1 2 3 4 5 6
A
B
C
D
654321
D
C
B
A
P1.0
1
P1.1
2
P1.2
3
P1.3
4
P1.4
5
P1.5
6
P1.6
7
P1.7
8
RST
9
P3.0(RXD)
10
P3.1(TXD)
11
P3.2(INT0)
12
P3.3(INT1)
13
P3.4(T0)
14
P3.5(T1)
15
P3.6(WR)
16
P3.7(RD)
17
XTAL2
18
XTAL1
19
GND
20
(A8)P2.0
21
(A9)P2.1
22
(A10)P2.2
23
(A11)P2.3
24
(A12)P2.4
25
(A13)P2.5
26
(A14)P2.6
27
(A15)P2.7
28
PSEN
29
ALE/PROG
30
EA/VPP
31
(AD7)P0.7
32
(AD6)P0.6
33
(AD5)P0.5
34
(AD4)P0.4
35
(AD3)P0.3
36
(AD2)P0.2
37
(AD1)P0.1
38
(AD0)P0.0
39
VCC
40
U1
89C52/S52
3
2 1
P1
POWER
VCC
1
1
2
2
3
3
4
4
5
5
6
6
S1
SWITCH
b
ce
Q1
9012
Y1
12MHz
C3
30
C4
30
1 2
3 4
K4
seeNL-NZ
R4
10K
VCC
VCC
b
c e
Q2
9012
VCC
R2
2.2K
LS1
SPEAKER
GND
1
VCC
2
V0
3
RS
4
R/W
5
EN
6
D0
7
D1
8
D2
9
D3
10
D4
11
D5
12
D6
13
D7
14
A
15
K
16
D2
LCD_1602VCC
VCC
1 2
3 4
K1
SET
1 2
3 4
K2
UP
1 2
3 4
K3
DOWN
R3
2.2K
COM
1
R1
2
R2
3
R3
4
R4
5
R5
6
R6
7
R7
8
R8
9
103
10K
VCC
VCC
Vcc2
1
X1
2
X2
3
GND
4
CE
5
I/O
6
SCLK
7
Vcc1
8
U2
DS1302
P2
3V
Y2
32.768
+
C1
10uF
GND
1
DQ
2
VCC
3
U3
DS18B20
R5
10K
VCC
VCC
R6
10K
R7
1K
R8
10K
R9
10K
R10
10K
VCC