Diff: main.cpp

Revision:

4:4118d38b68e1

Parent:

3:fb39c8c13b34

Child:

5:837b2680bebb

--- a/main.cpp	Mon Nov 23 12:48:48 2020 +0000
+++ b/main.cpp	Sun Jan 17 19:09:05 2021 +0000
@@ -2,12 +2,14 @@
  * Copyright (c) 2006-2020 Arm Limited and affiliates.
  * SPDX-License-Identifier: Apache-2.0
  ***********************************
- * Round trip delay meter. Date and time is taken from a NTP server. 
+ * Round trip delay meter.
+ * Mbed OS Timer with microsecond precision used for a stopwatch.  
  * A microcontroller board with an Ethernet interface.
+ * For measuring documentation the date and time is taken from a NTP server.
  * An other microcontroller with "Round trip echo" will be needed. 
  * NXP FRDM-K64F used for testing.
  *   
- * Timo Karppinen 20.11.2020
+ * Timo Karppinen 17.1.2021
  ***********************************/
 #include "mbed.h"
 #include "EthernetInterface.h"
@@ -15,50 +17,50 @@
 
 #define REMOTE_PORT 5000
 #define LOCAL_PORT 5001
-#define BUFF_SIZE 128
+#define BUFF_SIZE 128  // test with 32, 128, 512, etc
 
 //Network interface
 EthernetInterface net;
 
 //Threads
-    Thread ntp_thread;
     Thread recv_thread;
-    Thread send_thread; 
-    
+
 // UDP
 SocketAddress clientUDP;  // Client on remote device
 UDPSocket serverUDP;   // UDP server in this device
 
-
 //NTP server is a time server used for delivering timing information for networks.
-// Returns 32 bits for seconds and 32 bits for fraction of seconds. 
+//Returns 32 bits for seconds and 32 bits for fraction of seconds. 
 //#define ntpAddress "2.pool.ntp.org"
 #define ntpAddress "time.mikes.fi"  // The VTT Mikes in Helsinki
 #define ntpPort 123
+// The address and port number can be replaced with the ones for the local 
+// network NTP server. 
 
 // Functions
-time_t getNTP();
+//time_t getNTP();
 void udpReceive( void );
 void udpSend( void );
 
 DigitalIn sw2(SW2);     // sw2 on K64F, button pressed = FALSE
-DigitalOut led2(LED2);  // RGB LED green on K64F
+DigitalOut led2(LED2);  // RGB LED on K64F, FALSE = Green
 int sw2state = 0;
 int sw2old = 1;
 
 char in_data[BUFF_SIZE];
 int newDatagram = 0;
 int newDatagramOld = 0;
-time_t timeNTP = 0;
+//time_t timeNTP = 0;
 
-//using namespace std::chrono;
-Timer stopwatch;
+Timer stopwatch; // Timer is an operating system class since OS 6.0
 Timer armedFor;
     
 int main() {
     printf("\nRound trip delay in UDP messaging (using Ethernet)\n");
     
     //Bring up the network interface
+    //eth.set_network(IP_Adress,GATEWAY,MASK); // leave out if using DHCP
+    net.set_network("192.168.1.10","192.168.1.1","255.255.252.0");
     net.connect();
     
     // Show network address
@@ -66,8 +68,12 @@
     net.get_ip_address(&netAddress);
     printf("\n\n NTPClient - UDPServer IP Address: %s\n", netAddress.get_ip_address() ? netAddress.get_ip_address():"None");
     
-    // NTP client at ntp thread
-    ntp_thread.start(getNTP);
+   
+    // NTP client 
+    
+    //printf("Message to NTP time server...\n");
+    //timeNTP = getNTP();
+    //printf("Current time in day month hour.min.sec year is  %s\r\n", ctime(&timeNTP));
     
     // UDP server 
     
@@ -77,56 +83,50 @@
     
     recv_thread.start(udpReceive);
     printf("Listening has been started at port number %d\n", LOCAL_PORT);
-    
-    send_thread.start(udpSend);
-    printf("Sending out demo data to port number %d", REMOTE_PORT);
-    printf(" has been started.\n");
+    printf("The operator for the \"Echo board\" should send a message!\n ");
     printf("The IP will be taken from the incoming message\n");
+    printf("Press the blue switch after receiving \"Echo server listening\"\n");
   
-
     while(1) {  
     sw2state = sw2.read();
-    printf( "\nsw2state is  %d\n", sw2state);
+    printf( "\nsw2state is  %d\n", sw2state); // Printing showing "I am alive".
     
-    if((sw2state == 0)&&(sw2state != sw2old)) {
-        led2.write(0);
+    if((sw2state == 0)&&(sw2state != sw2old)) {   // Note! Checking for FALSE sw
+        led2.write(1);
         armedFor.reset();   // reset timer to zero
         stopwatch.reset();   // reset stopwatch timer to zero
-        timeNTP = getNTP();
+        //timeNTP = getNTP();
         armedFor.start();
-        stopwatch.start();
+        //stopwatch.start();  // moved to udpSend subroutine
         udpSend();
         
     
-        // Start polling for the incomening "Echo" UDP datagram   
+        // Start polling for the incoming "Echo" UDP datagram   
         while ( armedFor.elapsed_time().count() < 8000000 ){
             if((newDatagram == 1)&&(newDatagram != newDatagramOld)){
+                stopwatch.stop(); 
                 char firstChar;
                 firstChar = in_data[0];
-                if (firstChar == 69){    // ASCII symbol 69 = "E" for the Echo
-                    stopwatch.stop();
-                    printf( "firstChar: %s\n", &firstChar);
-                    }
+                printf( "firstChar: %s\n", &firstChar);
                 for (int k =0; k < BUFF_SIZE; k++){
                     in_data[k] = 0;
-                    }  
+                    } 
             }
-            newDatagramOld = newDatagram; //Reading the stopwatch once only
-             
+            newDatagramOld = newDatagram; //Reading the stopwatch once only 
+            newDatagram = 0;   
         }
         
         // printing for testing. Replace with writing once to a SD memory card.
-        printf("Current time in day month hour.min.sec year is  %s\r\n", ctime(&timeNTP));
+        //printf("Measured at ( day month hour.min.sec year ) %s\r\n", ctime(&timeNTP));
         printf("The time taken was %llu microseconds\n", stopwatch.elapsed_time().count());
+        
     }
-    newDatagram = 0;
     sw2old = sw2state; // Once only with pushing the button as long as you like.
-    led2.write(1);
+    led2.write(0);
     armedFor.stop();
     stopwatch.stop();  // Stop the stopwatch if we did not receive the echo.
     
-    printf("\nWe stopped sending more UDP packets to the server.\nYou can unplug your device!\n");
-    ThisThread::sleep_for(4000ms);
+    ThisThread::sleep_for(1000ms);
     }
 }
 
@@ -140,10 +140,10 @@
         printf("An error occurred when getting the time. Code: %u\r\n", timestamp);
     } 
     else {     // the printings for testing only!
-        //printf("The timestamp seconds from the NTP server in\r\n  32 bit hexadecimal number is %X\r\n", timestamp);
-        //printf("  decimal number is %u\r\n", timestamp);
+        printf("The timestamp seconds from the NTP server in\r\n  32 bit hexadecimal number is %X\r\n", timestamp);
+        printf("  decimal number is %u\r\n", timestamp);
         timestamp += (60*60*2);  //  GMT +2  for Finland for the winter time.
-        //printf("Current time is %s\r\n", ctime(&timestamp));
+        printf("Current time is %s\r\n", ctime(&timestamp));
     } 
     return timestamp; 
 }
@@ -154,6 +154,7 @@
     while(1) {
         bytes = serverUDP.recvfrom(&clientUDP, &in_data, BUFF_SIZE);
         newDatagram = 1;    // set this before using time for printing
+        ThisThread::sleep_for(400ms); // waiting for the print buffer
         printf("\n");
         printf("bytes received: %d\n",bytes);
         printf("string: %s\n",in_data);
@@ -168,10 +169,10 @@
         char out_data[BUFF_SIZE];
         
         snprintf(out_data, BUFF_SIZE, "UDP message for getting the Echo" );
-        clientUDP.set_port(REMOTE_PORT);
-        serverUDP.sendto(clientUDP, out_data, sizeof(out_data));
         printf("Sending out: %s\n", out_data);
         printf("with %d" , sizeof(out_data));
         printf(" data bytes in UDP datagram\n");
-        
-}
+        clientUDP.set_port(REMOTE_PORT);
+        stopwatch.start();  // starting the stopwatch after preparations are done
+        serverUDP.sendto(clientUDP, out_data, sizeof(out_data)); 
+}
\ No newline at end of file