Example script to log flashing light to influxdb via UDP. See https://blog.haschek.at/smartmeter for more info

smartmeter.ino

#include <ESP8266WiFi.h>
#include <WiFiUdp.h>

WiFiUDP Udp;
const char* ssid = "yourwifiSSID";
const char* password = "yourwifipassword";
const int threshold = 400;        //this is the threshold how high the value has to be to be registered as a flash.
                                  //400 works great for me since flashes are usually ~600

IPAddress remoteIP(192,168,1,117); // the IP address of your Influxdb server
unsigned int remotePort = 8093;   // the UDP (!!) port of your Influxdb you set up
                                  // how to do that? https://docs.influxdata.com/influxdb/v1.6/supported_protocols/udp/#config-examples

int lasthigh = 0;
int lastval = 0;
unsigned long counter = 0;

void setup() {
  Serial.begin(115200);
  WifiConnect();
}

void loop() {
   WifiConnect();
  int val = analogRead(A0);
  if(lastval < threshold && val > threshold)
  {
      char  replyPacket[] = "strom,loc=zaehler value=1";
      Udp.beginPacket(remoteIP, remotePort)
      Serial.println(Udp.write(replyPacket));
      Serial.println(Udp.endPacket());
  }
  
  lastval = val;
  delay(10);
}


void WifiConnect()
{
  if(WiFi.status() == WL_CONNECTED)
  {
    return;
  }

  int count = 0;

  
  WiFi.mode(WIFI_AP_STA);
  WiFi.begin(ssid, password);

  Serial.println("Reconnecting to wifi");
  
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    count++;
    if(count>10){
      Serial.println("tried 10 times to connect.. restarting");
      WiFi.disconnect();
      ESP.restart();
      return;
    }
  }
  Serial.println("");
  Serial.println("WiFi connected");
  Serial.println(WiFi.localIP());

}