EasyPIC4 User
’
s Manual
2
26
6
page
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
MikroElektronika
Development
tools
EasyPIC
ICD
4
RR
SS
--22
33
22
CC
OO
MM
MM
UU
NN
IICC
AA
TT
IIOO
NN
RS-232 communication enables point-to-point data transfer. It is commonly used in
data acquisition applications for the transfer of data between microcontroller and a
PC. Since the voltage levels of a microcontroller and PC are not directly compati-
ble with those of RS-232, a level transition buffer, such as the MAX232, must be
used. In order to provide a more flexible system, the microcontroller is connected
to the MAX232 through the two jumper
groups: JP7 and JP8. The jumper group JP7
is used to connect the Rx line to RC7, RB2 or
RB1. The jumper group JP8 is used to connect
the Tx line to RC6, RB5 or RB2. Note that
JP7 and JP8 must not be connected to RB2 at
the same time. JP6 enables the connections of
RB0 pin to CTS and RC2 pin to RTS line for
implementing hardware handshaking.
RS-232 COMMUNICATION
VCC
VCC
1
1
6
6
9
9
5
5
C1+
VCC
V+
GND
C1-
T1out
C2+
R1in
C2-
R1out
V-
T1in
T2out
T2in
R2in
R2out
MAX232
Serial Cable
Rx
Tx
Tx
Rx
RC6
RB5
RB2
RC2
RTS
RB2
RC7
RB1
RB0
CTS
E9
10uF
E8
10uF
E10
10uF
E11
10uF
PICxxxx
RA0
RA1
RA2
RA3
RC0
RC1
RA4
RA5
RE0
RE1
RE2
RC3
RD0
RD1
RC4
RD3
RD2
RC5
RC6
RC7
RD4
RD5
RD6
RD7
RB0
RB1
RB2
RB3
RB4
RB5
RB7
RB6
RC2
VDD
VSS
OSC1
OSC2
MCLR
VDD
VSS
X1
8MHz
C6
22pF
C7
22pF
RTS
CTS
JP8
JP7
JP6
Figure 35.
Figure 36.
Connection between
microcontroller
and a PC
RS232 connector
