单片机红外通信.doc

单片机的红外数据通信

;*****************************************************************
;IrDA CODE FOR MAX-3100 UART- 8051 based
;  Written by: Wettroth 9/13/96- Maxim Integrated Products
;
;MAX-3100 UART demonstration and test code for the 8051 that
;bidirectionally translate IrDA to 232 and 232 to IrDA.  Both the
;8051 and IrDA sides run at 9600 baud.   All receivers are polled
;to keep code easy to follow.  Testing was done with an HP-100
;Palmtop for IrDA and PC running a terminal program.  The primary
;purpose of the code is to demonstrate the UART.
;***************************************************************
; CONSTANTS
PCON    EQU     87H
;PORT PIN DEFINITIONS- BIT BANGING IF
DOUT    BIT     P1.0           ;data out (from uart)
DIN     BIT     P1.1           ;data in (from UART)
SCLK    BIT     P1.2           ;serial clock
CS      BIT     P1.3           ;chip select- act low
IRQ     BIT     P3.2           ;(irq) polled in this code
;RAM LOCATIONS
TX1     EQU     10H            ;transmit regs
TX2     EQU     11H
RX1     EQU     12H            ;receive regs
RX2     EQU     13H
;***************************************************************
        ORG     0H
BEGIN:  MOV     SP,#70H        ;initialize stack
        CLR     SCLK           ;clear sclk - normally low
;initialize 8051 internal uart
        MOV     TMOD,#20H      ;t1 baud
        MOV     TH1,#253       ;reload value baud 9600/xtal 5.5M
        MOV     SCON,#50H      ;uart- m1, tx and rx
        MOV     PCON,#80H      ;double baud rate bit
        MOV     TCON,#40H      ;start baud timer
;initialize max3100 uart- irda mode at 9600 baud
        MOV     TX1,#0E4H      ;high byte of config- R ints
        MOV     TX2,#0CAh      ;9600 baud irda mode and two stops
        CALL    UTLK           ;send to uart- write config
;************** MAIN ROUTINE LOOP **********************
LOOP:   JNB     IRQ,URCV       ;data avail from 3100 uart?
NRECV:  JBC     RI,RCV51       ;check for 8051 rcv- tx out irda
        JMP     LOOP           ;hang here forever
;byte recieved from 3100 uart- get it and send out 8051 uart
URCV:   MOV     TX1,#0         ;read data
        MOV     TX2,#0         ;read data
        CALL    UTLK           ;send to 8051 uart- get data to rx
        MOV     A,RX2          ;get data to acc
        MOV     SBUF,A         ;send out on RS-232 side 9600 baud
        JMP     LOOP           ;back to top
;byte recieved from 8051 uart- get it and send out 3100 uart
RCV51:  MOV     A,SBUF         ;data from 8051 uart
        MOV     TX1,#80H       ;tx data
        MOV     TX2,A          ;data to irda
        CALL    UTLK           ;send to uart- send data out IrDA
        JMP     LOOP           ;back to top
;**********************************************************
;SUBROUTINES
; UTLK- talk to uart- main routine
;       send 16 bits from TX1 TX2 and rcv 16 to RX1 RX2
UTLK:   CLR     CS             ;activate cs
        MOV     A,TX1          ;get high byte
        CALL    BYT8           ;send out
        MOV     RX1,A          ;get recieved 1
        MOV     A,TX2          ;get high byte
        CALL    BYT8           ;send out
        MOV     RX2,A          ;get recieved 2
        SETB    CS             ;set CS high
        RET                    ;DONE
;*************************
; BYT8- shift out & in 8 bits with spi clocking- from and to acc
BYT8:   MOV     R4,#8          ;8 bits to send
        SETB    DIN            ;make sure din is input
B8LP:   RLC     A              ;get msb of acc to carry
        MOV     DOUT,C         ;put out on pin
        SETB    SCLK           ;clock high- clock
        MOV     C,DIN          ;get data after clk high
        CLR     SCLK           ;clock low
        MOV     ACC.0,C        ;put in lsbit of a
        DJNZ    R4,B8LP        ;loop til 8 bits
        RET                    ;done
; end of code
        END