Revision 9:264e9d879cf5, committed 2021-04-24

Comitter:

timo_k2

Date:

Sat Apr 24 15:31:36 2021 +0000

Parent:

8:e500ff7ddcaf

Commit message:

Receives an UDP messages, reads the number of bytes and sends an UDP message back with the same number of bytes.

Changed in this revision

--- a/main.cpp	Sun Jan 17 20:11:12 2021 +0000
+++ b/main.cpp	Sat Apr 24 15:31:36 2021 +0000
@@ -7,15 +7,15 @@
  * An other microcontroller with "Round Trip Delay" will be needed. 
  * ST NUCLEO H743ZI2 used for testing.
  *   
- * Timo Karppinen 23.11.2020
+ * Timo Karppinen 24.04.2021
  ***********************************/
 #include "mbed.h"
 #include "EthernetInterface.h"
 
-
 #define REMOTE_PORT 5001    // The port numbers the other way round
 #define LOCAL_PORT 5000     // than in the "Round Trip Delay"
-#define BUFF_SIZE 128  // test with 32, 128, 512, etc
+#define BUFF_SIZE 1024  // 512 can be takes as largest UDP byte number. 
+int UDP_SIZE = 128;    // the actual size will be taken from incoming message
 
 //Network interface
 EthernetInterface net;
@@ -45,8 +45,6 @@
 
 char out_data[BUFF_SIZE]; 
 
-//using namespace std::chrono;
-
 Timer armedFor;
     
 int main() {
@@ -54,8 +52,8 @@
     printf("\nEcho for the Round Trip Delay application (using Ethernet)\r\n");
 
     //Bring up the network interface
-    //eth.set_network(IP_Adress,GATEWAY,MASK);
-    net.set_network("192.168.1.12","192.168.1.1","255.255.252.0");
+    //eth.set_network(IP_Adress,MASK,GATEWAY);
+    net.set_network("192.168.1.12","255.255.252.0","192.168.1.1");
     net.connect();
     
     // Show network address
@@ -75,35 +73,37 @@
     
     //send_thread.start(udpSend);
     printf("Sending out \"Echo\" data to port number %d", REMOTE_PORT);
-    printf(" will be armed for triggering by pushing Blue button.\n");
-    printf("The IP is taken from the incoming message \n");
+    printf("Will be armed for triggering by pushing Blue button.\n");
+    printf("The IP for the \"Delay metering station\" is fixed! \n");
   
     while(1) {  
     sw2state = sw2.read();
-    printf( "\nsw2state is  %d\n", sw2state);
+    printf( "\nsw2  %d  - ", sw2state); 
+    printf("Not listening - Push the blue button!\n");
     
     if((sw2state == 1)&&(sw2state != sw2old)) {
         led2.write(1);
         armedFor.reset();   // reset timer to zero
         armedFor.start();
-        snprintf(out_data, BUFF_SIZE, "Echo -server listening for 8 sec" );
+        snprintf(out_data, BUFF_SIZE, "Echo -server listening for 60 sec" );
         clientUDP.set_port(REMOTE_PORT);
         udpSend();
          
-        snprintf(out_data, BUFF_SIZE, "Echo" );
+        snprintf(out_data, UDP_SIZE, "Echo" ); // Updates size on pushing sw2.
         
         // Start polling for the incoming "Echo" UDP datagram   
-        while ( armedFor.elapsed_time().count() < 8000000 ){
+        while ( armedFor.elapsed_time().count() < 60000000 ){
+            //snprintf(out_data, UDP_SIZE, "Echo" );
             if((newDatagram == 1)&&(newDatagram != newDatagramOld)){
-                char firstChar;
-                firstChar = in_data[0];
-                if (firstChar == 85){    // ASCII symbol 85 = "U" for the incoming
+                //char firstChar;
+                //firstChar = in_data[0];
+                //if (firstChar == 85){    // ASCII symbol 85 = "U" for the incoming
                     udpSend();      // Sending out first and then printing!
                     //printf( "firstChar: %s\n", &firstChar);
-                    } 
+                 //   } 
             }
             newDatagramOld = newDatagram; //Sending the "Echo" once only.  
-            newDatagram = 0; 
+            newDatagram = 0;
         }
     }
     sw2old = sw2state; // Once only with pushing the button as long as you like.
@@ -120,12 +120,13 @@
 
 // The functions
   
-
 void udpReceive()
 {
     int bytes;
     while(1) {
         bytes = serverUDP.recvfrom(&clientUDP, &in_data, BUFF_SIZE);
+        //ThisThread::sleep_for(100ms); // For testing only! Comment this line!
+        UDP_SIZE = bytes;   // updated for the responce 
         newDatagram = 1;    // set this before using time for printing
         ThisThread::sleep_for(100ms);
         printf("\n");
@@ -139,11 +140,11 @@
 void udpSend()
 {
         //char out_data[BUFF_SIZE];
-        
         //snprintf(out_data, BUFF_SIZE, "Echo" );
         //clientUDP.set_port(REMOTE_PORT);
-        serverUDP.sendto(clientUDP, out_data, sizeof(out_data));
+        //ThisThread::sleep_for(200ms); // For testing only! Comment this line!
+        serverUDP.sendto(clientUDP, out_data, UDP_SIZE);
         printf("Sending out: %s\n", out_data);
-        printf("with %d" , sizeof(out_data));
+        printf("with %d" , UDP_SIZE);
         printf(" data bytes in UDP datagram\n");   
 }
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