4
4-PIN RS-485 HEADER
3
2
1
C8
2200uF@25VDC
+
5V0
C3
100nF
D+
D-
V_MOTOR
5
8
GND
MAX485
VCC
DI/RO
7
6
DI/RO
U2
RO
RE
DE
2
3
4
DI
1
5V0
MODE_SW
10K
R4
TX
RX
8
GND
19
GND
PIC18F2620
2
RA0
3
RA1
4
RA2
5 27
RC6/TX
18
RC5
17
RC4
16
RC3
15
RC2/CCP1
14
RC1/CCP2
13
RC0
12
RB5
11
RB4
26
RB3
25
RB2
24
RB1
23
RA5
10
RB0/INT0
22
RA7
21
RA3 RB6/PGC
6 28
RA6
9
7
RA4/T0CKI RB7/PGD
RC7/RX
U1
5V0
20
VDD
1
MCLR
C2
100nF
6
6
5
5
4
4
ICSP CONNECTOR
2
2
1
1
3
3
R2 1K
R1
100
5V0
R3
10K
C1
100nF
SCHEMATIC 2. The 74HC125 and
CD4069 are replaced by the MAX485
RS-485 transceiver. Otherwise, the
song remains the same. Note that
you’ll have to provide a suitable power
source for V_MOTOR.
J1
POWER
C4
470uF
+
9V6
1
IN
C5
100nF
VR1
LM340S- 5.0
3
GND
2
OUT
C6
100nF
C7
470uF
+
5V0
SERVO 05.2009
39
