Fez T18 wifi request failed

SITCore SBC
22

And if you call again
wifi.SendHttpGet (“files.ghielectronics.com” …

home it works my first time but if I call SendHttpGet a second time it bug

23

With the new library the response should be read like this:
But it seems to be faulty as I get a http 400 response

var buffer = new byte[512];
    var start = DateTime.UtcNow;
    var code = wifi.SendHttpGet("files.ghielectronics.com", "/", 80,     SPWF04SxConnectionSecurityType.None);
    Debug.WriteLine($"HTTP {code}");
while (wifi.ReadResponseBody(buffer, 0, buffer.Length) is var read && read > 0)
        {
            total += read;
            try
            {
                Debugger.Log(0, "", Encoding.UTF8.GetString(buffer, 0, read));

            }
            catch
            {
                Debugger.Log(0, "", Encoding.UTF8.GetString(buffer, 0, read - 1));
            }
            Thread.Sleep(100);
        }
        Debug.WriteLine($"\r\nRead: {total:N0} in {(DateTime.UtcNow - start).TotalMilliseconds:N0}ms");
24

I have a response from domoticz and I get it with just these lines.
the problem is during the second request.

        var code = wifi.SendHttpGet("192.168.1.3", "/json.htm?type=command&param=switchlight&idx=1839&switchcmd=On", 8080, SPWF04SxConnectionSecurityType.None);
        Debug.WriteLine($"HTTP { code}");

        wifi.ReadResponseBody(buffer, 0, buffer.Length);
        string texte = Encoding.UTF8.GetString(buffer, 0, buffer.Length);
        Debug.WriteLine(texte);
25

With this url it works:

var code = wifi.SendHttpGet(“www.roschmionline.de”, “/”, 80, SPWF04SxConnectionSecurityType.None);
Debug.WriteLine($“HTTP {code}”);

26

You should be careful to read only a small part of the response, process this batch and then read the next batch, process it and so on. (Like in my example) The MCU has only few ram and this might be the problem.

27

the answer is very short, it is this:
{
“status” : “OK”,
“title” : “SwitchLight”
}

the problem comes even if we don’t read the answer.

28

for the site “www.roschmionline.de” I have a direct error in the execution of the request

29

during the second SendHttpGet the error provided the following information: Variable length response command already outstanding

with “www.google.com” I get the html code of the page without problem and all at once.

30

and @Dat_Tran i have no news from you.

31

with “www.google.com” I get the html code of the page without problem and all at once.

Do you mean no problem with google.com?

32

In my App with this code added in main()
after
wifi.ClearTlsServerRootCertificate();

        while (true)
        {
            int total = 0;
            var buffer = new byte[512];
            var start = DateTime.UtcNow;
            var code = wifi.SendHttpGet("www.google.com", "/", 80, SPWF04SxConnectionSecurityType.None);
            Debug.WriteLine($"HTTP {code}");
            while (wifi.ReadResponseBody(buffer, 0, buffer.Length) is var read && read > 0)
            {
                total += read;
                try
                {
                    Debugger.Log(0, "", Encoding.UTF8.GetString(buffer, 0, read));

                }
                catch
                {
                    Debugger.Log(0, "", Encoding.UTF8.GetString(buffer, 0, read - 1));
                }
                Thread.Sleep(100);
            }
            Debug.WriteLine($"\r\nRead: {total:N0} in {(DateTime.UtcNow - start).TotalMilliseconds:N0}ms");

            Thread.Sleep(5000);
        }

Runs and downloads ‘for ever’ (more than 20 times)

1 Like
33

I tested your program which therefore works very well. And I looked for which line was required for proper operation. when there is no more answer to read you have to read again, it must do something in the wifi chip.

1 Like
34 
           while (true)
            {
                int total = 0;
                var buffer = new byte[512];
                var buffer1 = new byte[512];
                var start = DateTime.UtcNow;
                var code = wifi.SendHttpGet("192.168.1.3", "/json.htm?type=command&param=switchlight&idx=1839&switchcmd=Toggle", 8080, SPWF04SxConnectionSecurityType.None);
                Debug.WriteLine($"HTTP {code}");
                total = wifi.ReadHttpResponse(buffer, 0, buffer.Length);
                total = wifi.ReadHttpResponse(buffer1, 0, buffer1.Length);
                
                Debug.WriteLine($"\r\nRead: {total:N0} in {(DateTime.UtcNow - start).TotalMilliseconds:N0}ms");

                Thread.Sleep(2000);
            }
1 Like
35

problem solved

1 Like
36

@ letailleur can you please share what problem was, please?

@ RoSchmi Thanks a lot :)).

37

The problem was that you couldn’t run SendHttpGet twice in a row. You must read the content of the response and read again (empty without response) so that the wifi chip is ready to send a new request.
Many thanks to @RoSchmi

my 15 students will be able to work

2 Likes
38

@letailleur happy to hear that it works now. If you should see problems in future you should consider to use the SPWF04S library from the Github dev branch. There were some issues fixed since Version 1.0.

The ReadHttpResponse command was exchanged against the new ReadResponseBody command.

@Dat_Tran Btw: Where is John ?