AM2634: UDP Client Implementation

Hi Aakash V,

Can you please confirm the follwing. Not sure if I have the bandwidth right now to go through the whole code.

1. Can you check lwip_stats (enter "lwip_stats") in CCS expressions window. Don't send any data from MCU to PC, only send data from PC to MCU (the case which you mentioned fails). Inside LwIP stats, check for memory related errors or UDP errors.

Regards,
Shaunak

Hi Shaunak,

I tested with lwip_stats in expression i couldn't able to get the value.

can you please check the zip file of my project which i mentioned above.

Hi Aakash V, 

1. You need to pause your core and then check the stats.

2. Just a request, the next time you send an application that has been modified by you, it would be great if you share some information about the modifications, code additions made by you/Lotus-Wireless. It is very difficult to just take a "zip" of your project and debug something which you have implemented without any walk-through of the code or any background on how you are testing it. I, at TI, am completely unaware of what you are doing. Also I recommend cleaning up your code (removing the API calls for httpd_init and the files for http server (as far as I am aware you are not using the HTTP server, but it would consume lwip pbufs and memory).

3. You need to give me some inputs on how do you test the application that you have modified, I run an NCAT server on my linux PC connected to Port-1, I see no data coming onto server from client. I see that you have 2 MAC ports enabled. Which MAC port communicates with the UDP server? I see that the IP for the server is hard-coded to "192.168.2.2" but the netif for MAC port -1 gets IP address dynamically? Can you send some more information? 

Regards,
Shaunak

Hi Shaunak,

1. I did Modifications are comment existing http_server application (add udp init, udp send udp receive) functions only rest of the things are same, i removed this fuctions HTTP server function as per your suggestion.

#include "lwip/pbuf.h"
#include "lwip/udp.h"
#include "lwip/tcp.h"

#include "stdio.h"
#include "string.h"


void udp_receive_callback(void *arg, struct udp_pcb *upcb, struct pbuf *p, const ip_addr_t *addr, u16_t port);
static void udpClient_send(void);

struct udp_pcb *upcb;
char buffer[100];
int counter = 0;

/* IMPLEMENTATION FOR UDP CLIENT :   source:https://www.geeksforgeeks.org/udp-server-client-implementation-c/

1. Create UDP socket.
2. Send message to server.
3. Wait until response from server is received.
4. Process reply and go back to step 2, if necessary.
5. Close socket descriptor and exit.
*/


void udpClient_connect(void)
{
    err_t err;

    /* 1. Create a new UDP control block  */
    upcb = udp_new();

    /* Bind the block to module's IP and port */
    ip_addr_t myIPaddr;
    IP_ADDR4(&myIPaddr, 192, 168, 2, 200);
    udp_bind(upcb, &myIPaddr, 8);


    /* configure destination IP address and port */
    ip_addr_t DestIPaddr;
    IP_ADDR4(&DestIPaddr, 192, 168, 2, 2);
    err= udp_connect(upcb, &DestIPaddr, 7);

    if (err == ERR_OK)
    {
        /* 2. Send message to server */
        udpClient_send ();

        /* 3. Set a receive callback for the upcb */
        udp_recv(upcb, udp_receive_callback, NULL);
    }
}

static void udpClient_send(void)
{
  struct pbuf *txBuf;
  char data[100];

  int len = sprintf(data, "sending UDP client message %d", counter);

  /* allocate pbuf from pool*/
  txBuf = pbuf_alloc(PBUF_TRANSPORT, len, PBUF_RAM);

  if (txBuf != NULL)
  {
    /* copy data to pbuf */
    pbuf_take(txBuf, data, len);

    /* send udp data */
    udp_send(upcb, txBuf);

    /* free pbuf */
    pbuf_free(txBuf);
  }
}


void udp_receive_callback(void *arg, struct udp_pcb *upcb, struct pbuf *p, const ip_addr_t *addr, u16_t port)
{
    /* Copy the data from the pbuf */
    strncpy (buffer, (char *)p->payload, p->len);

    /*increment message count */
    counter++;

    /* Free receive pbuf */
    pbuf_free(p);
}

My requirement to achieve :  when ever this line udp_recv() this should call this udp_receive_callback() function when ever send "hello" or any data but not triggering. so kindly explain this reason for this.

3.   Hercules/sockettest software are using on windows platform.

Hi Shaunak,

Thank you for your early replay,

Is the UdpClientSend() function a blocking call? Can you try to comment the udp send function and just try to receive data using udp_recv and confirm that when sending is disabled and only UDP receiving is enabled, you are still not able to receive data?

yes, i commented this UdpClientSend() so udp_recv() it is working fine. so, is there any other logic if you know kindly say. because i need to edit in this project only.