;************************************************************************************ ; Software License Agreement ; ; The software supplied herewith by Microchip Technology Incorporated (the "Company") ; for its PICmicro(r) Microcontroller is intended and supplied to you, the Company's ; customer, for use solely and exclusively on Microchip PICmicro Microcontroller ; products. ; ; The software is owned by the Company and/or its supplier, and is protected under ; applicable copyright laws. All rights are reserved. Any use in violation of the ; foregoing restrictions may subject the user to criminal sanctions under applicable ; laws, as well as to civil liability for the breach of the terms and conditions of ; this license. ; ; THIS SOFTWARE IS PROVIDED IN AN "AS IS" CONDITION. NO WARRANTIES, WHETHER EXPRESS, ; IMPLIED OR STATUTORY, INCLUDING, BUT NOT LIMITED TO, IMPLIED WARRANTIES OF ; MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE APPLY TO THIS SOFTWARE. THE ; COMPANY SHALL NOT, IN ANY CIRCUMSTANCES, BE LIABLE FOR SPECIAL, INCIDENTAL OR ; CONSEQUENTIAL DAMAGES, FOR ANY REASON WHATSOEVER. ; ;************************************************************************************ ; ; Filename: OpticalInt.asm ; Date: March 21,2005 ; File Version: 1.00 ; ; Company: Microchip Technology Inc. ; ; ;************************************************************************************ ; ; Files required: ; OpticalInt.inc ; LCD.asm ; LCD.inc ; 16F917.lkr ; ;************************************************************************************ ; ; Notes: This project controls the speed of a brushed DC motor. POT1 is used to ; set the speed of the motor. The optical interrupter provides speed ; feedback. This feedback is fed into the T1CKL pin and the speed of the ; motor is measured. The speed is then displayed on the LCD as RPM / 10^3. ; ; Connections: ; POT1 (J4) to RA0 (J13) ; Optical Interrupter (J7) to RC5 (J10) ; N2 (J1) to CCP2 (J10) ; P1 (J1) to RD7 (J10) ; ;************************************************************************************ #include ;********************************************************************** STARTUP code goto Initialize PORT1 code ;************************************************************************************ ; Initialize - Initialize CCP1, comparators, internal oscillator, I/O pins, ; analog pins, motor parameters, variables ; ;************************************************************************************ Initialize clrf STATUS ; bank 0 bsf STATUS,RP0 ; we'll set up the bank 1 Special Function Registers fist ; Configure I/O pins for project bcf TRISD,7 ; RD7 is an output bcf TRISD,2 ; RD6 is an output bsf TRISC,5 ; RC5 is an input bsf TRISA,4 ; RA4 is an input bsf TRISA,0 ; RA0 is an input ; Set internal oscillator frequency movlw b'01110000' ; 8Mhz movwf OSCCON ; Set up A-to-D Module movlw b'00000001' ; enable AN0 movwf ANSEL movwf b'01010000' ; Fosc/16 movwf ADCON1 ; Configure PR2 to movlw 0x3F ; 31.2 kHz PWM movwf PR2 ; Set TMR0 parameters MOVLW B'10000111' ;PORTB PULL-UP DISABLED MOVWF OPTION_REG ;TMR0 RATE 1:256 ; Turn off comparators movlw 0x07 movwf CMCON0 ; turn off comparators bcf STATUS,RP0 ; go back to bank 0 ; Finish setting up A-to-D Module movlw b'00000001' ; left justified, AN0 selected, module on movwf ADCON0 ; Turn off all interrupts clrf INTCON ; Make sure interrupts are turn off ; Configure Capture Compare PWM Module 2 clrf CCPR2L movlw b'00001100' ; pwm mode movwf CCP2CON ; Turn on Timer 2 bsf T2CON,TMR2ON ; turn on PWM ; Turn on Timer 1 movlw b'00010111' ; set Timer 1 prescaler to 1:2, Select external clock source, Timer 1 on movwf T1CON clrf PORTD ; Turn off Motor ;************************************************************************************ ; Main - Every 23.4ms POT1 is measured and moved into the dutycycle registers for ; CCP2. CCP2 drives the brushed dc motor, thereby controlling the speed. Timer 1 ; is clocked by the Optical Interrupter. Every 3/4 of a second the value in Timer 1 ; is converted to RPM and displayed as: RPM / 10^3. ; ;************************************************************************************ Main bsf ADCON0,GO_DONE ; start an A-to-D conversion call InitLCD ; Initialize LCD Special Function Registers clrf Counter clrf TMR1L clrf TMR1H Loop btfss INTCON,T0IF ; TMR0 is preloaded so than this loop is exited every 23.4ms goto Loop ; RPM/10 = (number of counts every 23.ms) * 256 (this is a nice number to work with) bcf INTCON,T0IF movlw .73 movwf TMR0 call SetMotorSpeed call MeasureSpeed btfsc STATUS,C call DisplaySpeed goto Loop SetMotorSpeed movf ADRESH,w movwf DutyCycle bsf ADCON0,GO_DONE bsf P1 ; Turn on motor swapf DutyCycle,w ; bits 4 and 5 of CCP2CON andlw 0x30 iorlw 0x8D movwf CCP2CON rrf DutyCycle,f ; move most significant 6 bits of duty cycle into rrf DutyCycle,w ; CCPR2L andlw 0x3F movwf CCPR2L return MeasureSpeed incf Counter,f ; measure over 3^5 or 32 cycles (23.4ms * 32 = 0.75 second) bcf STATUS,C ; clear carry flag btfss Counter,5 goto EndMeasureSpeed clrf Counter bcf T1CON, TMR1ON ; turn off Timer 1 movf TMR1L,w ; Store Timer 1 in TimeL and TimeH movwf TimeL movf TMR1H,w movwf TimeH bsf T1CON,TMR1ON ; turn Timer 1 back on clrf TMR1L clrf TMR1H bsf STATUS,C ; Set carry flag to indicate its time to display a value EndMeasureSpeed return DisplaySpeed bcf STATUS,C ; first multiply by 8 (0.75sec * 8 = 6 seconds = 1/10 of a minute) rlf TimeL,f rlf TimeH,f rlf TimeL,f rlf TimeH,f rlf TimeL,f rlf TimeH,f movf TimeL,w ; Now convert to BCD movwf L_byte movf TimeH,w movwf H_byte call ConvertToBCD ; This function was taken from AN526 (why write a function if you don't have too?!) ; It converts the RPM number to Binary Coded Decimal (BCD) movf R2,w ; Example RPM = 4320 andlw 0x0F ; R2 contains 0x32 (remember we are displaying RPM/10) call DisplayDigit1 swapf R2,w andlw 0x0F call DisplayDigit2 movf R1,w ; R1 contains 0x04 andlw 0x0F call DisplayDigit3 call Display3DP ; Place a decimal point between the 4 and the 3. The display will read 4.32 return ; Therefor the display shows RPM / 10^3. ;************************* Taken from AN526 ********************************** ; Binary To BCD Conversion Routine ; This routine converts a 16 Bit binary Number to a 5 Digit ; BCD Number. This routine is useful since PIC16C55 & PIC16C57 ; have two 8 bit ports and one 4 bit port ( total of 5 BCD digits) ; ; The 16 bit binary number is input in locations H_byte and ; L_byte with the high byte in H_byte. ; The 5 digit BCD number is returned in R0, R1 and R2 with R0 ; containing the MSD in its right most nibble. ; ; Performance : ; Program Memory : 35 ; Clock Cycles : 885 ; ; ; Program: B16TOBCD.ASM ; Revision Date: ; 1-13-97 Compatibility with MPASMWIN 1.40 ; ;*******************************************************************; ConvertToBCD bcf STATUS,0 ; clear the carry bit movlw .16 movwf count clrf R0 clrf R1 clrf R2 loop16 rlf L_byte, F rlf H_byte, F rlf R2, F rlf R1, F rlf R0, F ; decfsz count, F goto adjDEC RETLW 0 ; adjDEC movlw R2 movwf FSR call adjBCD ; movlw R1 movwf FSR call adjBCD ; movlw R0 movwf FSR call adjBCD ; goto loop16 ; adjBCD movlw 3 addwf 0,W movwf temp btfsc temp,3 ; test if result > 7 movwf 0 movlw 30 addwf 0,W movwf temp btfsc temp,7 ; test if result > 7 movwf 0 ; save as MSD RETLW 0 END ; directive 'end of program'