be adjusted) */
  #define THRESHOLD   5000   /* Lower the value, more the sensitivity */
#endif

RTC_DATA_ATTR int bootCount = 0;
touch_pad_t touchPin;
/*
Method to print the reason by which ESP32
has been awaken from sleep
*/
void print_wakeup_reason(){
  esp_sleep_wakeup_cause_t wakeup_reason;

  wakeup_reason = esp_sleep_get_wakeup_cause();

  switch(wakeup_reason)
  {
    case ESP_SLEEP_WAKEUP_EXT0 : Serial.println("Wakeup caused by external signal using RTC_IO"); break;
    case ESP_SLEEP_WAKEUP_EXT1 : Serial.println("Wakeup caused by external signal using RTC_CNTL"); break;
    case ESP_SLEEP_WAKEUP_TIMER : Serial.println("Wakeup caused by timer"); break;
    case ESP_SLEEP_WAKEUP_TOUCHPAD : Serial.println("Wakeup caused by touchpad"); break;
    case ESP_SLEEP_WAKEUP_ULP : Serial.println("Wakeup caused by ULP program"); break;
    default : Serial.printf("Wakeup was not caused by deep sleep: %d\n",wakeup_reason); break;
  }
}

/*
Method to print the touchpad by which ESP32
has been awaken from sleep
*/
void print_wakeup_touchpad(){
  touchPin = esp_sleep_get_touchpad_wakeup_status();

  #if CONFIG_IDF_TARGET_ESP32
    switch(touchPin)
    {
      case 0  : Serial.println("Touch detected on GPIO 4"); break;
      case 1  : Serial.println("Touch detected on GPIO 0"); break;
      case 2  : Serial.println("Touch detected on GPIO 2"); break;
      case 3  : Serial.println("Touch detected on GPIO 15"); break;
      case 4  : Serial.println("Touch detected on GPIO 13"); break;
      case 5  : Serial.println("Touch detected on GPIO 12"); break;
      case 6  : Serial.println("Touch detected on GPIO 14"); break;
      case 7  : Serial.println("Touch detected on GPIO 27"); break;
      case 8  : Serial.println("Touch detected on GPIO 33"); break;
      case 9  : Serial.println("Touch detected on GPIO 32"); break;
      default : Serial.println("Wakeup not by touchpad"); break;
    }
  #else
    if(touchPin < TOUCH_PAD_MAX)
    {
      Serial.printf("Touch detected on GPIO %d\n", touchPin); 
    }
    else
    {
      Serial.println("Wakeup not by touchpad");
    }
  #endif
}

void setup(){
  Serial.begin(115200);
  delay(1000); //Take some time to open up the Serial Monitor

  //Increment boot number and print it every reboot
  ++bootCount;
  Serial.println("Boot number: " + String(bootCount));

  //Print the wakeup reason for ESP32 and touchpad too
  print_wakeup_reason();
  print_wakeup_touchpad();

  #if CONFIG_IDF_TARGET_ESP32 
  //Setup sleep wakeup on Touch Pad 3 + 7 (GPIO15 + GPIO 27) 
  touchSleepWakeUpEnable(T3,THRESHOLD);
  touchSleepWakeUpEnable(T7,THRESHOLD);
  
  #else //ESP32-S2 + ESP32-S3
  //Setup sleep wakeup on Touch Pad 3 (GPIO3) 
  touchSleepWakeUpEnable(T3,THRESHOLD);

  #endif

  //Go to sleep now
  Serial.println("Going to sleep now");
  esp_deep_sleep_start();
  Serial.println("This will never be printed");
}

void loop(){
  //This will never be reached
}

//also we use interrupt in this so that when the esp is wakeup then the callback function is call 
//touchAttachInterrupt(T3, callback, Threshold);