TCPClient.connected returns true until timeout on Photon HTTP request

Troubleshooting
1

Hi all,

I’m testing some very basic TCPClient code to do an HTTP request. The server should close the connection but this doesn’t happen and it times out after 2 minutes. Is this a bug with TCPClient?

#include "spark_wiring_tcpclient.h"
#include "application.h"
    
TCPClient client;
    
void setup() {
    while (!Serial.available()) {
        Serial.println("Press any key to start.");
        delay (1000);
    }
    
    if (client.connect("google.com", 80)) {
        Serial.println("connected");
        client.println("GET /search?q=arduino HTTP/1.1");
        client.println("Host: www.google.com");
        client.println("Connection: close");
        client.println();
    }
}
    
void loop() {
      // if there are incoming bytes available
      // from the server, read them and print them:
      if (client.available()) {
        char c = client.read();
        Serial.print(c);
      }
    
      // if the server's disconnected, stop the client:
      if (!client.connected()) {
        Serial.println();
        Serial.println("disconnecting.");
        client.stop();
    
        // do nothing forevermore:
        while(true);
    }
}

Thanks!
Kev

2

Is this for a core or photon? You also shouldn’t need the first include

3

Yes using a Photon. You’re also right that the #include “spark_wiring_tcpclient.h” isn’t required.

4

@JumpMaster, if you are compiling on the web IDE then I don't believe that client.connected() will correctly return FALSE when the server disconnects. I discussed this issue here:

The fix is available for those who compile locally but not on the web IDE yet. As a temporary fix, you can set a timeout so that when you receive nothing from the server for a set time (5 secs?), you do a client.stop().

5

That’s good to know. I’m submitting request to emoncms which gives a known reply. So I disconnect after receiving ok which will do for now.

Thanks!

1 Like
6

For HTTP transactions, you’re also probably better off using HttpClient library instead of TcpClient library.

Provides higher-level functions and seems fairly reliable in my experience so far.

1 Like