5 years, 12 months ago.

the UDPsocket receivefrom methode of EthernetInterface is not working

hello everybody I wonder if somebody already used the UDPSocket of EthernetInterface library. In fact I am stacked with the socket.receivefrom that doesn't wont to work. I want to send and receive data through UDP to and from a real time windows target simulik Matlab module. I prepared my module that I tested with a small software, it sends and receives data with no problem my code follows this logic:

• create an EthernetInterface object (eth), initiate it with eth.init() to a specific IP address with a specific Mask and Gate, then connect with eth.connect(). this goes well because both methods returns '0' and I can ping my mbed from my PC;
• create a UDPSocket 'sock' and bind it to a specific port '1820' using the sock.bin() function, this goes good to because it is displaying a '0' on my LCD screen (I have mbed application board);
• create an endpoint and set its address to my PC's address and its port to a specific port (1819);
• here, if I send a buffer using sock.sendto(), it goes very good and I'm receiving data on my matlab module, but if I try to receive data the mbed goes on an infinite sleep, and it doesn't even give an error code when debugging using the keil debugguer, I found that the socket doesn't find any "lastdata" left and it looks like the code looses its way while trying to find an error code. this is my code

#include "mbed.h"
#include "EthernetInterface.h"
#include "C12832.h"
 C12832 lcd(p5, p7, p6, p8, p11);
 
int main() {

    EthernetInterface eth;
    lcd.cls();	
    lcd.locate(0,3);
    lcd.printf("Eth %d",eth.init("172.16.100.136", "255.255.255.0", "172.16.100.134")); //here every thing goes well and I have 0 on my 
                                                                                                                                                                                               // lcd
    lcd.locate(40,3);
    lcd.printf("Cnx %d",eth.connect()); // we have 0 here too
    

		
    UDPSocket sock;
    lcd.locate(80,3);
    lcd.printf("bind %d",sock.bind(1820)); //here is ok, we have 0 too
		sock.set_broadcasting(1);
		sock.set_blocking(1);
	      
    Endpoint nist;
    nist.set_address("172.16.100.139", 1819);
    char in_buffer;


    
    char out_buffer[] = {11, 12, 13, 14, 15, 16, 17, 18}; // Does not matter
    lcd.locate(0,15);
    lcd.printf("send %d",sock.sendTo(nist, out_buffer, sizeof(out_buffer))); //here is ok, I have 8, the number of the sent cararters
                                                                                                                                                                //and I receive the data on matlab
    int n;
    lcd.locate(40,15);
    n = sock.receiveFrom(nist, &in_buffer, 1); //here it sleeps for ever
    lcd.printf("receive %d",n);//I never get this printf 
		

 

    sock.close();
    
   // eth.disconnect();
    while(1) {}
}

same result either I use bind() or init(), either I initiate the endpoint address or not, either I use one socket or two, one endpoint or two or whatever when I go to the sockets.c file and I remove the line that goes to look for the error(line 594), the code doesn't sleep but neither receives any data, the sock.receivefrom just returns -1. help please