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Added method to set random local port #116

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Merged
merged 3 commits into from
Sep 3, 2020
Merged

Added method to set random local port #116

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a8bdae7
Added method to set random local port
Aug 31, 2020
9e4323b
Adding range choice for setRandomPort()
Aug 31, 2020
f567329
Changing long into unsigned int
Sep 3, 2020
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12 changes: 9 additions & 3 deletions NTPClient.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -73,7 +73,7 @@ void NTPClient::begin() {
this->begin(NTP_DEFAULT_LOCAL_PORT);
}

void NTPClient::begin(int port) {
void NTPClient::begin(long port) {
this->_port = port;

this->_udp->begin(this->_port);
Expand Down Expand Up @@ -120,7 +120,7 @@ bool NTPClient::forceUpdate() {
bool NTPClient::update() {
if ((millis() - this->_lastUpdate >= this->_updateInterval) // Update after _updateInterval
|| this->_lastUpdate == 0) { // Update if there was no update yet.
if (!this->_udpSetup) this->begin(); // setup the UDP client if needed
if (!this->_udpSetup || this->_port != NTP_DEFAULT_LOCAL_PORT) this->begin(this->_port); // setup the UDP client if needed
return this->forceUpdate();
}
return false; // return false if update does not occur
Expand Down Expand Up @@ -181,7 +181,8 @@ void NTPClient::sendNTPPacket() {
// set all bytes in the buffer to 0
memset(this->_packetBuffer, 0, NTP_PACKET_SIZE);
// Initialize values needed to form NTP request
// (see URL above for details on the packets)
// (see URL above for details on the packets) Serial.println(this->_port);

this->_packetBuffer[0] = 0b11100011; // LI, Version, Mode
this->_packetBuffer[1] = 0; // Stratum, or type of clock
this->_packetBuffer[2] = 6; // Polling Interval
Expand All @@ -202,3 +203,8 @@ void NTPClient::sendNTPPacket() {
this->_udp->write(this->_packetBuffer, NTP_PACKET_SIZE);
this->_udp->endPacket();
}

void NTPClient::setRandomPort(long minValue, long maxValue) {
randomSeed(analogRead(0));
this->_port = random(minValue, maxValue);
}
9 changes: 7 additions & 2 deletions NTPClient.h
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Expand Up @@ -15,7 +15,7 @@ class NTPClient {

const char* _poolServerName = "pool.ntp.org"; // Default time server
IPAddress _poolServerIP;
int _port = NTP_DEFAULT_LOCAL_PORT;
long _port = NTP_DEFAULT_LOCAL_PORT;
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Hi @luigigubello 👋 ☕ Is there any special reason why you change this data type from int to long? Certainly int is capable of holding values up 2^16-1 even on AVR 😉

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Certainly int is capable of holding values up 2^16-1 even on AVR

Reading the documentation I have understood it's not, but your suggestion to use unsigned int is a good idea. So, yes, I have chosen long instead int to be sure to maintain the AVR compatibility. It seems unsigned int is the best choice 🙂

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I've checked again - so yes, int 2 byte on AVR which covers from -2^15 to 2^15-1. unsigned int covers 0 to 2^16-1 which is enough.

long _timeOffset = 0;

unsigned long _updateInterval = 60000; // In ms
Expand Down Expand Up @@ -44,6 +44,11 @@ class NTPClient {
*/
void setPoolServerName(const char* poolServerName);

/**
* Set random local port
*/
void setRandomPort(long minValue, long maxValue);
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Same here ... I think int or even better unsigned int (as it excludes negative values) would do the job just nicely here.

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I think you are right


/**
* Starts the underlying UDP client with the default local port
*/
Expand All @@ -52,7 +57,7 @@ class NTPClient {
/**
* Starts the underlying UDP client with the specified local port
*/
void begin(int port);
void begin(long port);

/**
* This should be called in the main loop of your application. By default an update from the NTP Server is only
Expand Down