v1.7

NTP.cpp

@@ -32,18 +32,25 @@ NTP::~NTP() {
 
 void NTP::begin(const char* server) {
 	this->server = server;
-	udp->begin(NTP_PORT);
-	ntpUpdate();
-	if (dstZone) {
-		timezoneOffset = dstEnd.tzOffset * SECS_PER_MINUTES;
-		dstOffset = (dstStart.tzOffset - dstEnd.tzOffset) * SECS_PER_MINUTES;
-		currentTime();
-		beginDST();
-		} 
+	init(); 
 	}
 
 void NTP::begin(IPAddress serverIP) {
 	this->serverIP = serverIP;
+	init();
+	}
+
+void NTP::init() {
+	memset(ntpRequest, 0, NTP_PACKET_SIZE);
+  ntpRequest[0] = 0b11100011; // LI, Version, Mode
+  ntpRequest[1] = 0;          // Stratum, or type of clock
+  ntpRequest[2] = 6;          // Polling Interval
+  ntpRequest[3] = 0xEC;       // Peer Clock Precision
+  // 8 bytes of zero for Root Delay & Root Dispersion
+  ntpRequest[12]  = 49;
+  ntpRequest[13]  = 0x4E;
+  ntpRequest[14]  = 49;
+  ntpRequest[15]  = 52;
 	udp->begin(NTP_PORT);
 	ntpUpdate();
 	if (dstZone) {
@@ -66,7 +73,6 @@ bool NTP::update() {
 	}
 
 bool NTP::ntpUpdate() {
-	udp->flush();
 	if (server == nullptr) udp->beginPacket(serverIP, NTP_PORT);
 	else udp->beginPacket(server, NTP_PORT);
 	udp->write(ntpRequest, NTP_PACKET_SIZE);
@@ -81,8 +87,23 @@ bool NTP::ntpUpdate() {
 		} while (size != 48);
 	lastUpdate = millis() - (10 * (timeout + 1));
 	udp->read(ntpQuery, NTP_PACKET_SIZE);
-	uint32_t ntpTime = ntpQuery[40] << 24 | ntpQuery[41] << 16 | ntpQuery[42] << 8 | ntpQuery[43];
-	utcTime = ntpTime - SEVENTYYEARS;
+	#ifdef __AVR__
+ 		unsigned long highWord = word(ntpQuery[40], ntpQuery[41]);
+		unsigned long lowWord = word(ntpQuery[42], ntpQuery[43]);
+		timestamp = highWord << 16 | lowWord;
+		if (timestamp != 0) {
+ 			ntpTime = timestamp;
+ 			utcTime = ntpTime - NTP_OFFSET;
+			}
+		else return false;
+ 	#else
+ 		timestamp = ntpQuery[40] << 24 | ntpQuery[41] << 16 | ntpQuery[42] << 8 | ntpQuery[43];
+		if (timestamp != 0) {
+ 			ntpTime = timestamp;
+ 			utcTime = ntpTime - SEVENTYYEARS;
+			}
+		else return false;
+ 	#endif
 	return true;
 	}
 
@@ -156,7 +177,7 @@ time_t NTP::epoch() {
 	}
 
 void NTP::currentTime() {
-	utcCurrent = diffTime + utcTime + ((millis() - lastUpdate) / 1000); 
+	utcCurrent = utcTime + ((millis() - lastUpdate) / 1000); 
 	if (dstZone) {
 		if (summerTime()) {
 			local = utcCurrent + dstOffset + timezoneOffset;
@@ -256,4 +277,12 @@ bool NTP::summerTime() {
 	else {
 		return false;
 		}
-	}
+	}
+
+uint32_t NTP::ntp() {
+	return ntpTime;
+	}
+
+uint32_t NTP::utc() {
+	return utcTime;
+	}

NTP.h

@@ -28,6 +28,15 @@
 #include <Udp.h>
 
 #define SEVENTYYEARS 2208988800UL
+#define UNIXOFFSET 946684800UL
+
+#ifdef __AVR__
+  //#define POSIX_OFFSET NTP_OFFSET - SEVENTYYEARS// - UNIX_OFFSET// + 30 years
+  #define POSIX_OFFSET UNIXOFFSET
+#else
+  #define POSIX_OFFSET -SEVENTYYEARS
+#endif
+
 #define NTP_PACKET_SIZE 48
 #define NTP_PORT 123
 #define SECS_PER_MINUTES 60
@@ -222,11 +231,25 @@ class NTP {
      */
     const char* formattedTime(const char *format);
 
+    /**
+     * @brief returns NTP timestamp
+     * 
+     * @return uint32_t 
+     */
+    uint32_t ntp();
+
+    /**
+     * @brief returns UNIX timestamp
+     * 
+     * @return uint32_t 
+     */
+    uint32_t utc();
+
   private:
     UDP *udp;
     const char* server = nullptr;
     IPAddress serverIP;
-    const uint8_t ntpRequest[NTP_PACKET_SIZE] = {0xE3, 0x00, 0x06, 0xEC};
+    uint8_t ntpRequest[NTP_PACKET_SIZE]; // = {0xE3, 0x00, 0x06, 0xEC};
     uint8_t ntpQuery[NTP_PACKET_SIZE];
     time_t utcCurrent = 0;
     time_t local = 0;
@@ -238,8 +261,9 @@ class NTP {
     int32_t timezoneOffset;
     int16_t dstOffset = 0;
     bool dstZone = true;
-    uint32_t utcTime = 0;
-    int32_t diffTime;    
+    uint32_t timestamp;
+    uint32_t ntpTime = 0;
+    uint32_t utcTime = 0;   
     time_t utcSTD, utcDST;
     time_t dstTime, stdTime;
     uint16_t yearDST;
@@ -252,13 +276,13 @@ class NTP {
 	    int8_t hour;   // 0 - 23
 	    int tzOffset;   // offset from UTC in minutes
       } dstStart, dstEnd;
+    void init();
     bool ntpUpdate();
-    uint32_t localTime();
+    time_t localTime();
     void currentTime();
     void beginDST();
     time_t calcDateDST(struct ruleDST rule, int year);
     bool summerTime();
-
 };
 
 #endif

README.md

@@ -3,7 +3,10 @@ The **NTP** library allows you to receive time information from the Internet. It
 different timezones and daylight saving time (DST).
 This NTP library uses the functions of the time.h standard library.<br>
 
-The library doesn't work with AVR boards like UNO WiFi Rev2 because it seems there is a bug in "time.h" of the AVR C library.
+## Changes for 1.7
+
+- support for AVR
+- optimizations 
 
 ## Changes for 1.6
 
@@ -92,7 +95,7 @@ void stop();
 ```
 Stop the underlaying UDP client
 
-Example
+Example, this must done in ```setup()```
 ```cpp
 ntp.stop();
 ```
@@ -307,6 +310,21 @@ Format symbols:
 | p | writes localized a.m. or p.m. (locale dependent)
 ```
 
+## Return utc()
+
+ ```cpp
+ uint32_t utc();
+ ```
+
+ Return the timestamp received from the ntp server in Unix timestamp format
+
+ ## Return ntp()
+
+ ```cpp
+ uint32_t ntp();
+ ```
+
+ Return the timestamp received from the ntp server in the NTP timestamp format
 
 
 

keywords.txt

@@ -26,3 +26,5 @@ hours	KEYWORD2
 minutes	KEYWORD2
 seconds	KEYWORD2
 formattedTime	KEYWORD2
+utc	KEYWORD2
+ntp	KEYWORD2

library.json

@@ -1,13 +1,13 @@
 {
   "name": "NTP",
   "keywords": "ntp, client, time, timezone",
-  "description": "a NTP client with timezone support",
+  "description": "A NTP client with timezone support",
   "repository":
   {
     "type": "git",
     "url": "https://github.com/sstaub/NTP.git"
   },
-  "version": "1.6",
+  "version": "1.7",
   "frameworks": "arduino",
   "platforms": "*"
 }

library.properties

@@ -1,5 +1,5 @@
 name=NTP
-version=1.6
+version=1.7
 author=Stefan Staub
 maintainer=Stefan Staub <[email protected]>
 sentence=NTP library