nRF9160 DK HTTP POST to my Webserver

[Hoang]

Dear , 

I want to use LTE_M of nRF9160 DK to POST to my webserver

Do you have any suggestions?

Thanks, 

Regards

hng

[Vidar Berg]

Hi,

Please see my response here: https://devzone.nordicsemi.com/f/nordic-q-a/46094/how-to-make-http-post-no-libcurl 

Regards,

Vidar

[Hoang]

Thank Vidar,

I will try it 

Regards,

hng

[Hoang]

It works, just fixed a little bit: 

/******************************************"**************************************/
#define MAXLINE 4096
#define HTTP_HOST "142.xx.xx.192"  //my webserver
#define HTTP_PORT 80
#define HTTP_PATH "/"
#define TEST_STRING  "Hello from nRF9160 DK"

#define POST_TEMPLATE "POST %s? HTTP/1.1\r\n"\
		"Host: %s\r\n"\
		"Connection: keep-alive\r\n"\
	        "Content-type: application/x-www-form-urlencoded\r\n"\
		"Content-length: %d\r\n\r\n"\
		"%s"
/************************************************************************/
void app_http_post()
{  
	//int err; 
    struct sockaddr_in local_addr;
	struct addrinfo *res;

	local_addr.sin_family = AF_INET;
	local_addr.sin_port = htons(0);
	local_addr.sin_addr.s_addr = 0;

	      
	int err = getaddrinfo(HTTP_HOST, NULL, NULL, &res);

	printk("getaddrinfo err: %d\n\r", err);
	((struct sockaddr_in *)res->ai_addr)->sin_port = htons(HTTP_PORT);
        
        char send_buf[MAXLINE + 1];
	
	int send_data_len_post = snprintf(send_buf,
				         500, /*total length should not exceed MTU size*/
				         POST_TEMPLATE, HTTP_PATH,
				         HTTP_HOST, strlen(TEST_STRING),
				         TEST_STRING);

	printk("send err: %d\n\r", send_data_len_post);


	int client_fd = socket(AF_INET, SOCK_STREAM, 0);

	printk("client_fd: %d\n\r", client_fd);
	err = bind(client_fd, (struct sockaddr *)&local_addr,
		   sizeof(local_addr));
	printk("bind err: %d\n\r", err);
        // connect
	err = blocking_connect(client_fd, (struct sockaddr *)res->ai_addr,
			       sizeof(struct sockaddr_in));
	printk("connect err: %d\n\r", err);
       //send
    blocking_send(client_fd, send_buf, send_data_len_post, 0);
    k_sleep(1000);
       
	printk("\n\r HTTP POST Finished. \n\r");
	close(client_fd);

}

Thanks so much

Regards, 

hng

[Vidar Berg]

Thanks for sharing the solution here. 

[Hoang]

DearVidar Berg

I tried to run this http post in a loop

first, i will check the LTE_M signal "AT+CEREG?"

It returns:  

Checking LTE_M signal.............

+CEREG: 0,5,"765D","0110C303",7

OK

Found the LTE_M signal 
Closing socket

  find LTE_M signal........... 
Checking LTE_M signal.............

+CEREG: 0,5,"765D","0110C303",7

OK

Found the LTE_M signal 
Closing socket

  find LTE_M signal........... 
Checking LTE_M signal.............

+CEREG: 0,5,"765D","0110C303",7

OK

Found the LTE_M signal 
Closing socket

  find LTE_M signal........... 
Checking LTE_M signal.............

+CEREG: 0,5,"765D","0110C303",7

OK

Found the LTE_M signal 
Closing socket

  find LTE_M signal........... 
Checking LTE_M signal.............

+CEREG: 0,5,"765D","0110C303",7

OK

Found the LTE_M signal 
Closing socket

  find LTE_M signal........... 
Checking LTE_M signal.............

+CEREG: 0,5,"765D","0110C303",7

OK

Found the LTE_M signal 
Closing socket

  find LTE_M signal........... 
Checking LTE_M signal.............

+CEREG: 0,5,"765D","0110C303",7

OK

Found the LTE_M signal 
Closing socket

  find LTE_M signal........... 
Checking LTE_M signal.............

Closing socket

 Couldnt find LTE_M signal........... 
Checking LTE_M signal.............

Closing socket

 Couldnt find LTE_M signal........... 
Checking LTE_M signal.............

After 7times, "AT+CEREG?" return NOTHING!

Why is the problem, the buffer is full? or something wrong in my code? 

Plz help me. 

Thanks so much 

Regards, 

hng

[Vidar Berg]

I believe a bug in the BSD library causes this. I get the "no memory" error when call socket send in a loop without any delay in-between. I have reported this internally. A workaround, for now, is to add a delay between each post request. 

[Hoang]

Dear Vidar Berg

I had 2s delay between

How long should I add ?

Thanks for fast responds, 

Regards, 

hng

[Vidar Berg]

A 2-second delay should be sufficient. Can you try to increase the stack sizes in your project *.conf file?

e.g.,

CONFIG_MAIN_STACK_SIZE= 8192

CONFIG_HEAP_MEM_POOL_SIZE=8192

[Hoang]

Dear Vidar Berg

I tried, the same thing happened  

int nRF_LTE_check(void)
{
    int err;
    const char *ATREG="AT+CEREG?"; 
	int at_socket_fd = socket(AF_LTE, 0, NPROTO_AT);
    printk("Checking LTE_M signal.............\n\r");

	if (at_socket_fd < 0) {
		err = 1; 
	}
    else {
    int bytes_written = send(at_socket_fd, ATREG, strlen(ATREG), 0);
    if (bytes_written > 0) {
	int r_bytes = blocking_recv(at_socket_fd, recv_buf,sizeof(recv_buf), MSG_DONTWAIT);
	if (r_bytes > 0) {
	printk("%s", recv_buf);
    if (recv_buf== LTEfound) 
       {
      err = 0; 
      printk("Found LTE_M signal \n");
        }
    else {
       printk("Couldnt find the LTE_M signal \n");
       err =1;
        }
 }
  }
          }
	printk("Closing socket\n\r");
    (void)close(at_socket_fd);
    return err; 
}

my loop: 

#include <zephyr.h>
#include <net/socket.h>
#include <misc/printk.h>
#include <zephyr/types.h>
#include <math.h>
#include <uart.h>
#include <soc.h>
#include <gpio.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>     /* atof */
#include <autoconf.h>

void main (void)
{
  printk("Test is starting \n"); 

   
    
    while(1){

   
      int lte_err= nRF_LTE_check();
      if(lte_err==0){ printk("  find LTE_M signal........... \n"); }
      else{ printk(" Couldnt find LTE_M signal........... \n");}
      k_sleep(2000);
   
    }
   
}

and my prj.conf

CONFIG_SERIAL=y
CONFIG_TRUSTED_EXECUTION_NONSECURE=y
CONFIG_UART_INTERRUPT_DRIVEN=y
CONFIG_UART_1_NRF_UARTE=y
CONFIG_UART_2_NRF_UARTE=y

CONFIG_GPIO=y

CONFIG_NETWORKING=y
CONFIG_NET_BUF_USER_DATA_SIZE=1
CONFIG_NET_SOCKETS_OFFLOAD=y
CONFIG_NET_SOCKETS=y
CONFIG_NET_SOCKETS_POSIX_NAMES=y
CONFIG_NET_RAW_MODE=y
CONFIG_BSD_LIBRARY=y


CONFIG_STDOUT_CONSOLE=y

CONFIG_TEST_RANDOM_GENERATOR=y

CONFIG_LOG=n
CONFIG_LOG_DEFAULT_LEVEL=4
#CONFIG_HEAP_MEM_POOL_SIZE=1024
CONFIG_MAIN_STACK_SIZE= 8192
CONFIG_HEAP_MEM_POOL_SIZE=8192


# LTE link control
#CONFIG_LTE_LINK_CONTROL=y
CONFIG_UART_2_NRF_TX_BUFFER_SIZE=1024

[Vidar Berg]

Can you upload your entire project directory here so I can try to debug it? Some of the variable definitions are missing from the code snippets above.