This document describes an EOS project for a Morse code chatroom. It includes an architecture that uses functions like accept(), connect(), setname(), and reply() to set up client-server connections. It also describes the client-server activities like changing names and sending/receiving messages. Finally, it details the input/output design using a keypad and LCD for interaction and includes diagrams of the interfaces. It proposes using asymmetric encryption and select() for monitoring to optimize memory usage and improve real-time performance of the chatroom.

1. EOS Project
Morse code chatroom
Teacher : 黃育綸 教授
Student : 0460028楊偉晨、0460003陳奕升、0450728林鈺玲

2. Architecture
accept()connect()
setname()
reply()
request()
OK
reply()
TIME?
Ready TIME
NAME
Connection Set Up

3. Ready
Client-Server Actitvities
Ready
Ready Ready
change name
OK
Ready
Client A
Client B
Client DClient C
send
{msg to B)
receive
(msg from A)
Who's online?
Who's online?
A B C D
(id,ip,name )

4. Select
(wait until
something
happen)
fd(keypad)sockfd
write in to file
(store msg)
instant news
update
(on LCD)
show LCD
Mainmenu
based on mode
Display online
people
change name
chat with someone
EXIT
Client Routine

5. I/O Design - Keypad
ABC
abc
DEF
def
GHI
ghi
Input
type
JKL
jkl
MNO
mno
P Q R
pqr 上捲
STU
stu
VWX
vwx
YZ＿
yz＿ 下捲
Leave
Room
, . =
! ? *
Back
space
Send
1 2 3
4 5 6
7 8 9
0
Use timer interrupt
to trigger if the
keypad is changing
character (and clock)
Press this button
to change the
input type

6. I/O Design - LCD
GHI
ghi
Input
type
P Q R
pqr 上捲
YZ＿
yz＿ 下捲
Back
space
Send
3
6
9
Conversation
Instant News
Page bar | Input type
Scrolling Text

7. Asymmetric Encryption

8. In morse code chatroom

9. SCAMPER
• 合併(C):
• 原有的Keypad僅有16個鍵，透過與Timer signal的合併，可以鍵入完整的大小寫英
文、數字以及符號(因PXA270不支援其他語系的編碼)。
• 微調(A):
• 透過摩斯密碼加密送出談話內容，再加上Public Key和Private Key的加密解密，可
以防止他人的竊聽。
• 修改(M):
• 由於Multi-thread會佔用較多的記憶體空間，且相比起來即時性較低，透過select的
監聽可以優化上述的缺陷。

10. Thank you 