I want a delay to be triggered every time a DS3231 RTC interrupts. The RTC interrupt happens every 30 minutes which will turn on a motor. I want the motor on for 5 minutes. I need to figure out how to use a ESP32 timer to start when it sees the RTC interrupt and send its own interrupt trigger after 5 minutes is up so the code knows when to turn the motor off again. The RTC interrupts works great but I'm not understanding the timer operation for the 5 minute delay.

The code I enclosed is a failed test that used a switch as the trigger and a LED that lights for 100 seconds.  Why does this code flash the led every 200ms without even triggering with the input switch on i/o 35? What needs to to done to allow the above described functionality?

#include <Arduino.h>
#define LED_PIN 38      // Pin connected to the LED
#define INPUT_PIN 35    // Pin connected to the input
volatile uint8_t led_state = 0;

hw_timer_t * timer = NULL;

void IRAM_ATTR timer_isr() 
{
    led_state = !led_state; // Toggle the LED state
    digitalWrite(LED_PIN, !digitalRead(LED_PIN)); // Toggle the LED state
    Serial.println("Timer interrupt triggered!"); // Print a message to the serial monitor
    delay(200); 
}

void setup() 
{
  Serial.begin(115200);
  pinMode(LED_PIN, OUTPUT);
  pinMode(INPUT_PIN, INPUT); // Set the input pin as input
  uint8_t timer_id = 0;
  uint16_t prescaler = 8000; // Between 0 and 65535
  int threshold = 1000000; // 64 bits value (limited to int size of 32bits)

  timer = timerBegin(timer_id, prescaler, true);    //Timer #, prescaler, count up
  timerAttachInterrupt(timer, &timer_isr, true);    //Timer object, isr, rising edge trigger
  timerAlarmWrite(timer, threshold, false);         //Timer object, Value to reach /trigger at, No Auto reload
  //timerAlarmEnable(timer);
}

void loop() 
{
  if (digitalRead(INPUT_PIN) == LOW) // Check if the input pin is LOW
  {    
    //timerRestart(timer);
    timerAlarmEnable(timer);
  }
}

I want a delay to be triggered every time a DS3231 RTC interrupts. The RTC interrupt happens every 30 minutes which will turn on a motor. I want the motor on for 5 minutes. I need to figure out how to use a ESP32 timer to start when it sees the RTC interrupt and send its own interrupt trigger after 5 minutes is up so the code knows when to turn the motor off again. The RTC interrupts works great but I'm not understanding the timer operation for the 5 minute delay.

The code I enclosed is a failed test that used a switch as the trigger and a LED that lights for 100 seconds.  Why does this code flash the led every 200ms without even triggering with the input switch on i/o 35? What needs to to done to allow the above described functionality?

#include <Arduino.h>
#define LED_PIN 38      // Pin connected to the LED
#define INPUT_PIN 35    // Pin connected to the input
volatile uint8_t led_state = 0;

hw_timer_t * timer = NULL;

void IRAM_ATTR timer_isr() 
{
    led_state = !led_state; // Toggle the LED state
    digitalWrite(LED_PIN, !digitalRead(LED_PIN)); // Toggle the LED state
    Serial.println("Timer interrupt triggered!"); // Print a message to the serial monitor
    delay(200); 
}

void setup() 
{
  Serial.begin(115200);
  pinMode(LED_PIN, OUTPUT);
  pinMode(INPUT_PIN, INPUT); // Set the input pin as input
  uint8_t timer_id = 0;
  uint16_t prescaler = 8000; // Between 0 and 65535
  int threshold = 1000000; // 64 bits value (limited to int size of 32bits)

  timer = timerBegin(timer_id, prescaler, true);    //Timer #, prescaler, count up
  timerAttachInterrupt(timer, &timer_isr, true);    //Timer object, isr, rising edge trigger
  timerAlarmWrite(timer, threshold, false);         //Timer object, Value to reach /trigger at, No Auto reload
  //timerAlarmEnable(timer);
}

void loop() 
{
  if (digitalRead(INPUT_PIN) == LOW) // Check if the input pin is LOW
  {    
    //timerRestart(timer);
    timerAlarmEnable(timer);
  }
}
#include <Arduino.h>
#define LED_PIN 38      // Pin connected to the LED
#define INPUT_PIN 35    // Pin connected to the input
volatile uint8_t led_state = 0;


hw_timer_t * timer = NULL;


void IRAM_ATTR timer_isr() 
{
    led_state = !led_state; // Toggle the LED state
    digitalWrite(LED_PIN, !digitalRead(LED_PIN)); // Toggle the LED state
    Serial.println("Timer interrupt triggered!"); // Print a message to the serial monitor
    delay(200); 
}


void setup() 
{
  Serial.begin(115200);
  pinMode(LED_PIN, OUTPUT);
  pinMode(INPUT_PIN, INPUT); // Set the input pin as input
  uint8_t timer_id = 0;
  uint16_t prescaler = 8000; // Between 0 and 65535
  int threshold = 1000000; // 64 bits value (limited to int size of 32bits)


  timer = timerBegin(timer_id, prescaler, true);    //Timer #, prescaler, count up
  timerAttachInterrupt(timer, &timer_isr, true);    //Timer object, isr, rising edge trigger
  timerAlarmWrite(timer, threshold, false);         //Timer object, Value to reach /trigger at, No Auto reload
  //timerAlarmEnable(timer);
}


void loop() 
{
  if (digitalRead(INPUT_PIN) == LOW) // Check if the input pin is LOW
  {    
    //timerRestart(timer);
    timerAlarmEnable(timer);
  }
}