.. _lwip_tcpecho_freertos:

lwip_tcpecho_freertos
==========================================

Overview
--------

This example shows TCP echo communication on FreeRTOS.

- PC sends TCP data frames to MCU,  and then MCU sends the data frames back to PC

Board Settings
--------------

- Connect a USB port on PC to the PWR DEBUG port on the development board with a USB Type-C cable

- Connect an Ethernet port on PC to a RGMII port or a RMII port on the development board with an Ethernet cable

Project Configurations
----------------------

- Ethernet Port Settings: Refer to :ref:`Ethernet common project settings <ethernet_port_configurations_en>`

- Ethernet DHCP Configurations

  - the configurations in the `CMakeLists.txt` as follows:

    - sdk_compile_definitions(-DLWIP_DHCP=0): Disable DHCP feature

    - sdk_compile_definitions(-DLWIP_DHCP=1): Enable DHCP feature

Run Example
-----------

- Compiling and Downloading

- Running log is shown in the serial terminal as follows:


  .. code-block:: console

        This is an ethernet demo: TCP Echo on FreeRTOS
        LwIP Version: 2.1.2
        Enet phy init passed !
        Link Status: Down
        Link Status: Up
        Link Speed:  1000Mbps
        Link Duplex: Full duplex
        IPv4 Address: 192.168.100.10
        IPv4 Netmask: 255.255.255.0
        IPv4 Gateway: 192.168.100.1



- Run an Ethernet debugging tool

  - create and set a TCP client:  TCP Server IP: 192.168.100.10/Port: 5001

    **Note: There is a necessary adjustment for Server IP according to the segment of  LAN where PC resides**

  - Connect

  - Enter and send any characters in the edit window

    .. image:: ../../../../../samples/lwip/doc/lwip_tcpecho_1.png

  - Watch the characters echoed from MCU

    .. image:: ../../../../../samples/lwip/doc/lwip_tcpecho_2.png