單片機RS485源程序如下:
- /********************************************************************
- 匯誠科技
- 實現功能:此版配套測試程序
- 使用芯片：STC11F104E
- 晶振：11.0592MHZ
- 波特率：9600
- 編譯環境：Keil
- 作者：zhangxinchunleo
- /********************************************************************
- 上電后，發送數據 STC10/11xx\r\nUart Test !\r\n
- ********************************************************************/
- #include "reg51.h"
- #include "intrins.h"
- typedef unsigned char BYTE;
- typedef unsigned int WORD;
- #define FOSC 11059200L //System frequency
- #define BAUD 9600 //UART baudrate
- /*Define UART parity mode*/
- #define NONE_PARITY 0 //None parity
- #define ODD_PARITY 1 //Odd parity
- #define EVEN_PARITY 2 //Even parity
- #define MARK_PARITY 3 //Mark parity
- #define SPACE_PARITY 4 //Space parity
- #define PARITYBIT EVEN_PARITY //Testing even parity
- sfr AUXR1 = 0xA2;
- #define UART_P1 0x80 //(AUXR1.7) switch RXD/TXD from P3.0/P3.1 to P1.6/P1.7
- sbit bit9 = P2^2; //P2.2 show UART data bit9
- bit busy;
- void SendData(BYTE dat);
- void SendString(char *s);
- void main()
- {
- AUXR1 |= UART_P1; //switch RXD/TXD from P3.0/P3.1 to P1.6/P1.7
- #if (PARITYBIT == NONE_PARITY)
- SCON = 0x50; //8-bit variable UART
- #elif (PARITYBIT == ODD_PARITY) || (PARITYBIT == EVEN_PARITY) || (PARITYBIT == MARK_PARITY)
- SCON = 0xda; //9-bit variable UART, parity bit initial to 1
- #elif (PARITYBIT == SPACE_PARITY)
- SCON = 0xd2; //9-bit variable UART, parity bit initial to 0
- #endif
- TMOD = 0x20; //Set Timer1 as 8-bit auto reload mode
- TH1 = TL1 = -(FOSC/12/32/BAUD); //Set auto-reload vaule
- TR1 = 1; //Timer1 start run
- ES = 1; //Enable UART interrupt
- EA = 1; //Open master interrupt switch
- SendString("STC10/11xx\r\nUart Test !\r\n");
- while(1);
- }
- /*----------------------------
- UART interrupt service routine
- ----------------------------*/
- void Uart_Isr() interrupt 4 using 1
- {
- if (RI)
- {
- RI = 0; //Clear receive interrupt flag
- P0 = SBUF; //P0 show UART data
- bit9 = RB8; //P2.2 show parity bit
- }
- if (TI)
- {
- TI = 0; //Clear transmit interrupt flag
- busy = 0; //Clear transmit busy flag
- }
- }
- /*----------------------------
- Send a byte data to UART
- Input: dat (data to be sent)
- Output:None
- ----------------------------*/
- void SendData(BYTE dat)
- {
- while (busy); //Wait for the completion of the previous data is sent
- ACC = dat; //Calculate the even parity bit P (PSW.0)
- if (P) //Set the parity bit according to P
- {
- #if (PARITYBIT == ODD_PARITY)
- TB8 = 0; //Set parity bit to 0
- #elif (PARITYBIT == EVEN_PARITY)
- TB8 = 1; //Set parity bit to 1
- #endif
- }
- else
- {
- #if (PARITYBIT == ODD_PARITY)
- TB8 = 1; //Set parity bit to 1
- #elif (PARITYBIT == EVEN_PARITY)
- TB8 = 0; //Set parity bit to 0
- #endif
- }
- busy = 1;
- SBUF = ACC; //Send data to UART buffer
- }
- /*----------------------------
- Send a string to UART
- Input: s (address of string)
- Output:None
- ----------------------------*/
- void SendString(char *s)
- {
- while (*s) //Check the end of the string
- {
- SendData(*s++); //Send current char and increment string ptr
- }
- }
-
- /********************************************************************
- 結束
- *********************************************************************/
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