ESP32 Lightning Detector

// ESP32 Lightning Detector - Intermediate (NTP log + Telegram + storm trend)
#include <Wire.h>
#include <Adafruit_SSD1306.h>
#include <SPI.h>
#include <SparkFun_AS3935.h>
#include <WiFi.h>
#include <WiFiClientSecure.h>
#include <time.h>

#define AS3935_CS 5
#define AS3935_IRQ 4

SparkFun_AS3935 lightning(AS3935_CS);
Adafruit_SSD1306 oled(128,64,&Wire,-1);
const char* SSID="YourSSID", *PASS="YourPass";
const char* BOT_TOKEN="YOUR_BOT_TOKEN";
const char* CHAT_ID="YOUR_CHAT_ID";

volatile bool strike=false;
void IRAM_ATTR onStrike(){ strike=true; }

struct StrikeLog { time_t ts; int dist; };
StrikeLog history[5]; int histIdx=0;

void sendTelegram(const String &msg){
  WiFiClientSecure c; c.setInsecure();
  if(!c.connect("api.telegram.org",443)) return;
  String body="chat_id="+String(CHAT_ID)+"&text="+msg;
  c.printf("POST /bot%s/sendMessage HTTP/1.1rnHost: api.telegram.orgrn"
    "Content-Type: application/x-www-form-urlencodedrnContent-Length: %drnrn%s",
    BOT_TOKEN,(int)body.length(),body.c_str());
  delay(1000); c.stop();
}

void updateOLED(){
  oled.clearDisplay(); oled.setCursor(0,0); oled.setTextSize(1);
  oled.println("Recent strikes (km):");
  for(int i=0;i<5;i++){
    int idx=(histIdx-1-i+5)%5;
    if(history[idx].ts) oled.printf("%d km agon",history[idx].dist);
  }
  oled.display();
}

void setup(){
  Serial.begin(115200);
  Wire.begin(21,22);
  oled.begin(SSD1306_SWITCHCAPVCC,0x3C); oled.setTextColor(WHITE);
  SPI.begin();
  pinMode(AS3935_IRQ,INPUT);
  attachInterrupt(digitalPinToInterrupt(AS3935_IRQ),onStrike,RISING);
  lightning.beginSPI(AS3935_CS,2000000);
  lightning.setIndoorOutdoor(INDOOR);
  lightning.maskDisturber(true);
  WiFi.begin(SSID,PASS); while(WiFi.status()!=WL_CONNECTED) delay(500);
  configTime(0,0,"pool.ntp.org");
  Serial.printf("Lightning detector: %sn",WiFi.localIP().toString().c_str());
}

void loop(){
  if(!strike) return;
  strike=false; delay(5);
  if(lightning.readInterruptReg()!=LIGHTNING_INT) return;
  int dist=lightning.distanceToStorm();
  time_t now=time(nullptr);
  history[histIdx%5]={now,dist}; histIdx++;
  // Check trend: is storm approaching?
  bool approaching=false;
  if(histIdx>=2){
    int prev=history[(histIdx-2+5)%5].dist;
    int curr=history[(histIdx-1+5)%5].dist;
    approaching=(curr<prev);
  }
  String msg="LIGHTNING! ~"+String(dist)+"km "+(approaching?"APPROACHING":"retreating");
  struct tm ti; localtime_r(&now,&ti);
  char ts[20]; strftime(ts,sizeof(ts),"%H:%M:%S",&ti);
  msg+=" ("+String(ts)+")";
  Serial.println(msg);
  sendTelegram(msg);
  updateOLED();
}