Arduino Mega Server und Echtzeituhr

/*
Modul Virtual RTC
part of Arduino Mega Server project
*/

// Virtual RTC

IPAddress timeServer(192, 168, 2, 8);
unsigned int localPort = 8888; // local port to listen for UDP packets
EthernetUDP Udp;

const int timeZone = 4;
time_t prevDisplay = 0; // when the digital clock was displayed

void rtcInit() {
Udp.begin(localPort);
Serialprint(«Waiting for NTP sync… \n»);
setSyncProvider(getNtpTime);
modulRtc = 1;
}

void rtcWorks() {
if (timeStatus() != timeNotSet) {
if (now() != prevDisplay) { // update the display only if time has changed
setLifer();
prevDisplay = now();
//digitalClockDisplay();
}
}
}

void printDigits(int digits) {
if(digits < 10) {
Serial.print('0');
}
Serial.print(digits);
}

void serialRTC() {
Serial.print(year());
Serial.print("-");
printDigits(month());
Serial.print("-");
printDigits(day());
Serial.print(" ");
printDigits(hour());
Serial.print(":");
printDigits(minute());
Serial.print(":");
printDigits(second());
}

void timeStamp() {
serialRTC();
Serial.print(" ");
}

void printRTC(){
serialRTC();
Serial.println();
}

// NTP code

const int NTP_PACKET_SIZE = 48; // NTP time is in the first 48 bytes of message
byte packetBuffer[NTP_PACKET_SIZE]; //buffer to hold incoming & outgoing packets

#ifdef RTC_FEATURE

time_t getNtpTime() {
while (Udp.parsePacket() > 0); // discard any previously received packets
Serialprint(«Transmit NTP request\n»);
sendNTPpacket(timeServer);
uint32_t beginWait = millis();
while (millis() — beginWait < 1500) {
int size = Udp.parsePacket();
if (size >= NTP_PACKET_SIZE) {
Serialprint(«Receive NTP response\n»);
Udp.read(packetBuffer, NTP_PACKET_SIZE); // read packet into the buffer
unsigned long secsSince1900;
// convert four bytes starting at location 40 to a long integer
secsSince1900 = (unsigned long)packetBuffer[40] << 24;
secsSince1900 |= (unsigned long)packetBuffer[41] << 16;
secsSince1900 |= (unsigned long)packetBuffer[42] << 8;
secsSince1900 |= (unsigned long)packetBuffer[43];
return secsSince1900 — 2208988800UL + timeZone * SECS_PER_HOUR;
}
}
Serialprint(«No NTP response\n»);
return 0; // return 0 if unable to get the time
}

// send an NTP request to the time server at the given address
void sendNTPpacket(IPAddress &address) {
// set all bytes in the buffer to 0
memset(packetBuffer, 0, NTP_PACKET_SIZE);
// Initialize values needed to form NTP request
// (see URL above for details on the packets)
packetBuffer[0] = 0b11100011; // LI, Version, Mode
packetBuffer[1] = 0; // Stratum, or type of clock
packetBuffer[2] = 6; // Polling Interval
packetBuffer[3] = 0xEC; // Peer Clock Precision
// 8 bytes of zero for Root Delay & Root Dispersion
packetBuffer[12] = 49;
packetBuffer[13] = 0x4E;
packetBuffer[14] = 49;
packetBuffer[15] = 52;
// all NTP fields have been given values, now
// you can send a packet requesting a timestamp:
Udp.beginPacket(address, 123); //NTP requests are to port 123
Udp.write(packetBuffer, NTP_PACKET_SIZE);
Udp.endPacket();
}

#endif

// Duration

void showDuration(time_t duration) {
// prints the duration in days, hours, minutes and seconds
Serialprint(" (duration ");
if(duration >= SECS_PER_DAY){
Serial.print(duration / SECS_PER_DAY);
Serialprint(" day ");
duration = duration % SECS_PER_DAY;
}
if(duration >= SECS_PER_HOUR){
Serial.print(duration / SECS_PER_HOUR);
Serialprint(" hour ");
duration = duration % SECS_PER_HOUR;
}
if(duration >= SECS_PER_MIN){
Serial.print(duration / SECS_PER_MIN);
Serialprint(" min ");
duration = duration % SECS_PER_MIN;
}
Serial.print(duration);
Serialprint(" sec) \n");
}

void checkEvent(time_t* prevEvent) {
time_t duration = 0;
time_t timeNow = now();

if (*prevEvent > 0) {
duration = timeNow — *prevEvent;
}
if (duration > 0) {
showDuration(duration);
}
*prevEvent = timeNow;
}