1.12 TCP/IP UDP Client Server

This demonstration is a combination of the UDP Client and UDP Server application.

It shows the usage of MPLAB Harmony UDP API to implement,

  • a UDP echo server on port 9760.
  • a UDP client that establishes TCP/IP connection to a UDP server, on port 9760

Description

The TCP/IP UDP Client Server application is based on MPLAB® Harmony 3 TCP/IP Stack.

The Harmony TCP/IP stack is a collection of different network protocols.

The source files of Harmony 3 TCP/IP stack is available here.

The demo is created with MPLAB X IDE and MCC plugin.

MCC Project Graph - TCP/IP UDP Client Server

The following Project Graph shows the Harmony components included in the TCP/IP UDP Client Server demo application.

Figure 1-40. Project Graph

FreeRTOS component is required for RTOS application. For bare-metal (non-RTOS) FreeRTOS component should not be selected.

TCP/IP Configuration - TCP/IP UDP Client Server

The TCP/IP modules enabled for the demo is shown in the TCP/IP Configuration Overview

More details of TCP/IP Configuration plugin is available here

Figure 1-41. TCP/IP Configuration

The Application Layer modules enabled in the demo are as follows:

  • Application Layer Modules
    • DHCP Client to discover the IPv4 address from the nearest DHCP Server.
    • DNS Client provides DNS resolution capabilities to the stack.

The Ethernet interface in this demo use internal GMAC peripheral and Gigabit Ethernet PHY Transceiver KSZ9131.

Downloading and Building the application

To clone or download this application from Github, go to the main page of this repository and then click Clone button to clone this repository or download as zip file.

This content can also be downloaded using content manager by following these instructions.

Path of the application within the repository is apps\tcpip_udp_client_server\firmware .

To build the application, refer to the following list of demo configurations and open the project using MPLAB X IDE.

Table 1-13. Demo Configurations
Project NameTarget DeviceDevelopment BoardDescription
sam_9x75_ddr3_eb.XSAM9X75SAM9X75-DDR3-EBTCP/IP UDP Client Server - Bare Metal
sam_9x75_ddr3_eb_freertos.XSAM9X75SAM9X75-DDR3-EBTCP/IP UDP Client Server - FreeRTOS

Hardware Setup - SAM9X75-DDR3-EB

The target board for running the application is SAM9X75-DDR3-EB.

This section provides essential hardware configuration of this target board to run TCP/IP applications.

Figure 1-42. SAM9X75-DDR3-EB

Board Setup

  • Default jumper setting of the board is a shown above.
  • Connect USB cable between USB-A port (J28) and host PC. This will supply 5V power to board.
  • Connect serial cable (FTDI) for debug console output on DBGU1(J36) port.
  • Connect Ethernet cable between RJ45 socket (J18) and router/switch/computer.

Setting up at91bootstrap loader

To load the application binary onto the target device, we need to use at91bootstrap loader.

Refer to the at91bootstrap loader documentation for details on how to configure and run/debug the application using MPLABX and booting application using an SD Card.

Running the Application

  1. Open a terminal application on the host computer (like Hyper-terminal or Tera Term).
  2. Configure the terminal application for serial port connected to DBGU1 port.
  3. Set baud rate as 115200 in the terminal application.
  4. Build and download the application project on the target board.
  5. Ensure connection from Gigabit(1000Mbps) capable network socket of a router/switch/computer to the board.
  6. Verify the TCP/IP Stack initialization console messages.

If DHCP client is enabled in the demonstration, wait for the DHCP server to assign an IP address for the development board.

This will be printed on the console. Otherwise, the default static IP address will be assigned to the board.

UDP Client Test

For UDP Client test, a UDP Server application is required to run on the host computer.

In this demonstration, we use PacketSender utility configured as UDP server.

Application commands for this demo are : setopt, getopt and sendudp.

  • setopt : Set the UDP packet options like destination IP address, destination port and message to send
  • getopt : Readback the current settings
  • sendudp : Send the UDP packet

UDP Server Test

For UDP Server test, a UDP Client application is required to run on the host computer (SocketTest, PacketSender etc).

In this demonstration, we use PacketSender utility as UDP Client.

  • Send a UDP packet to the IP address of the hardware board, port 9760, from UDP Client application (PacketSender) running on the computer.
  • The UDP Server running on the hardware board will echo back the message it receives.
Following screenshots show both UDP Client and UDP Server functions.
  • UDP Client PacketSender send message to UDP Server on board. Then UDP Server echoes it.
  • UDP Client on board send message to UDP server running on PacketSender
Packet Sender
Console Message