; Write to location 0x12, data 0x34 and read it back. ; The MSSP module is used in I2C MASTER mode. #define BAUD D'100' ; Desired Baud Rate in kbps #define FOSC D'4000' ; Oscillator Clock in kHz #include ; Processor Include file, for standard names __CONFIG _FOSC_XT & _WDTE_OFF & _PWRTE_ON & _BOREN_OFF & _LVP_OFF & _CPD_OFF & _WRT_OFF & _CP_OFF varA EQU 20 varB EQU 21 varC EQU 22 varD EQU 23 BCD_Centenas EQU 24 ; de la RAM de usuario. Se toma a continuación de BCD_Decenas EQU 25 ; la última asignada. BCD_Unidades EQU 26 ORG 0 ; Start of code (location 0) ; *** Setup I/O *** clrf PORTA clrf PORTB ; PORTB pins set to drive low when enabled BANKSEL TRISC ; BANK 1 movlw B'10011000' ; RC3, RC4 are inputs for PORTC movwf TRISC ; Remaining PORTC I/O lines are outputs BANKSEL TRISB MOVLW B'00000000' movwf TRISB ; all PORTB pins configured for output mode ; (enables all PORTB drivers for driving LEDs) ; *** Setup Registers for I2C *** ; Configure MSSP module for Master Mode BANKSEL SSPCON movlw B'00101000' ; Enables MSSP and uses appropriate ; PORTC pins for I2C mode (SSPEN set) AND ; Enables I2C Master Mode (SSPMx bits) movwf SSPCON ; This is loaded into SSPCON ; Configure Input Levels and slew rate as I2C Standard Levels BANKSEL SSPSTAT movlw B'10000000' ; Slew Rate control (SMP) set for 100kHz movwf SSPSTAT ; mode and input levels are I2C spec, ; loaded in SSPSTAT ; Configure Baud Rate BANKSEL SSPADD movlw (FOSC / (4 * BAUD)) - 1 ; Calculates SSPADD Setting for movwf SSPADD ; desired Baud rate and sets up SSPADD ;-------------------CONFIGURO USART-------- BANKSEL CMCON MOVLW B'00000111' ;modulo comparador apagado MOVWF CMCON BANKSEL TXSTA MOVLW B'00100100' ;configuro el registro TXSTA MOVWF TXSTA BANKSEL SPBRG MOVLW D'25' ;cargo el registro SPBRG con la variable correpondiete segun la formula para 9600 baudios MOVWF SPBRG BANKSEL RCSTA MOVLW B'10010000' MOVWF RCSTA ; *** Begin I2C Data Transfer Sequences *** configuro_mpu: ;---------------------------- BANKSEL SSPCON2 ; BANK 1 bsf SSPCON2,SEN ; Generate START Condition call WaitMSSP ; Wait for I2C operation to complete movlw H'D0' call Send_I2C_Byte call WaitMSSP ; Wait for I2C operation to completeBANKSEL SSPCON2 btfsc SSPCON2,ACKSTAT ; Check ACK Status bit to see if I2C goto I2CFail ; failed, skipped if successful movlw 0x6B call Send_I2C_Byte call WaitMSSP BANKSEL SSPCON2 btfsc SSPCON2,ACKSTAT ; Check ACK Status bit to see if I2C goto I2CFail ; failed, skipped if successful movlw B'10000000' call Send_I2C_Byte call WaitMSSP BANKSEL SSPCON2 btfsc SSPCON2,ACKSTAT ; Check ACK Status bit to see if I2C goto I2CFail ; failed, skipped if successful BANKSEL SSPCON2 bsf SSPCON2,PEN ; Send STOP condition call WaitMSSP ; Wait for I2C operation to complet ;---------------------------- BANKSEL SSPCON2 ; BANK 1 bsf SSPCON2,SEN ; Generate START Condition call WaitMSSP ; Wait for I2C operation to complete movlw H'D0' call Send_I2C_Byte call WaitMSSP ; Wait for I2C operation to completeBANKSEL SSPCON2 btfsc SSPCON2,ACKSTAT ; Check ACK Status bit to see if I2C goto I2CFail ; failed, skipped if successful movlw 0x6B call Send_I2C_Byte call WaitMSSP BANKSEL SSPCON2 btfsc SSPCON2,ACKSTAT ; Check ACK Status bit to see if I2C goto I2CFail ; failed, skipped if successful movlw B'00000000' call Send_I2C_Byte call WaitMSSP BANKSEL SSPCON2 btfsc SSPCON2,ACKSTAT ; Check ACK Status bit to see if I2C goto I2CFail ; failed, skipped if successful BANKSEL SSPCON2 bsf SSPCON2,PEN ; Send STOP condition call WaitMSSP ; Wait for I2C operation to complet ;---------------------------- BANKSEL SSPCON2 ; BANK 1 bsf SSPCON2,SEN ; Generate START Condition call WaitMSSP ; Wait for I2C operation to complete movlw H'D0' call Send_I2C_Byte call WaitMSSP ; Wait for I2C operation to completeBANKSEL SSPCON2 btfsc SSPCON2,ACKSTAT ; Check ACK Status bit to see if I2C goto I2CFail ; failed, skipped if successful movlw 0x1A call Send_I2C_Byte call WaitMSSP BANKSEL SSPCON2 btfsc SSPCON2,ACKSTAT ; Check ACK Status bit to see if I2C goto I2CFail ; failed, skipped if successful movlw B'00000001' call Send_I2C_Byte call WaitMSSP BANKSEL SSPCON2 btfsc SSPCON2,ACKSTAT ; Check ACK Status bit to see if I2C goto I2CFail ; failed, skipped if successful BANKSEL SSPCON2 bsf SSPCON2,PEN ; Send STOP condition call WaitMSSP ; Wait for I2C operation to complet ;---------------------------- BANKSEL SSPCON2 ; BANK 1 bsf SSPCON2,SEN ; Generate START Condition call WaitMSSP ; Wait for I2C operation to complete movlw H'D0' call Send_I2C_Byte call WaitMSSP ; Wait for I2C operation to completeBANKSEL SSPCON2 btfsc SSPCON2,ACKSTAT ; Check ACK Status bit to see if I2C goto I2CFail ; failed, skipped if successful movlw 0x1B call Send_I2C_Byte call WaitMSSP BANKSEL SSPCON2 btfsc SSPCON2,ACKSTAT ; Check ACK Status bit to see if I2C goto I2CFail ; failed, skipped if successful movlw B'00000000' call Send_I2C_Byte call WaitMSSP BANKSEL SSPCON2 btfsc SSPCON2,ACKSTAT ; Check ACK Status bit to see if I2C goto I2CFail ; failed, skipped if successful BANKSEL SSPCON2 bsf SSPCON2,PEN ; Send STOP condition call WaitMSSP ; Wait for I2C operation to complet bsf PORTB,0 call retardo1s call retardo1s bcf PORTB,0 MOVLW 'O' ; envia caracter A CALL RS232_EnviaDato MOVLW 'K' ; envia caracter T CALL RS232_EnviaDato bsf PORTB,0 call retardo1s call retardo1s bcf PORTB,0 I2CRead: ; Send RESTART condition and wait for it to complete BANKSEL SSPCON2 bsf SSPCON2,RSEN ; Generate RESTART Condition call WaitMSSP ; Wait for I2C operation to complete ; Send and Check CONTROL BYTE, wait for it to complete movlw H'D0' ; Load CONTROL BYTE (input) call Send_I2C_Byte ; Send Byte call WaitMSSP ; Wait for I2C operation to complete ; Now check to see if I2C EEPROM is ready BANKSEL SSPCON2 btfsc SSPCON2,ACKSTAT ; Check ACK Status bit to see if I2C goto I2CRead ; ACK Poll waiting for EEPROM write to complete ; Send and Check ADDRESS BYTE, wait for it to complete movlw 0x43 ; Load ADDRESS BYTE call Send_I2C_Byte ; Send Byte call WaitMSSP ; Wait for I2C operation to complete BANKSEL SSPCON2 btfsc SSPCON2,ACKSTAT ; Check ACK Status bit to see if I2C goto I2CFail ; failed, skipped if successful ; Send REPEATED START condition and wait for it to complete bsf SSPCON2,RSEN ; Generate REPEATED START Condition call WaitMSSP ; Wait for I2C operation to complete ; Send and Check CONTROL BYTE (out), wait for it to complete movlw H'D1' ; Load CONTROL BYTE (output) call Send_I2C_Byte ; Send Byte call WaitMSSP ; Wait for I2C operation to complete BANKSEL SSPCON2 btfsc SSPCON2,ACKSTAT ; Check ACK Status bit to see if I2C goto I2CFail ; failed, skipped if successful ; Switch MSSP module to I2C Receive mode bsf SSPCON2,RCEN ; Enable Receive Mode (I2C) ; Get the DATA BYTE and wait for it to complete. Data is in SSPBUF when done. ; The receive mode is disabled at end automatically by the MSSP module. call WaitMSSP ; Wait for I2C operation to complete ; Send NACK bit for Acknowledge Sequence BANKSEL SSPCON2 bsf SSPCON2,ACKDT ; ACK DATA to send is 1, which is NACK. bsf SSPCON2,ACKEN ; Send ACK DATA now. ; Once ACK or NACK is sent, the ACKEN is automatically cleared by the MSSP ; Send and Check the STOP condition and wait for it to complete. bsf SSPCON2,PEN ; Send STOP condition call WaitMSSP ; Wait for I2C operation to complete ; I2C Write and Read have both finished, the value is output on LEDs. BANKSEL SSPBUF ; BANK 0 movf SSPBUF,W ; Get data from SSPBUF into W register call BIN_a_BCD call RS232_EnviaDato MOVLW H'0D' ; nueva linea call BIN_a_BCD CALL RS232_EnviaDato MOVLW H'0A' ; nueva linea call BIN_a_BCD CALL RS232_EnviaDato call retardo1s ; Program has finished and completed successfully. goto I2CRead ; *** SUBROUTINES & ERROR HANDLERS *** ; I2C Operation Failed code sequence - This will normally not happen, ; but if it does, a STOP is sent and the entire code is tried again. I2CFail: BANKSEL SSPCON2 bsf SSPCON2,PEN ; Send STOP condition call WaitMSSP ; Wait for I2C operation to complete BANKSEL PORTB ; BANK 0 movlw 0x01 ; Turn on all LEDs on PORTB movwf PORTB ; to show error condition goto $ ; Wait forever at this location Send_I2C_Byte: BANKSEL SSPBUF ; BANK 0 movwf SSPBUF ; Get value to send from W, put in SSPBUF retlw 0 ; Done, Return 0 WaitMSSP: BANKSEL PIR1 ; BANK 0 btfss PIR1,SSPIF ; Check if done with I2C operation goto WaitMSSP ; I2C module is not ready yet bcf PIR1,SSPIF ; I2C module is ready, clear flag. Retlw 0 ; Done, Return 0 ;-------------------ENVIO DE DATOS SERIAL------- RS232_EnviaDato: MOVWF TXREG BCF STATUS, RP1 ;accedo al banco 1 BSF STATUS, RP0 espero: BTFSS TXSTA,TRMT ;verifico que ya se envio GOTO espero BCF STATUS, RP1 ;accedo al banco 0 BCF STATUS, RP0 RETURN espera_dato: BTFSS PIR1,RCIF GOTO espera_dato si_hay_error: BTFSC RCSTA,OERR CALL error1 BTFSC RCSTA,FERR CALL error2 MOVF RCREG,W RETURN error1: BCF RCSTA,CREN BSF RCSTA,CREN RETURN error2: MOVF RCREG,W RETURN ;-------------------BIN a BCD------------------- BIN_a_BCD: clrf BCD_Centenas ; Carga los registros con el resultado inicial. clrf BCD_Decenas ; En principio las centenas y decenas a cero. movwf BCD_Unidades ; Se carga el número binario a convertir. BCD_Resta10: movlw .10 ; A las unidades se les va restando 10 en cada subwf BCD_Unidades,W ; pasada. (W)=(BCD_Unidades) -10. btfss STATUS,C ; ¿C = 1?, ¿(W) positivo?, ¿(BCD_Unidades)>=10? goto BIN_BCD_Fin ; No, es menor de 10. Se acabó. BCD_IncrementaDecenas: movwf BCD_Unidades ; Recupera lo que queda por restar. incf BCD_Decenas,F ; Incrementa las decenas y comprueba si ha llegado movlw .10 ; a 10. Lo hace mediante una resta. subwf BCD_Decenas,W ; (W)=(BCD_Decenas)-10). btfss STATUS,C ; ¿C = 1?, ¿(W) positivo?, ¿(BCD_Decenas)>=10? goto BCD_Resta10 ; No. Vuelve a dar otra pasada, restándole 10 a BCD_IncrementaCentenas: ; las unidades. clrf BCD_Decenas ; Pone a cero las decenas incf BCD_Centenas,F ; e incrementa las centenas. goto BCD_Resta10 ; Otra pasada: Resta 10 al número a convertir. BIN_BCD_Fin: swapf BCD_Decenas,W ; En el nibble alto de (W) también las decenas. addwf BCD_Unidades,W ; En el nibble bajo de (W) las unidades. return ; Vuelve al programa principal. ;-------------------RETARDOS-------------------- retardo1s: MOVLW D'4' MOVWF varC bucleext2: MOVLW D'252' MOVWF varB bucleext: MOVLW D'247' MOVWF varA bucleint: NOP DECFSZ varA,F GOTO bucleint DECFSZ varB,F GOTO bucleext DECFSZ varC,F GOTO bucleext2 MOVLW D'13' ;cargo varD para aproximarme mas aun al tiempo de retaro deseado MOVWF varD regfina: DECFSZ varD,F GOTO regfina NOP NOP RETURN END