Datasheet
UART via RS-232
The UART (universal asynchronous receiver/
transmitter) is one of the most common ways of
exchanging data between the MCU and peripheral
components. It is a serial protocol with separate
transmit and receive lines, and can be used for full-
duplex communication. Both sides must be initialized
with the same baudrate, otherwise the data will not be
received correctly.
RS-232 serial communication is performed through a 9-pin
SUB-D connector and the microcontroller UART module. In
order to enable this communication, it is necessary
to establish a connection between RX and TX
lines on SUB-D connector and the same pins on
the target microcontroller using DIP switches.
Since RS-232 communication voltage levels
are dierent than microcontroller logic
levels, it is necessary to use a RS-
232 Transceiver circuit, such as
MAX3232 as shown on
Figure 8-1.
DATA BUS
Figure 8-1: RS-232 connection schematics
Enabling RS-232
In order to enable RS-232
communication, you must push
SW5.3 (RG1) and SW5.4 (RG2)
to ON position. This connects the
RX and TX lines to appropriate
microcontroller pins and its second
UART module.
communication
page 22
EasyPIC PRO
v7