ESP8266 Community Forum

- Mon Feb 06, 2017 1:29 pm #62176 Greetings. I have not been able to google the solution to my problem. I'm a esp8266-newbie, and I want to make sure the esp8266 is reliable enough for my needs, so naturally I want to test how quickly and how many connections the esp8266 can handle - serially.

Here is my attempt at a TCP-server, which should answer incoming telnet-connections to port 88 and just output an increasing counter, disregarding any input. My counter gets to around 252, and after that the esp8266 does still accept and terminate the connections, but does not output the text or number anymore. So to me this problem seems to be that I am terminating the connection wrongly, that some data gets accumulated until all 256 bytes of (something) are used up. NB: if I wait several minutes (by terminating the telnet-loop and later restarting it, while doing nothing to the esp8266) the counting sometimes continues with count-values > 1000, and sometimes the esp8266 has completely restarted with count 0 again...

So the question is, how to properly terminate a connection, completely erasing any leftover data from the previous one?

The way I'm testing this is by using a telnet-loop from my raspberry, giving the following output:

Code: Select allpi@raspberrypi ~ $ while true; do telnet 192.168.2.112 88 ; done

...
Trying 192.168.2.112...
Connected to 192.168.2.112.
Escape character is '^]'.
Count: 250
Connection closed by foreign host.
Trying 192.168.2.112...
Connected to 192.168.2.112.
Escape character is '^]'.
Count: 251
Connection closed by foreign host.
Trying 192.168.2.112...
Connected to 192.168.2.112.
Escape character is '^]'.
Count: 252
Connection closed by foreign host.
Trying 192.168.2.112...
Connected to 192.168.2.112.
Escape character is '^]'.
Connection closed by foreign host.
Trying 192.168.2.112...
Connected to 192.168.2.112.
Escape character is '^]'.
Connection closed by foreign host.
...


And the testcode:

Code: Select all#include <ESP8266WiFi.h>

WiFiServer server(88);
long count;

void setup()
{
  count=0;
  WiFi.mode(WIFI_STA);
  WiFi.begin("xxx", "yyy");
  while (WiFi.status() != WL_CONNECTED)
  {
    delay(200);
  }
  server.begin();
}

void loop()
{
  WiFiClient client = server.available();
  if (client)
  {
    if (client.connected())
    {
      count++;
      client.print("Count: ");
      client.println(count);
      client.stop();
    }
  }
}


(I have also tried flushing any incoming data before client.stop() in the code above, by trying

Code: Select all      while(client.available())
      {
        client.read();
      }
      delay(50);
      client.flush();


and similar... Same result.)