'sendNTPpacket' was not declared in this scope [SOLVED]

Hello, I am using the UdpNtpClient example code with a change. Instead of the WIZNET 5100 chip I am using the ethernet shield with the WIZNET 5500 chip. Here is the code:

#include <SPI.h>         
#include <Ethernet.h>
#include <EthernetUdp.h>

// Enter a MAC address for your controller below.
// Newer Ethernet shields have a MAC address printed on a sticker on the shield
#if defined(WIZ550io_WITH_MACADDRESS) // Use assigned MAC address of WIZ550io
;
#else
byte mac[] = {0x90, 0xA2, 0xDA, 0x10, 0x21, 0xCB};
#endif  

unsigned int localPort = 8888;      // local port to listen for UDP packets

char timeServer[] = "time.nist.gov"; //NTP server

const int NTP_PACKET_SIZE = 48; // NTP time stamp is in the first 48 bytes of the message

byte packetBuffer[NTP_PACKET_SIZE]; //buffer to hold incoming and outgoing packets 

// A UDP instance to let us send and receive packets over UDP
EthernetUDP Udp;

void setup() 
{
 // Open serial communications and wait for port to open:
  Serial.begin(9600);
   while (!Serial) {
    ; // wait for serial port to connect. Needed for Leonardo only
  }


  // start Ethernet and UDP
#if defined(WIZ550io_WITH_MACADDRESS)
  if (Ethernet.begin() == 0) {
#else
  if (Ethernet.begin(mac) == 0) {
#endif  
    Serial.println("Failed to configure Ethernet using DHCP");
    // no point in carrying on, so do nothing forevermore:
    for(;;)
      ;
  }
  Udp.begin(localPort);
}

void loop()
{
sendNTPpacket(timeServer); // send an NTP packet to a time server

    // wait to see if a reply is available
  delay(1000);  
  if ( Udp.parsePacket() ) {  
    // We've received a packet, read the data from it
    Udp.read(packetBuffer,NTP_PACKET_SIZE);  // read the packet into the buffer

    //the timestamp starts at byte 40 of the received packet and is four bytes,
    // or two words, long. First, esxtract the two words:

    unsigned long highWord = word(packetBuffer[40], packetBuffer[41]);
    unsigned long lowWord = word(packetBuffer[42], packetBuffer[43]);  
    // combine the four bytes (two words) into a long integer
    // this is NTP time (seconds since Jan 1 1900):
    unsigned long secsSince1900 = highWord << 16 | lowWord;  
    Serial.print("Seconds since Jan 1 1900 = " );
    Serial.println(secsSince1900);               

    // now convert NTP time into everyday time:
    Serial.print("Unix time = ");
    // Unix time starts on Jan 1 1970. In seconds, that's 2208988800:
    const unsigned long seventyYears = 2208988800UL;     
    // subtract seventy years:
    unsigned long epoch = secsSince1900 - seventyYears;  
    // print Unix time:
    Serial.println(epoch);                               


    // print the hour, minute and second:
    Serial.print("The UTC time is ");       // UTC is the time at Greenwich Meridian (GMT)
    Serial.print((epoch  % 86400L) / 3600); // print the hour (86400 equals secs per day)
    Serial.print(':');  
    if ( ((epoch % 3600) / 60) < 10 ) {
      // In the first 10 minutes of each hour, we'll want a leading '0'
      Serial.print('0');
    }
    Serial.print((epoch  % 3600) / 60); // print the minute (3600 equals secs per minute)
    Serial.print(':'); 
    if ( (epoch % 60) < 10 ) {
      // In the first 10 seconds of each minute, we'll want a leading '0'
      Serial.print('0');
    }
    Serial.println(epoch %60); // print the second
  }
  // wait ten seconds before asking for the time again
  delay(10000); 
  Ethernet.maintain();
}

// send an NTP request to the time server at the given address 
unsigned long sendNTPpacket(char* 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(); 
}

When I run this code I get the error: 'sendNTPpacket' was not declared in this scope with the line:
Udp.read(packetBuffer,NTP_PACKET_SIZE); highlighted.

The entire error code is:

UdpNtpClient.ino: In function 'void loop()':
UdpNtpClient.ino:82:25: error: 'sendNTPpacket' was not declared in this scope
'sendNTPpacket' was not declared in this scope

I don't know what's going on and I don't see why there is an issue with called the sendNTPpacket if it is declared as its own function near the end of the code. I also don't understand why the Udp.read line is highlighted when the error comes up. Any help with this would be cgreatly appreciated. Thank you.

If you used Tools + Auto Format, you'd see immediately what the problem is.

That error message is a red herring. Take out the following and it should compile.

  // start Ethernet and UDP
#if defined(WIZ550io_WITH_MACADDRESS)
  if (Ethernet.begin() == 0) {
#else
  if (Ethernet.begin(mac) == 0) {
#endif 
    Serial.println("Failed to configure Ethernet using DHCP");
    // no point in carrying on, so do nothing forevermore:
    for(;;)
      ;
  }

I used the auto format of the IDE, which gave an error of too many left curly braces with the above code left in and no error with it removed.

You may want to redefine sendNTPpacket() as returning void.

Hello, thank you all for your help. Blue Eyes: I took out that section of the code and redefined sendNTPpacket as returning void. I also tried to see if removing the address, after char* in the declaration of sendNTPpacket did anything and I still got the error that sendNTPpacket was not delcared in this scope. Do you have any other suggestions?

Do you have any other suggestions?

You changed the code.
You didn't post the changed code.
So, yes, I have a suggestion. But, I'll refrain from making it.

Sorry about that here is the code:

#include <SPI.h>
#include <Ethernet.h>
#include <EthernetUdp.h>

// Enter a MAC address for your controller below.
// Newer Ethernet shields have a MAC address printed on a sticker on the shield
#if defined(WIZ550io_WITH_MACADDRESS) // Use assigned MAC address of WIZ550io
;
#else
byte mac[] = {0x90, 0xA2, 0xDA, 0x10, 0x21, 0xCB};
#endif

unsigned int localPort = 8888;      // local port to listen for UDP packets

char timeServer[] = "time.nist.gov"; //NTP server

const int NTP_PACKET_SIZE = 48; // NTP time stamp is in the first 48 bytes of the message

byte packetBuffer[NTP_PACKET_SIZE]; //buffer to hold incoming and outgoing packets

// A UDP instance to let us send and receive packets over UDP
EthernetUDP Udp;

void setup()
{
  // Open serial communications and wait for port to open:
  Serial.begin(9600);
  Udp.begin(localPort);
}








void loop()
{
 char* sendNTPpacket(timeServer); // send an NTP packet to a time server
  // wait to see if a reply is available
  delay(1000);
  if ( Udp.parsePacket() ) {
    // We've received a packet, read the data from it

    Udp.read(packetBuffer, NTP_PACKET_SIZE); // read the packet into the buffer

    //the timestamp starts at byte 40 of the received packet and is four bytes,
    // or two words, long. First, esxtract the two words:

    unsigned long highWord = word(packetBuffer[40], packetBuffer[41]);
    unsigned long lowWord = word(packetBuffer[42], packetBuffer[43]);
    // combine the four bytes (two words) into a long integer
    // this is NTP time (seconds since Jan 1 1900):
    unsigned long secsSince1900 = highWord << 16 | lowWord;
    Serial.print("Seconds since Jan 1 1900 = " );
    Serial.println(secsSince1900);

    // now convert NTP time into everyday time:
    Serial.print("Unix time = ");
    // Unix time starts on Jan 1 1970. In seconds, that's 2208988800:
    const unsigned long seventyYears = 2208988800UL;
    // subtract seventy years:
    unsigned long epoch = secsSince1900 - seventyYears;
    // print Unix time:
    Serial.println(epoch);


    // print the hour, minute and second:
    Serial.print("The UTC time is ");       // UTC is the time at Greenwich Meridian (GMT)
    Serial.print((epoch  % 86400L) / 3600); // print the hour (86400 equals secs per day)
    Serial.print(':');
    if ( ((epoch % 3600) / 60) < 10 ) {
      // In the first 10 minutes of each hour, we'll want a leading '0'
      Serial.print('0');
    }
    Serial.print((epoch  % 3600) / 60); // print the minute (3600 equals secs per minute)
    Serial.print(':');
    if ( (epoch % 60) < 10 ) {
      // In the first 10 seconds of each minute, we'll want a leading '0'
      Serial.print('0');
    }
    Serial.println(epoch % 60); // print the second
  }
  // wait ten seconds before asking for the time again
  delay(10000);
  Ethernet.maintain();
}

// send an NTP request to the time server at the given address
void sendNTPpacket(char* 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();
}
 char* sendNTPpacket(timeServer); // send an NTP packet to a time server

That is NOT calling a function. That is defining a function prototype.

The actual implementation of the function has a different signature.

Do you know what you are doing?

Hi Paul S, again thank you for your help. Truthfully, no I am very confused. I used the char* to get the code to compile so that I could see how far down the loop things were working. Without it, the error:

'sendNTPpacket' was not declared in this scope

is displayed immediately.

My code is now:

#include <SPI.h>
#include <Ethernet.h>
#include <EthernetUdp.h>

// Enter a MAC address for your controller below.
// Newer Ethernet shields have a MAC address printed on a sticker on the shield
#if defined(WIZ550io_WITH_MACADDRESS) // Use assigned MAC address of WIZ550io
;
#else
byte mac[] = {0x90, 0xA2, 0xDA, 0x10, 0x21, 0xCB};
#endif

unsigned int localPort = 8888;      // local port to listen for UDP packets

char timeServer[] = "time.nist.gov"; //NTP server

const int NTP_PACKET_SIZE = 48; // NTP time stamp is in the first 48 bytes of the message

byte packetBuffer[NTP_PACKET_SIZE]; //buffer to hold incoming and outgoing packets

// A UDP instance to let us send and receive packets over UDP
EthernetUDP Udp;

void setup()
{
  // Open serial communications and wait for port to open:
  Serial.begin(9600);
  Udp.begin(localPort);
}




void loop()
{
sendNTPpacket(timeServer); // send an NTP packet to a time server
  // wait to see if a reply is available
  delay(1000);
  if ( Udp.parsePacket() ) {
    // We've received a packet, read the data from it

    Udp.read(packetBuffer, NTP_PACKET_SIZE); // read the packet into the buffer

    //the timestamp starts at byte 40 of the received packet and is four bytes,
    // or two words, long. First, esxtract the two words:

    unsigned long highWord = word(packetBuffer[40], packetBuffer[41]);
    unsigned long lowWord = word(packetBuffer[42], packetBuffer[43]);
    // combine the four bytes (two words) into a long integer
    // this is NTP time (seconds since Jan 1 1900):
    unsigned long secsSince1900 = highWord << 16 | lowWord;
    Serial.print("Seconds since Jan 1 1900 = " );
    Serial.println(secsSince1900);

    // now convert NTP time into everyday time:
    Serial.print("Unix time = ");
    // Unix time starts on Jan 1 1970. In seconds, that's 2208988800:
    const unsigned long seventyYears = 2208988800UL;
    // subtract seventy years:
    unsigned long epoch = secsSince1900 - seventyYears;
    // print Unix time:
    Serial.println(epoch);


    // print the hour, minute and second:
    Serial.print("The UTC time is ");       // UTC is the time at Greenwich Meridian (GMT)
    Serial.print((epoch  % 86400L) / 3600); // print the hour (86400 equals secs per day)
    Serial.print(':');
    if ( ((epoch % 3600) / 60) < 10 ) {
      // In the first 10 minutes of each hour, we'll want a leading '0'
      Serial.print('0');
    }
    Serial.print((epoch  % 3600) / 60); // print the minute (3600 equals secs per minute)
    Serial.print(':');
    if ( (epoch % 60) < 10 ) {
      // In the first 10 seconds of each minute, we'll want a leading '0'
      Serial.print('0');
    }
    Serial.println(epoch % 60); // print the second
  }
  // wait ten seconds before asking for the time again
  delay(10000);
  Ethernet.maintain();
}

// send an NTP request to the time server at the given address
void sendNTPpacket(char* 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();
}

Still with no success :confused:

I downloaded 1.6.6, and copied and pasted your sketch. I get only one error:

Sketch uses 12,112 bytes (39%) of program storage space. Maximum is 30,720 bytes.
Global variables use 494 bytes (24%) of dynamic memory, leaving 1,554 bytes for local variables. Maximum is 2,048 bytes.

That's not an error, that's just a status message.

CrossRoads:
That's not an error, that's just a status message.

Damned. Forgot the quotes and smiley face. Again.

Agreed, 1.6.6 does compile and works out okay. Thank you for everyone's help. Good Day!

When I try to compile the correcred code I get the following error:
Arduino: 1.8.8 (Windows 7), Board: "Arduino/Genuino Uno"

C:\Users\DYNAVO~1\AppData\Local\Temp\cchdLaVg.ltrans2.ltrans.o: In function `main':

C:\Program Files\Arduino\hardware\arduino\avr\cores\arduino/main.cpp:46: undefined reference to `loop'

collect2.exe: error: ld returned 1 exit status

exit status 1
Error compiling for board Arduino/Genuino Uno.

This report would have more information with
"Show verbose output during compilation"
option enabled in File -> Preferences.

Does anyone know what's going on?