So I have an application that runs on the Arduino that passes info over serial. I'm using a ESP2866 to make it wireless.


I have a working java socket server, that I can connect to with other applications. (Java, c++, ext.) And even across the network.

I just cant seem to get my ESP2866 to connect.

Iv tried several ESP2866 units, no success. Iv tried updating the firmware on each, nope.

AT                      ->  OK
AT+RST                  ->  ready
AT+CWMODE=1             ->  OK
AT+CWJAP="name","pass"  ->  CONNECTED,GOTIP,OK
AT+CIPMUX=0             ->  OK
AT+CIFSR                ->
AT+CIPSTART="TCP","","4160"  ->  ERROR

The lack of debug info is... Aggravating. Iv Seen other examples of this that worked. So whats the problem?

Additional info:

netstat -tulpn | grep 4160
tcp6       0      0 :::4160          :::*      LISTEN      23058/java   

(Edit 1:)Just tried restricting to IPV4 and rebinding the port. Nope.

InetAddress localAddress = Inet4Address.getByAddress(new byte[]{(byte) 192,(byte) 168,0,9});
System.setProperty("java.net.preferIPv4Stack", "true");
ServerSocket listener = new ServerSocket(port,20,localAddress);
//...Code to make socket work.

The ESP trys to connect to port 4160, but the server is listing on port 20.

  • java.net.ServerSocket.ServerSocket(int port, int backlog, InetAddress bindAddr) throws IOException – Steven Venham Jun 2 '16 at 17:00
  • try just writing ServerSocket listener = new ServerSocket(port/ *4160*/); – wiomoc Jun 2 '16 at 17:06
  • is the port answer solved your problem? – rOr oRo Oct 31 '17 at 20:23

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