1.5 Berkeley UDP Server

Description

The Berkeley UDP 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 - Berkeley UDP Server

The following Project Graph shows the Harmony components included in the Berkeley UDP Server demo application.

TCP/IP Configuration - Berkeley UDP 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

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.
- Berkeley API provides the Berkeley_Socket_Distribution (BSD) wrapper to the native Harmony TCP/IP Stack APIs
- Announce to discover the Microchip devices within a local network.

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\berkeley_udp_server\firmware .

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

Table 1-6. Demo Configurations
Project Name	Target Device	Development Board	Description
sam_9x75_ddr3_eb.X	SAM9X75	SAM9X75-DDR3-EB	Berkeley UDP Server - Bare Metal
sam_9x75_ddr3_eb_freertos.X	SAM9X75	SAM9X75-DDR3-EB	Berkeley UDP 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.

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

Open a terminal application on the host computer (like Hyper-terminal or Tera Term).
Configure the terminal application for serial port connected to DBGU1 port.
Set baud rate as 115200 in the terminal application.
Build and download the application project on the target board.
Ensure connection from Gigabit(1000Mbps) capable network socket of a router/switch/computer to the board.
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 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.

Send a UDP packet to the IP address of the hardware board, port 9760, from UDP Client application (PacketSender) running on the computer. See the following screenshot.
The UDP Server running on the hardware board will echo back the message it receives. See the following Console screenshot.