Senior Design Project 2001
An Internet Interface for Embedded Systems
by Arun Gupta and Phillip Hoang

Click Picture for a Demonstration


The goal of this design project is to create a device that will enable other devices to communicate over the Internet. This is accomplished by putting together a network such that it is low cost, small in size, and does not consume too much processor resources. In addition for it to be marketable, it must conform to current protocols and standards.  The design chosen for this project is a User Datagram Protocol over the Internet Protocol over Ethernet (UDP/IP/Ethernet) implementation on an Intel 8051 microcontroller.


The device created in this project is the Internet Interface, as can be seen from the diagram below.  For demonstration purposes, a temperature sensor device is added; and on the receiving end of the data, there is a listener program that generates web pages on a web-server.  The temperature sensor, LCD, and Internet Interface is implemented on a single board.  The board is current connected in Bourn B256, and the listener program is ran in a /.html directory on hill (the CS department's main server).  The temperature sensor send the temperature to the Internet Interface.  The Internet Interface is connected through Ethernet on a local area network.  It creates UDP packets and sends it across the Internet.  The destination for the packet is the web server, and on the web server is a listener program.  The program receives the UDP packet and puts the temperature data onto a web page.  The demonstration shows that a device (i.e. a temperature sensor) can communicate over the Internet, and it can be monitored remotely.


The Intel 8051 Microcontroller

The Intel 8051 is a single-chip microcontroller. It is commonly used in embedded systems due to its small size, flexibility and low power consumption. The main drive for the development of this product was to be able to be embedded directly into commercial products is reduced cost.

Some of its pertinent features are:

In this project, the Intel 8051 microcontroller will be used to implement the UDP/IP stack.

The Embedded Ethernet Card

The embedded Ethernet board utilizes the Crystal LAN 8900A chip produced by Cirrus Logic. This chip is a low-cost Ethernet LAN controller optimized for Industry Standard Architecture (ISA) Personal Computers. Its highly integrated design eliminates the need for costly external components required by other Ethernet controllers. The CS8900A includes on-chip RAM, 10BASE-T transmit and receive filters, and a direct ISA-bus interface.  In the design of the embedded Ethernet board, only four address lines are used instead of the usual sixteen for an ISA bus.This is because the embedded Ethernet board is the only device connected to the bus. Twelve of the address lines are hardwired to the base address of the embedded Ethernet board.

The Crystal 8900A chip is used in 8-bit mode for this implementation. More extensive information about the chip can be found in the technical manual.

The embedded Ethernet board is from

Hardware Schematics

Software Overview


This page last updated June 15, 2001