1. Homework Assignment 3 Due date: Tuesday, Wednesday, or Thursday, October 4-6, 2005 input: push-button switch output: seven-segment LED 7 points Menu System

2. Specification: One or two seven segment displays should be used to display menu title and menu items sequentially, character by character. The best effort should be made to display as many letters as possible, as accurately as possible. Output: Input: A single button switch should be used to select menu options. 1-3 presses of the button = appropriate item of the menu 4 presses of the button = “UP” 5 presses of the button = “HOME”

3. Requirements: 1.Input key debouncing should be done in software 2.Interface should be as readable and user-friendly as possible 3.The program should be written in such a way that a change of a single constant, followed by rebuilding and downloading the program should be sufficient to change an input or output device.

4. Suggested Program Structure menu_desc.c menu.h description of the menu system application dependent type definitions, application independent menu_ctrl.c function(s) controlling the operation of the menus io.h independent of input/output devices application contents of the menus low-level input/output functions dependent on input/output devices main.cmain program, application dependent io.c i/o function declarations, i/o dependent

5. Deliverables 1.Electronic version of the detailed chart describing menu system 2.Detailed schematic of the circuit with component numbers and values of discrete components 3.Full source code of your program 4. Demo of the correctly operating system

6. Required Reading Spasov, Microcontroller Technology: The 68HC11 Chapter 9.2 Seven Segment (LED) Display Output Chapter 11.1 Timer Overview Chapter 11.2 Output Compare Chapter 8 Interfacing Concepts