Turning Ideas Into Reality

ABCircuits www.abcircuits.com POB 123 New Hill NC 27562 (919) 290-7104

Part Number KBDGRAY

Example Circuits

VCC

J1

DB9S

1

2

3

4

5

6

7

8

8

9

VCC

KBDGRAY

11

5

12

13

14

15

1

2

3

4

6

7

9

10

18

8

16

19

20

17

COLX2

NC

COLX1

SOUT

NC

NC

ROWY1

ROWY2

ROWY3

ROWY4

NC

NC

COLX3

VSS

NC

COLX4

NC

NC

VDD

NC

C6

.1

U2

SEE NOTES

1

3

4

5

2

6

11

14

10

7

12

13

9

8

C1+

C1-

C2+

C2-

V+

V-

T1in

T1out

T2in

T2out

R1out

R1in

R2out

R2in

U2= MAX232 FOR 5V RS232

+5

GND

PINS1X8

1

2

3

4

5

6

7

8

1

2

3

4

5

6

7

8

9

*

0

#

A

B

C

D

KEYPAD

1

2

3

4

RS232

C5

.1

U2= MAX3232 FOR 3V RS232

16 KEY RS-232 ENCODED KEYBOARD

C8

.1

TXD

C7

.1

1

2

3

4

5

6

7

8

9

*

0

#

KEYPAD

1

2

3

4

KBDGRAY

11

5

12

13

14

15

1

2

3

4

6

7

9

10

18

8

16

19

20

17

COLX2

NC

COLX1

SOUT

NC

NC

ROWY1

ROWY2

ROWY3

ROWY4

NC

NC

COLX3

VSS

NC

COLX4

NC

NC

VDD

NC

12 KEY RS-485 ENCODED KEYBOARD

VCC

VCC

U2

8

5

7

6

1

4

2

3

VCC

GND

-DO/-RI

DO / RI

RO

DI

-RE

DE

PINS1X7

1

2

3

4

5

6

7

U2 75176 FOR 5V

RS485 OUT

U2 MAX3485 FOR 3.3V

VCC