Mikroelektronika MIKROE-742 데이터 시트

340

- SOFTWARE AND HARDWARE SOLUTIONS FOR EMBEDDED WORLD

CHAPTER 6

procedure RS485Master_Init();

Nothing.

Initializes MCU as a Master for RS-485 communication.

Global variables : 

- 

RS485_rxtx_pin

- this pin is connected to RE/DE input of RS-485 

transceiver(see schematic at the bottom of this page). RE/DE signal controls 
RS-485 transceiver operation mode.

- 

RS485_rxtx_pin_direction

- direction of the RS-485 Transmit/Receive pin 

must be defined before using this function. 

UART HW module needs to be initialized. See UARTx_Init.

// RS485 module pinout
var RS485_rxtx_pin : sbit  at PORTD.B2;         
var RS485_rxtx_pin_direction : sbit  at DDRD.B2;
// End of RS485 module pinout

// Pass pointers to UART functions of used UART module

UART_Wr_Ptr := @UART1_Write;

UART_Rd_Ptr := @UART1_Read;
UART_Rdy_Ptr := @UART1_Data_Ready;

UART_TX_Idle_Ptr := @UART1_TX_Idle;
...

UART1_Init(9600);                    // initialize UART module

RS485Master_Init();                  // intialize MCU as a
Master for RS-485 communication