/*  WiFiUDPCLient_WA
 *  Zeitmessung und senden dern Daten über UDP sowie gleichzeitige
 *  Anzeige in der Seriellen Schnittstelle
 */
#include <WiFi.h>
#include <WiFiUdp.h>

// WiFi network name and password:
const char * networkName = "JuergenWalter";                           //"HIT-FRITZBOX-7490" - TP-LINK_Pocket_3020_304938
const char * networkPswd = "44873763559236747268";                    //"63601430989011937932"   - 42820895

//IP address to send UDP data to: 
// either use the ip address of the server or 
// a network broadcast address
const char * udpAddress = "192.168.188.21";              //Adresse auf UDP-Empfaenger einstellen
const int udpPort = 3333;                                //Port auf UDP-Empfaenger (Handy) einstellen App

//Are we currently connected?
boolean connected = false;

//The udp library class
WiFiUDP udp;

//Variable
unsigned long Zeit;
unsigned long Start;
unsigned long Ende;
int s,ms;
unsigned MessungNr=0;


void setup(){
  // Initilize hardware serial:
  Serial.begin(115200);
  
  //Connect to the WiFi network
  connectToWiFi(networkName, networkPswd);
}

void loop(){
  //only send data when connected
  if(connected){
    //Send a packet
    
    //Warten bis Messung gestartet
    while (digitalRead(0) == HIGH)
 {
    //warten 
 }
  
  Start =  millis();
  MessungNr = MessungNr+1;
  Serial.print("Gestartet: Messung Nr.: ");
  Serial.print(MessungNr);

    udp.beginPacket(udpAddress,udpPort);
    udp.printf("Gestartet Messung Nr: %u", MessungNr);
    udp.endPacket();
    
  delay(2000);
  while (digitalRead(0) == HIGH)
 {
  //warten
 }
  Serial.print("  Ergebnis: ");
  Ende = millis();
  Zeit = (Ende - Start);

  //Umrechnung fuer Anzeige
  s=int(Zeit/1000);
  ms=Zeit % 1000;
  //prints Zeit since program started
  Serial.print(s);
  Serial.print(".");
  Serial.print(ms);
  Serial.print("s");
  Serial.println(); 
  // wait a second 
    
    udp.beginPacket(udpAddress,udpPort);
    udp.printf("Zeit: %u.%u s", s,ms);
    udp.endPacket();
  }
  //Wait for 100omsecond
  delay(1000);
}

void connectToWiFi(const char * ssid, const char * pwd){
  Serial.println("Connecting to WiFi network: " + String(ssid));

  // delete old config
  WiFi.disconnect(true);
  //register event handler
  WiFi.onEvent(WiFiEvent);
  
  //Initiate connection
  WiFi.begin(ssid, pwd);

  Serial.println("Waiting for WIFI connection...");
}

//wifi event handler
void WiFiEvent(WiFiEvent_t event){
    switch(event) {
      case SYSTEM_EVENT_STA_GOT_IP:
          //When connected set 
          Serial.print("WiFi connected! IP address: ");
          Serial.println(WiFi.localIP());  
          //initializes the UDP state
          //This initializes the transfer buffer
          udp.begin(WiFi.localIP(),udpPort);
          connected = true;
          break;
      case SYSTEM_EVENT_STA_DISCONNECTED:
          Serial.println("WiFi lost connection");
          connected = false;
          break;
    }
}