;*************************************************************************** ;****** ;****** Digital ignition for 2 stroke engines. SPORTDEVICES 1/9/2005 ;****** ;****** ;****** Digital parts: PIC16F84 ;****** ;****** ;**************************************************************************** list p=16F84a #include p16F84a.inc radix dec __CONFIG _WDT_OFF & _XT_OSC ;setup values #define prescaler 7 #define scr_pulse 200 ;us for pulse, it DOESN'T change spark duration #define min_period 31 #define max_period 60000000/128/min_rpm #define pickup PORTB,0 ;pin 6 #define output PORTA,2 ;pin 1 #define LED PORTA,4 ;pin 1 #define TMR0 1 ;please note previous version was: "cblock 8", then the first 4 variables overwrote ;the last 4 Special Function Registers of the PIC, and the program didn't work cblock 0x0c ;first free memory address!!! tmr0h,perl,perh,first,del endc org 0x00 GOTO MAIN ;counter high bits org 0x04 INCF tmr0h,f BCF INTCON,2 retfie #define sizeof_ignition 57 read_array: ; movlw ignition addwf PCL,f ignition: retlw 88 retlw 91 retlw 93 retlw 96 retlw 99 retlw 102 retlw 105 retlw 108 retlw 110 retlw 113 retlw 116 retlw 119 retlw 122 retlw 125 retlw 128 retlw 130 retlw 133 retlw 139 retlw 142 retlw 145 retlw 147 retlw 150 retlw 153 retlw 156 retlw 159 retlw 162 retlw 164 retlw 167 retlw 170 retlw 173 retlw 176 retlw 179 retlw 182 retlw 184 retlw 187 retlw 190 retlw 193 retlw 196 retlw 199 retlw 201 retlw 204 retlw 207 retlw 210 retlw 213 retlw 216 retlw 219 retlw 221 retlw 224 retlw 227 retlw 230 retlw 236 retlw 238 retlw 241 retlw 244 retlw 247 retlw 250 retlw 253 wait_pulse: ;active on falling ; while (!input(pikcup)); //wait line goes high waithigh: BTFSS pickup GOTO waithigh ; while (input(pickup)); //wait line goes low waitlow: BTFSC pickup GOTO waitlow ;perl=tmr0l; perh=tmr0h; islow: MOVF TMR0,W MOVWF perl MOVF tmr0h,W MOVWF perh ;TMR0=0; tmr0l=0; tmr0h=0; CLRF TMR0 CLRF tmr0h retlw 0 ;} ;**************** MAIN: BSF STATUS,5 ; set_tris_b(0x01); //PIN B0 input (hall_sensor) MOVLW 01 MOVWF TRISB ;B0: pickup input MOVLW 0 MOVWF TRISA ;A2: output MOVLW prescaler-1 ;2^prescaler=128 MOVWF OPTION_REG BCF STATUS,5 BSF first,0 ; first=true; CLRF tmr0h MOVLW 0xA0 ;INTCON=0xa0; //T0IE=1 MOVWF INTCON BCF output ; output_low(output); //active high ;**************** main_loop: CALL wait_pulse ; first pulse is not processed because the period can not be calculated until the second pulse ; if(first) { wait_pulse(); first=false; } BTFSS first,0 GOTO nowait CALL wait_pulse BCF first,0 ; first=false ;if (!perh && (perl>=min_period)&&(perl=min_period+sizeof(ignition0))) out_map: MOVF perh,F BTFSS STATUS,2 GOTO LOW_RPM MOVLW min_period+sizeof_ignition SUBWF perl,W BTFSS STATUS,0 ; GOTO HIGH_RPM (disabled) GOTO silent ;LOW RPM RANGE (<5000) ;********************* LOW_RPM: INCF perh,F ;perh++ INCF perl,F ;perl++ BCF LED loop2: ;low_rpm_multiple=20 MOVLW (20-5)/3 MOVWF del loop3: DECFSZ del,F GOTO loop3 ; DECFSZ perl,F GOTO loop2 DECFSZ perh,F GOTO loop2 BSF LED GOTO DO_PULSE ;HIGH RPM RANGE (>15000) (disabled) ;*********************** HIGH_RPM: INCF perl,F ;perl++; BCF LED loop4: ;high_rpm_multiple 10 us //0 degrees MOVLW 2 MOVWF del loop5: DECFSZ del,F GOTO loop5 ;** DECFSZ perl,F BSF LED GOTO loop4 ;******* DO_PULSE: BSF output ;output_high(output); MOVLW scr_pulse/3 MOVWF del loop9: DECFSZ del,F GOTO loop9 BCF output ;output_low(output); ;silent_time, 768 us (256*3) silent: CLRF del loop10: DECFSZ del,F GOTO loop10 GOTO main_loop END