RR
SS
--22
33
22
CC
OO
MM
MM
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IICC
AA
TT
IIOO
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DD
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LL
EE
RS-232 COMMUNICATION MODULE
RS-232 communication module enables point-to-point data trans-
fer. It is commonly used in data acquisition applications to transfer
data between the microcontroller and PC. Since the voltage levels
of the microcontroller and PC are not directly compatible with each
other, a level converter, such as MAX232, must be used. In order
to provide more flexible system, the microcontroller is connected to
the MAX232 via the DIP switches SW7 and SW8. The DIP switch
SW7 is used to connect Rx line to RC7, RB2, RB1, RB4, RA3 or
RB5. The DIP switch SW8 is used to connect Tx line to RC6, RB5,
RB2, RB1, RA2 or RB7. Note that pin RB2 must not be simultane-
ously connected to Rx and Tx line. If you want to implement hard-
ware handshaking, it is necessary to connect the RB0 pin to CTS
line and the RC2 pin to RTS line using the DIP switch SW7.
2
26
6
Figure 34
Figure 35
Connection between microcontroller and PC
RS-232 module