MIKROE-415 mikroElektronika, MIKROE-415 Datasheet - Page 12

• Manufacturer Part Number: MIKROE-415
• Description: Development Boards & Kits - AVR EASYAVR6 DEVELOPMENT SYSTEM
• Manufacturer: mikroElektronika

Specifications of MIKROE-415

• Tool Type: AVR Development Board
• Interface Type: RS-232, USB, JTAG UART
• Dimensions: 265 mm x 220 mm
• Operating Supply Voltage: 9 V to 32 V
• Lead Free Status / Rohs Status: Details

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MikroElektronika
8.0. RS-232 Communication Interface
The USART (universal synchronous/asynchronous receiver/transmitter) is one of the most common ways of exchanging data
between the PC and peripheral components. RS-232 serial communication is performed through a 9-pin SUB-D connector and the
microcontroller USART module. In order to enable such communication, it is necessary to establish a connection between RX and TX
communication lines and microcontroller pins provided with USART module using a DIP switch SW9. The microcontroller pins used in
such communication are marked as follows: RX - receive data and TX - transmit data. Baud rate goes up to 115 kbps.
In order to enable the USART module of the microcontroller to receive input signals with different voltage levels, it is necessary to
provide a voltage level converter such as MAX202C.
The function of DIP switch SW9 is to determine which of the microcontroller pins are to be used as RX and TX lines. The microcontroller
pinout varies depending on the type of the microcontroller. Figure 8-2 shows the connection between the RS-232 module and the
microcontroller in DIP40 package (ATMEGA16).
Figure 8-2: RS-232 module schematic
NOTE:
SW9: RX=PB2, TX=PB3 = ON
Make sure that your microcontroller is provided with the USART module as it is not necessarily integrated in all AVR microcontrollers.
SUB-D 9p
Bottom view
9
5
RS232
1
6
RS-232 connector
C28
100nF
C30
100nF
C29
100nF
5
9
MAX202
C1+
V+
C1-
C2+
C2-
V-
T2 OUT
R2 IN
Figure 8-1: RS-232 module
R1 OUT
R2 OUT
T1 OUT
R1 IN
T1 IN
T2 IN
GND
VCC
6
1
VCC
C 1
100nF
3
VCC
RX
TX
R54
1K
SW9
PB2
PD0
PD2
PB3
PD1
PD3
VCC
EasyAVR6 Development System
EasyAVR6 Development System
DIP40
PB0
PB1
PB2
PB3
PB4
PB5
PB6
PB7
RESET
VCC
GND
XTAL2
XTAL1
PD0
PD1
PD2
PD3
PD4
PD5
PD6
AVCC
AREF
GND
PC7
PC6
PC5
PC4
PC3
PC2
PC0
PD7
PA0
PA2
PA3
PA4
PA5
PA6
PA7
PC1
PA1
VCC