Count esp8266 reboots

reboot_counter.cpp

#include "Arduino.h"

#define RTC_MARKER 0x1234

unsigned int marker = 0;
unsigned int reboots = 0;

void setup() {
  // initialize LED digital pin as an output.
  pinMode(LED_BUILTIN, OUTPUT);
  
  Serial.begin(74880);

  ESP.rtcUserMemoryRead(0, &marker, sizeof(marker));
  if (marker != RTC_MARKER) {
    // first reboot
    marker = RTC_MARKER;
    reboots = 0;
    ESP.rtcUserMemoryWrite(0, &marker,sizeof(marker));
  } else {
    // read count of reboots
    ESP.rtcUserMemoryRead(sizeof(marker), &reboots, sizeof(reboots));
  }
  reboots++;
  ESP.rtcUserMemoryWrite(sizeof(marker), &reboots, sizeof(reboots));

  Serial.printf("Number of reboots : %d\r\n", reboots);

  if (reboots == 10) {
    Serial.println("Welcome, 10th visior =)");
  }
  delay(2000);
  
  
  // turn the LED on (HIGH is the voltage level)
  digitalWrite(LED_BUILTIN, HIGH);
  // wait for a second
  delay(1000);
  // turn the LED off by making the voltage LOW
  digitalWrite(LED_BUILTIN, LOW);
  // wait for a second
  delay(1000);
  

  ESP.deepSleep(RF_DISABLED);
}

void loop() {}