The USB LCD Panel

1
The USB LCD Panel

• Doug Bennett
• Cody Garvin

2
Discussion Outline

• Overview
• Flowchart
• Hardware
• USB Interface
• LCD Panel
• Project Schematic
• LCD Interface Functions
• User Application
• Project Demonstration Photos
• Schedule

3
Project Overview

• Develop a method to interface an LCD to a Windows
  XP PC through USB
• Develop a library of functions that can be used
  to display text to the LCD
• Develop a user application that will allow users
  to display text to the display

4
Project Flowchart
5
The USB Interface

• DevaSys USBI2CI/O Interface Board
• Provided USB interface to PC
• Enough digital I/O pins to control LCD panel
• Provided API for use with software applications

6
The LCD Panel

• Emerging Displays EW20400GLY
• 4 line by 20 character display
• Different From Original Display
• Original display would not work with 3.3V logic
  levels

7
Schematic
8
Prototype
9
LCD Interface Functions

• Basic Interface Functions Developed In C
• Quick implementation to test display and project
  circuits
• Easy integration with provided API for testing of
  functions
• Easy to port to C
• Various Functions Developed
• Include ability to scroll text, write one screen
  at a time, turn cursor on/off, turn blink on/off,
  and clear display

10
The User Application

• Developed In C Using MFC
• Allowed for quick production of Windows user
  interface
• Several Options Available for User
• Can enter text, open a text file, or enter ticker
  symbols to display on the LCD panel

11
Project in Action

• Left Screen Shows Entering a File to Scroll
• Press text file radio button, and open file
  dialog opens
• Right Screen Shows Entering Ticker Symbols
• Application accesses Yahoo site to retrieve
  information

12
Project in Actioncontinued

• Both Screens Display Scrolling Text
• Left screen is from text entered into box
• Right screen is from a text file

13
Schedule

• Proposed Gantt Chart

• Actual Gantt Chart
• Started slightly later
• Had a few setbacks with LCD panel, but still
  completed on time