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