Simple PICmicro Clock

Myke Predko

2000.02.29

1
2

J1

HDR_2

C1

10 uF

C2

10 uF

1

IN

2

GND

3
OUT

U1

7805

1

RA2

2

RA3

3

RA4

4

_MCLR

5

Gnd

6

RB0

7

RB1

8

RB2

9

RB3

10

RB4

11

RB5

12

RB6

13

RB7

14

Vcc

15

OSC2

16

OSC1

17

RA0

18

RA1

U2

16LF84

23

A

22

B

21

C

20

D

18

G1

19

G2

1

0

2

1

3

2

4

3

5

4

6

5

7

6

8

7

9

8

10

9

11

10

13

11

14

12

15

13

16

14

17

15

U3

74LS154

23

A

22

B

21

C

20

D

18

G1

19

G2

1

0

2

1

3

2

4

3

5

4

6

5

7

6

8

7

9

8

10

9

11

10

13

11

14

12

15

13

16

14

17

15

U4

74LS154

23

A

22

B

21

C

20

D

18

G1

19

G2

1

0

2

1

3

2

4

3

5

4

6

5

7

6

8

7

9

8

10

9

11

10

13

11

14

12

15

13

16

14

17

15

U5

74LS154

23

A

22

B

21

C

20

D

18

G1

19

G2

1

0

2

1

3

2

4

3

5

4

6

5

7

6

8

7

9

8

10

9

11

10

13

11

14

12

15

13

16

14

17

15

U6

74LS154

23

A

22

B

21

C

20

D

18

G1

19

G2

1

0

2

1

3

2

4

3

5

4

6

5

7

6

8

7

9

8

10

9

11

10

13

11

14

12

15

13

16

14

17

15

U7

74LS154

X1

32 KHz

C3

0.1 uF

C4

0.1 uF

C5

0.1 uF

C6

0.1 uF

C7

0.1 uF

C8

0.1 uF

C9

27 pF

C11

27 pF

1

2

SW1

SW_SPST

R1

10K

.25W

R2

10K

.25W

C

A

D1

C

A

D2

R3

220 .25W

R4

220 .25W

Vcc

Hour '154

Minutes 0 - 15 '154

Minutes 16 - 31 '154

Minutes 32 - 47 '154

Minutes 48 - 59 '155

GND

GND

GND

GND

GND

GND

GND

GND

GND

GND

GND

GND

GND

GND

C

A

CR2

1N914

C

A

CR14

1N914

Vcc

PIC

PIC

Vcc

GND

Vcc

Battery

Place C4 - C8 Close to U3 - U7's Vcc

M0
M1
M2
M3

S0

S1

S2

S3

H0

H1

H2
H3

M0
M1
M2
M3

M0
M1
M2
M3

M0
M1
M2
M3

M0
M1
M2
M3

S0

S1

S2

S3

H0
H1
H2
H3

Power Backup Battery, 2.8 Volt
Lithium PC Battery

LED Circuit is repeated for all '154 Outputs
16 LEDs for Minutes 0 through 47
12 LEDs for Minutes 48 through 59
12 LEDs for Hours

PIC