; WRITTEN BY: TOM SCARFF ; DATE: 28/2/2000 ; ITERATION: 1.0 ; FILE SAVED AS: drm_vel2.ASM ; FOR: PIC16F877 ; CLOCK: 4.00 MHz CRYSTAL ; INSTRUCTION CLOCK: 1.00 MHz T= luS ; PROGRAMME FUNCTION: To read trigger i/p's on PORTB ; A/D data in for 8 i/p's ; and to transmit it to MIDI out. list p=16F877 ; tells the assembler which PIC #include "p16F877.inc" ; general register file ;******************************** ; Constant Assignments ;******************************** RCIF equ 05h ;******************************** ; Variable Assignment Addresses ;***t**************************** ; 20h Start of General purpose registers AD_DATA EQU 21h ADRES EQU 22h dlyreg2 equ 23h dlyreg3 equ 24h drum equ 25h vel1 equ 26h vel2 equ 27h value1 equ 28h count equ 29h max_cnt equ 2Ah val1 equ 2Bh val2 equ 2Ch val3 equ 2Dh val4 equ 2Eh val5 equ 2Fh val6 equ 30h val7 equ 31h val8 equ 32h base_addr equ 33h LED equ 34h drum_sel equ 35h select equ 36h max equ 37h sens_flag equ 38h sens equ 39h ; 7fh end of data area ;************************************ ; PROGRAMME Reset Point ;************************************ org 00 ; reset vector goto init ;************************************ ; Switch Debounce Delay (100mS) ;************************************ sw_dbnc movlw 80h ; Delay routine movwf dlyreg2 debnce call delay3 decfsz dlyreg2 goto debnce return ;************************************* ; Delay Subroutine (770uS) ;************************************* delay3 movlw .255 movwf dlyreg3 dly3 decfsz dlyreg3 goto dly3 nop return ;****************************************** ; Receive Data subroutine ;****************************************** rxchar btfss PIR1,RCIF ; test for incoming data goto $-1 movfw RCREG return ;****************************************** ; transmission complete subroutine ;***************+************************** txchar bsf STATUS,RP0 btfss TXSTA,1 ; test for end of transmission goto $-1 bcf STATUS,RP0 return ;********************************************* ; Start A/D conversion Subroutine ;********************************************* convert bsf ADCON0,2 ;set GO/DONE Bit loop1 btfsc ADCON0,2 goto loop1 rrf ADRESH,W andlw 07Fh movwf AD_DATA return ;*********************************#*** ; Output MIDI note-on data ;************************************** noteon movlw 099h ; Note-on Channel 10 movwf TXREG ; send chazacter from W call txchar movf drum,W movwf TXREG ; send character from W call txchar movf vel1,W movwf TXREG ; send character from W call txchar return ;*********************************#*** ; Output MIDI note-off data ;************************************** noteoff movlw 089h ; Note-off Channel 10 movwf TXREG ; send chazacter from W call txchar movf drum,W movwf TXREG ; send character from W call txchar movf vel1,W movwf TXREG ; send character from W call txchar return ;********************************************* ; Detect Peak value of Drum hit ;*+******************************************* peak clrf vel1 movlw .20 movwf max_cnt peak0 call convert call convert movf AD_DATA,W movwf vel2 subwf vel1,W ; (f) - (W)--> (dest) btfsc STATUS,C ; Skip if result -Ve. ie f vel1 movwf vel1 decfsz max_cnt goto peak0 return ;********************************************* ; Detect Sensitivity of 1st Drum hit ;*+******************************************* sens_piezo movlw 07Fh movwf max movf vel1,W subwf max,W ; max-W-->W andlw 07Fh movwf sens bcf sens_flag,0 return ;************************************ ; EEPROM Read ;************************************ ee_read bcf STATUS,RP0 bsf STATUS,RP1 ; bank 2 movwf EEADR bsf STATUS,RP0 bsf STATUS,RP1 ; bank 3 bsf EECON1,RD r1 btfsc EECON1,RD ; Wait to finish read. goto r1 bcf STATUS,RP0 ; now bank 2 movf EEDATA,W andlw 07Fh ; prevent value >127 bcf STATUS,RP1 ; now bank 0 return ;***************************************************** ; Table to convert drum sound ;***************************************************** drm_type movlw 01h subwf select,W btfsc STATUS,Z goto sel1 movlw 02h subwf select,W btfsc STATUS,Z goto sel2 movlw 03h subwf select,W btfsc STATUS,Z goto sel3 movlw 04h subwf select,W btfsc STATUS,Z goto sel4 movlw 05h subwf select,W btfsc STATUS,Z goto sel5 movlw 06h subwf select,W btfsc STATUS,Z goto sel6 movlw 07h subwf select,W btfsc STATUS,Z goto sel7 movlw 08h subwf select,W btfsc STATUS,Z goto sel8 retlw 00h sel1 movf val1,W movwf drum return sel2 movf val2,W movwf drum return sel3 movf val3,W movwf drum return sel4 movf val4,W movwf drum return sel5 movf val5,W movwf drum return sel6 movf val6,W movwf drum return sel7 movf val7,W movwf drum return sel8 movf val8,W movwf drum return ;***************************************************** ; Table to select A/D Channel ;***************************************************** channel addwf PCL retlw 00h ; dummy 00 not used in 'count' retlw B'01000001' ; channel 0 retlw B'01001001' ; channel 1 retlw B'01010001' ; channel 2 retlw B'01011001' ; channel 3 retlw B'01100001' ; channel 4 retlw B'01101001' ; channel 5 retlw B'01110001' ; channel 6 retlw B'01111001' ; channel 7 retlw 00h ;**************************** ; initalise software ;**************************** init bcf STATUS,RP0 ;page 0 clrf PORTA clrf PORTB clrf PORTC clrf PORTD clrf PORTE ;Set up A/D Converter bsf STATUS,RP0 bcf STATUS,RP1 movlw 0FFh movwf TRISD ;all inputs movlw 0FFh movwf TRISA ;all inputs movlw 07h movwf TRISE movlw 0FFh ; all inputs movwf TRISB bcf STATUS,RP0 ; return to page 0 bsf STATUS,RP0 clrf ADCON1 bcf STATUS,RP0 ; return to page 0 ; Set up USART bsf STATUS,RP0 ; goto page 1 movlw b'10001000' ; RC7 is RX input movwf TRISC ; RC3 is Prog. Sw. movlw 01h ; 31250 baud for MIDI movwf SPBRG movlw b'00100000' ; async tx 8 bit movwf TXSTA bcf STATUS,RP0 ; return to page 0 movlw b'10010000' ; async rx 8 bit movwf RCSTA bsf STATUS,RP0 movlw 07h ; rtcc/256 movwf OPTION_REG bcf STATUS,RP0 ;************************************** ; Main Programme Start ;************************************** ;************************************** ; Programme EEPROM if Prog. Sw. selected ;************************************** main0 btfsc PORTC,3 ; is prog. sw. pressed? goto main1 call sw_dbnc bsf STATUS,RP0 bcf STATUS,RP1 movlw 00h movwf TRISD ; all outputs for LED's bcf STATUS,RP0 ; return to page 0 movlw 00h movwf base_addr movlw 08h movwf count movlw 0FEh ; 1111 1110 movwf LED loop0 movf LED,W ;turn on next/LED movwf PORTD movf PORTB,W ; read 8-way switch andlw 07Fh ; 0 to 127! only movwf drum_sel movf base_addr,W; start addr. EEPROM bsf STATUS,RP1 ; bank 2 movwf EEADR bcf STATUS,RP1 ; bank 0 movf drum_sel,W andlw 07Fh bsf STATUS,RP1 ; bank 2 movwf EEDATA bsf STATUS,RP0 ;writing to eeprom, bank 3 ;;;;;; bcf INTCON,GIE bsf EECON1,WREN movlw 55h movwf EECON2 movlw 0AAh movwf EECON2 bsf EECON1,WR test_wr btfsc EECON1,WR; is write finished? goto test_wr bcf STATUS,RP0 bcf STATUS,RP1 ; now bank 0 ;;;;;;; bsf INTCON,GIE btfss PORTC,3 ; is prog. sw. released? goto $-1 call sw_dbnc btfsc PORTC,3 ; is prog. sw. pressed? goto $-1 call sw_dbnc incf base_addr bsf STATUS,C rlf LED,F ; from 0 to 7 decfsz count ;from 8 to 1 goto loop0 ;************************************** ; Main Programme Start ; Read EEPROM and write to val1 to 8 ;************************************** main1 clrf base_addr ; start addr. of EEPROM at 00h? movf base_addr,W call ee_read movwf val1 incf base_addr,F movf base_addr,W call ee_read movwf val2 incf base_addr,F movf base_addr,W call ee_read movwf val3 incf base_addr,F movf base_addr,W call ee_read movwf val4 incf base_addr,F movf base_addr,W call ee_read movwf val5 incf base_addr,F movf base_addr,W call ee_read movwf val6 incf base_addr,F movf base_addr,W call ee_read movwf val7 incf base_addr,F movf base_addr,W call ee_read movwf val8 incf base_addr,F ;----------------------------------------- bsf STATUS,RP0 ; set PORTD for i/p's bcf STATUS,RP1 movlw 0FFh movwf TRISD ; all inputs for drums bcf STATUS,RP0 ; return to page 0 bsf sens_flag,0 ; set to 0000 0001 clrf sens clrf PORTD main movf PORTD,W movwf value1 comf value1,F btfsc STATUS,Z ; is any i/p 'low'? goto main movlw 00h movwf count drum? incf count,F rrf value1 btfss STATUS,C goto drum? movf count,W movwf select call drm_type ; returns with drum-type in 'drum' movf count,W call channel ; returns a/d channel movwf ADCON0 call convert call convert call peak ; returns with velocity=vel1 ; btfsc sens_flag,0 ; call sens_piezo ; movf sens,W ; addwf vel1,F ; W+vel1-->vel1 ; movf vel1,W ; btfsc vel1,7 ; test MSB, >127? ; movlw 07Fh ; yes then set to 127 ; movwf vel1 ; no call noteon call delay3 call delay3 call delay3 call delay3 call noteoff goto main end