An 8051 Based Web Server

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An 8051 Based Web Server

• Project by Mason Kidd
• Advised by Dr. Schertz

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Outline

• Abstract
• Overview of TCP/IP and HTTP
• Functional Description
• Block Diagram and Software Flow Chart
• Datasheet
• Hardware Description
• Completed Lab Work
• Problems Encountered
• Future Work/Applications

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Abstract

• A web server was designed using an 8051 based
  micro controller. The micro controller was
  interfaced to an Ethernet network using an
  Ethernet transceiver chip. This allows the user
  to connect to the micro controller using a
  standard web browser and receive data in the form
  of a web page.

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Overview of TCP/IP and HTTP

• TCP/IP is the protocol used over the Internet to
  allow communication between computers
• It is a layered protocol based on Open Systems
  Interconnection

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Overview of TCP/IP and HTTP

• Each layer adds a header to the data
• Process is called encapsulation
• My software must create and decode these headers

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Overview of TCP/IP and HTTP

• Ethernet - network type, determines cable type,
  connector type, hardware (MAC) address
• IP - Internet Protocol, defines network addressing

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Overview of TCP/IP and HTTP

• ICMP - Internet Control Message Protocol, allows
  for testing of connectivity
• ARP - Address Resolution Protocol, used to
  retrieve Ethernet address for a certain IP
  address
• UDP - User Datagram Protocol, connectionless data
  transfer protocol
• TCP - Transmission Control Protocol,
  connection-based reliable data transfer protocol

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Overview of TCP/IP and HTTP

• Hypertext Transport Protocol is the protocol used
  by web browsers to communicate with web servers
• Web browser asks the web server for a document,
  and the web server sends the document back
• Hypertext Markup Language is the type of document
  used, uses tags to format data

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Functional Description

• I/O are packets to the Ethernet network and
  information/control signals to microcontroller
  interfaces
• Operates in two modes Listening and Responding
• Packet types supported Internet Control Message
  Protocol, Address Resolution Protocol,
  Transmission Control Protocol, and User Datagram
  Protocol

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Block Diagram
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Block Diagram
Subsystem Inputs Outputs
Microcontroller Interfaces Control signals Acquired data
EMAC Microcontroller Acquired data, Packets Control signals, Packets
Ethernet Interface Packets Packets
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Software Flow Chart
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Datasheet

• Description
• A micro webserver based on an 8051 development
  board. Serves small web pages with information
  collected from on-board peripherals.
• Quantitative Specifications
• Maximum Packet Size 1500 bytes
• Number of Simultaneous Connections 1
• Protocols Supported IP, ARP, ICMP, TCP, UDP,
  HTTP/1.0, HTML/2.0
• Network Interface Type 10BaseT Ethernet
• User Interface
• Users connect to the system using a standard web
  browser.
• System Testing
• System can be tested for network connectivity by
  'pinging' the system. Also, Link and Activity
  LEDs are available on the system to provide
  network link and activity status.

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Hardware Description

• Uses a Crystal CS8900A Ethernet Transceiver
• Designed for use with ISA bus systems
• Has internal memory for storage of packets
• Application note describes using in 8-bit mode
• Connected to an EMAC board using the bus
  expansion header
• Very little glue logic needed
• Constructed using wire-wrap

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Completed Lab Work

• Wrote low level interface software
• Wrote software to receive packet and determine
  what type it is
• Wrote software to process ICMP, ARP, UDP, and TCP
  packets
• Wrote UNIX sockets client program for testing of
  UDP functionality
• Wrote web server software to process HTTP packets
  and construct HTML pages
• Constructed and tested hardware

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Problems Encountered

• Cannot read received packet from Ethernet
  Transceiver chip
• Used packet sniffer program to place packet into
  buffer
• Software processed packets correctly

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Future Work/Applications

• Need to resolve packet reception problem
• Expand code to be usable with other micro
  controllers
• Make TCP/IP stack more robust, support more of
  the options defined in standards
• Expand HTTP server to allow POST methods and CGI
  processing
• Industrial applications - monitor machinery,
  remote control
• Robotics applications - replace laptops used for
  remote control