AVR Freaks

Thanks for your reply.

I followed your suggestions but I am still not clear on how can I post data to a web server and then get a reply back.

1. as Http client needs connect function to attach a socket with server's IP address. Now my question is:who is my server? Atmel board's static IP address or currencyconverter.kowabunga.net ?

2. Is the following code correct for the http initialization?

void httpd_init(void)
{
  
    struct tcp_pcb *client_pcb;
    struct ip_addr remoteIP;
    IP4_ADDR(&remoteIP, ETHERNET_CONF_REMOTE_IPADDR0, ETHERNET_CONF_REMOTE_IPADDR1,
    ETHERNET_CONF_REMOTE_IPADDR2, ETHERNET_CONF_REMOTE_IPADDR3);

}

3. Also please see if the http request function is missing information.

static err_t http_request(void *arg, struct tcp_pcb *pcb, struct pbuf *p, err_t err)
{
    char *string="POST /converter.asmx/GetCurrencyRate HTTP/1.1\r\nHost: currencyconverter.kowabunga.net\r\nContent-Type: application/x-www-form-urlencoded\r\nContent-Length: 32\r\n\r\nCurrency=CAD&RateDate=2019-02-25\r\n\r\n";
    
    tcp_write(pcb, string, strlen(string), TCP_WRITE_FLAG_COPY);
     /* now send */
    tcp_output(pcb);
    tcp_recv(pcb, http_recv);

    return ERR_OK;  
}

If you can provide me reference to an example that is posting data to server and displaying results on a web browser that would be great. As I have spent weeks to search a post example code using atmel board and I couldn't find something relevant.

Thanks in advance.

Thanks for the reply.

I am still not able to set up connection with server  www.currencyconverter.kowabunga.net .

As TCP connect function tcp_connect(pcb, &resolvedIP, 80, hc_connected) requires a resolved IP address of web server. 

I want to use DNS server that can resolve IP address from a host name.

   dns_gethostbyname("www.currencyconverter.kowabunga.net", &resolvedIP, NULL, NULL);

When I use above function to get a IP address from DNS server it returns the Atmel board static IP address. 

The DNS server address that I am using is the one that I got from typing ipconfig /all command in command prompt of my pc

#define DNS_SERVER_ADDRESS(ipaddr)        (ip4_addr_set_u32(ipaddr, ipaddr_addr("10.28.16.5"))) /* windows DNS */

The default DNS server address that was given in atmel code was the following:

#define DNS_SERVER_ADDRESS(ipaddr)        (ip4_addr_set_u32(ipaddr, ipaddr_addr("208.67.222.222"))) /* resolver1.opendns.com */

What DNS server address should I use?

Please help if you have information on how to resolve IP address from a host name using DNS.

Hi

Now after resolving the IP address of web server, I am using that in tcp_connect function to set up a connection between web server and atmel board (client).

But the response from the web server that I received is server unavailable error 503.

I tried to access websites like google.com and I got the same server error response in my code.

Please help me if you know how can I resolve this server error.

Thanks for reply.

I am using my company's LAN connection. Windows firewall settings are enabled and being managed by third party software.

What should I do in my code to connect with web server address if firewall is enabled?

Thanks for the reply Kartman. 

End result is, I have to access an internal web server so hopefully then I won't have firewall issue. 

With other external websites my connection is successful. So I will proceed further when I get that internal web server up and running.

Thank you for your help Kartman.

I got my code working now. I am able to set up a successful connection with internal server and getting 200 OK response back. 

As destination URL is within internal network of my company, I don't need proxy server or firewall changes.

So code is able to set up a direct connection with internal destination IP address.

I really appreciate your time and consideration.