Super simple 1000 pulses generator.

1000_pulses.ino

/*
  1000 pulses generator (100ms width/5 Hz)
  
  Send pulseCount to MOSFET transitor connect to D2 pin.
  Push FLASH button (link to D3) to start generator.
  Push RST button to stop generator and clear counter.
  
  Test with ESP-12 on nodemcu.
  
  This example code is in the public domain.

*/

// const
#define PIN_PULSE D2
#define PIN_FLASH_BUTTON D3
#define PULSE_NB 1000
#define PULSE_WIDTH_MS 100

// vars
bool do_pulse = false;
uint32_t pulseCount = PULSE_NB;


void setup() {
  // initialize digital pin LED_BUILTIN as an output.
  pinMode(PIN_PULSE, OUTPUT);
  digitalWrite(PIN_PULSE, LOW);
  // flash button
  pinMode(PIN_FLASH_BUTTON, INPUT);
}


void loop() {
  // wait button press
  if(digitalRead(PIN_FLASH_BUTTON) == LOW)
    do_pulse = true;
  // pulse generator
  if(do_pulse and pulseCount > 0) {
    digitalWrite(PIN_PULSE, HIGH);
    delay(PULSE_WIDTH_MS);           
    digitalWrite(PIN_PULSE, LOW);
    delay(PULSE_WIDTH_MS);
    pulseCount--;
  }
  // reset value for next loop
  if(pulseCount == 0) {
    pulseCount = PULSE_NB;
    do_pulse = false;
  }
}