The Practice of Micro-processor

Yonam Institute of Digital Technology

05. Key Matrix Control

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Key Matrix We have variant way to insert key information in digital

circuit. For the way, we usually use Key Matrix. Because it is a way which can get many key information

by using small number of ports.

4X4 Key Matrix uses 4 for out port uses 4 for in port

Overview of Key MatrixOverview of Key Matrix

Key Data Input / Output

Overview of Key MatrixOverview of Key Matrix

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스위치를 누르면연결된다.

0xfe 하위 1110

출력

1011입력

받는다.

받는 값 : Key 인식

1110 : C

1101 : 8

1011 : 4

0111 : 0

Test-Board contains 4x4 Key Matrix

Key Matrix in Test BoardKey Matrix in Test Board

4

  

  

Port Specify

PC.0~3 insert signal to choice a line of Key Matrix (Output)

PC.4~7 receive choose key value of Key Matrix (Input)

Circuit Diagram for Key Matrix Circuit Diagram for Key Matrix ControlControl

e(1110)

d(1101)

b(1011)

7(0111)

Arrangement of Key Matrix Components

Key Matrix

Data Bus Jumper

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PC.0 ●

PC.1 ●

PC.2 ●

PC.3 ●

PC.4 ●

PC.5 ●

PC.6 ●

PC.7 ●

● C.0

● C.1

● C.2

● C.3

● L.0

● L.1

● L.2

● L.3

8583PC PORT

Key MatrixPart

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Wiring Diagram

  

AVR8535MCU Module

Multi DigitalBreadboard

PA.0 ●

PA.1 ●

PA.2 ●

PA.3 ●

PA.4 ●

PA.5 ●

PA.6 ●

PA.7 ●

● Q.0

● Q.1

● Q.2

● Q.3

● A

● B

● C

● D

● E

● F

● G

● P

PB.0 ●

PB.1 ●

PB.2 ●

PB.3 ●

PB.4 ●

PB.5 ●

PB.6 ●

PB.7 ●

8583PA PORT

8583PB PORT

7-SegmentPart

7-SegmentPart

PC.0 ●

PC.1 ●

PC.2 ●

PC.3 ●

PC.4 ●

PC.5 ●

PC.6 ●

PC.7 ●

● C.0

● C.1

● C.2

● C.3

● L.0

● L.1

● L.2

● L.3

8583PC PORT

Key MatrixPart

Practice of Key Matrix ControlPractice of Key Matrix Control

key Matrix 에서 ‘ 4’ 에 해당하는  Key 가 눌려지면  7-Segment 로 ‘ 4’ 를 출력  ( 단 , ‘4’ 가 아닌 다른  key 가 눌려지면  FND 는 변동사항 없음 )

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C D E F

8 9 A B

4 5 6 7

0 1 2 3

C D E F

8 9 A B

4 5 6 7

0 1 2 3

  

  

key Matrix 에서 ‘ 1’ 에 해당하는  Key 가 눌려지면  7-Segment 로 ‘ 1’ 을 출력  ( 단 , ‘1’ 이 아닌 다른  key 가 눌려지면  FND 는 변동사항 없음 )

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C D E F

8 9 A B

4 5 6 7

0 1 2 3

C D E F

8 9 A B

4 5 6 7

0 1 2 3

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Key Matrix 의  Key 값을 읽어서  7-Segment 로 출력

C D E F

8 9 A B

4 5 6 7

0 1 2 3

C D E F

8 9 A B

4 5 6 7

0 1 2 3

C D E F

8 9 A B

4 5 6 7

0 1 2 3

C D E F

8 9 A B

4 5 6 7

0 1 2 3…

Advanced PracticeAdvanced Practice

Key Matrix 를 사용하여  Password 를 입력하는 전자 자물쇠 구현 Password 저장  mode ( 초기값 “ 0000” 이다 )

Password 입력  mode

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(MSB) (LSB)

(MSB) (LSB)

C D E F

8 9 A B

4 5 6 7

0 1 2 3

C D E F

8 9 A B

4 5 6 7

0 1 2 3

Password 입력이 맞으면

Password 입력이 틀리면

반복

▲ 7-Segment Part ▲ Digital I/O Part