Datasheet

14
BIG AVR 6 Development System
MikroElektronika
page
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USART (8QLYHUVDO6\QFKURQRXV$V\QFKURQRXV5HFHLYHU7UDQVPLWWHU) is one of the most common ways of exchanging data between
the PC and peripheral units. RS-232 serial communication is performed through a 9-pin SUB-D connector and the microcontroller
USART module. The BIGAVR6 provides two RS-232 ports, RS-232A and RS-232B. Use switches marked as RX232-A (PE0 pin) and
TX232-A (PE1 pin) on the DIP switch SW13 to enable port RS-232A. Likewise, use switches marked as RX232-B (PD2 pin) and TX232-
B (PD3 pin) on the DIP switch SW13 to enable port RS-232B. The microcontroller pins used in such communication are marked as
follows: RX - UHFHLYHGDWDOLQH and TX -WUDQVPLWGDWDOLQH. Data rate goes up to 115 kbps.
In order to enable the USART module of the microcontroller to receive input signals which meet the RS-232 standard, it is necessary
to adjust voltage levels using an IC circuit such as MAX202.
)LJXUH: RS-232 module connection schematic
The function of the switches 5-8 on the DIP switch SW13 is to determine which of the microcontroller pins are to be used as RX and
TX lines, Figure 10-2.
)LJXUH: RS-232 module
RS-232 connector
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