M I K R O E L E K T R O N I K A S O F T W A R E A N D H A R D W A R E S O L U T I O N S F O R T H E E M B E D D E D W O R L D
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5
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dsPICPRO
USB
3
dsPICPRO3 User
’
s Manual
MikroElektronika
Development tools
RR
SS
--44
88
55
CC
OO
MM
MM
UU
NN
IICC
AA
TT
IIOO
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RS-485 communication enables point-to-point and point-to-multipoint data transfer. It is
commonly used for data transfer between several microcontrollers. LTC485 interface tran-
ciever is used to transform signal from microcontroler’s Rx and Tx lines to differential sig-
nal on A and B output lines.
dsPICPRO3 development board has one RS485 communication device. In order to provide
more flexible system, microcontroller is connected to LTS485 through three switches on
SW4. These switches are used to connect Rt, Rx and Tx lines from microcontroller to RS485
port.
RS-485 COMMUNICATION
LTC485
B
DI
VCC
RE
DE
A
GND
RO
485-B
485-A
CN14
12
R16
10K
VCC
VCC
RT485
RX485
TX485
R38
4K7
R39
4K7
R41
56
R40
56
X1
10MHz
C1
22pF
C2
22pF
VCC
RG15
RC1
RC2
RC3
RC4
RG6
RG7
RG8
MCLR
RG9
Vss
Vdd
RA12
RA13
RB5
RB4
RB3
RB2
RB1
RB0
RC14
RC13
RD0
RD11
RD10
RD9
RD8
RA15
Vss
OSC2
OSC1/CLKI
Vdd
RG2
RG3
RF6
RF7
RF8
RF2
RF3
RB6 RB7
RA9
RA10 A
Vdd
A
Vss
RB8
RB9
RB1
1
Vss
Vdd RB12
RB13
RB14
RB15
RD14
RD15
RF4
RF5
RG13 RG12
RG14
RA7 RA6
RG0
RG1
RF1
Vdd
Vss
RD7 RD6
RD5
RD4
RD13
RD12
RD3
RD2
RD1
dsPIC30FXXXX
RF0
RB10
RA14
1
ON
4
3
2
58
7
6
SW4
RG8
RF4
RF5
RC13
RG7
RG6
RG2
RG3
MOSI
RX485
TX485
RT485
MISO
SCK
SCL
SDA
SUPPORTED
SUPPORTED
RS-485
RS-485
Figure 42.
RS485 Connector
Figure 43.
RS485Connector schematic
