Datasheet

15
Easy24-33 v6 Development System
MikroElektronika
page
11.0. RS-232 Communication Module
The Easy24-33 v6 development system features the RS-232 module that serves as an interface between the microcontroller and
an external device using RS-232 communication to exchange data. The RS-232 module is connected to that device through a 9-pin
SUB-D connector. For communication with the microcontroller, this module uses TX pin for sending and RX pin for receiving data. For
the microcontroller to be capable of exchanging data with the RS-2323 module, it is necessary to be provided with a built-in USART
module. Connection between the RS-232 module and the microcontroller is established by setting the appropriate switches on the DIP
switch SW1 to the ON position. The RS-232 module’s TX pin can be connected to the microcontroller via either RB14, RB7 or RB0
microcontroller pin, whereas the RX pin can use either RB14, RB7 or RB0 microcontroller pin for such connection. In the example in
Figure 11-2, the microcontroller is connected to the RS-232 module via RB15 and RB14 pins.
In order to enable 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 MAX3232 (MAX232).
Figure 11-2: RS-232 module and microcontroller connection schematic
127( Make sure that your microcontroller is provided with the USART module as it is not necessarily integrated in all PIC24
microcontrollers.
The function of switches 1-6 on the DIP switch SW1 is to determine which microcontroller pins are to be used as RX and TX lines.
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Figure 11-1: RS-232 module
Port RS-232 is connected to the microcontroller
RS-232 connector