Hello,

I would to modify the source in order to be able to count single short
event pulses up to 1kHz repetition.
At the moment it is restricted to 25 Hz (did not understand yet how)


The code example is here:

EVENT:  call RESETE     ;reset required working bytes, and set screen
        movlw 100       ;initial basic CLKCNT val for secs timing
        movwf CLKCNT
EVNT2:  btfsc PORTA,3   ;is MODE switch pressed?
        goto ROUTE      ;yes
        btfsc PORTA,4   ;is RESET still pressed?
        goto EVNT2      ;yes
        comf PORTB,W    ;is RB6/RB7 high (depending on MASK)?
        andwf MASK,W
        btfsc STATUS,Z
        goto EVNT2      ;yes
        bcf INTCON,2    ;no, so clear timer flag and start timing

INTRPT:                 ;working interrupt routine for event counting
        btfss INTCON,2  ;has a timer time-out been detected?
        goto INTRPT     ;no
        bcf INTCON,2    ;yes (NB, max input rate via this route is 25Hz)
call CLKIN
        btfsc PORTA,3   ;is MODE switch pressed?
        goto ROUTE      ;yes
        btfsc PORTA,4   ;is reset needed?
        goto EVENT      ;yes

TSTBT1: comf PORTB,W    ;is RB7/RB6 high
        andwf MASK,W
        btfss STATUS,Z
        goto TSTPRV     ;yes
        bcf TSTFLG,7    ;no, clear data flag
        goto INTRPT
TSTPRV: btfsc TSTFLG,7  ;is data flag high?
        goto INTRPT     ;yes
        bsf TSTFLG,7    ;no, set data flag high
        incf COUNT1,F   ;inc count
        btfss STATUS,Z
        goto TSTBT4
        incf COUNT2,F
        btfss STATUS,Z
        goto TSTBT4
        incf COUNT3,F
TSTBT4: call DISPLY
        goto INTRPT

The full code is here:
ftp.epemag.wimborne.co.uk/pub/PICS/eventcounter

The P16F84A ports are:
RB6,RB7 - inputs
RB0-RB3 - D4-D7 on the LCD
RB4  -  RS
RB5  -  E
RA2-RA4 input buttons
clock 3,2768 MHz

I will strongly appreciate any help and advice how to modify the code, in
order to detect short event pulses, (durattion in microseconds)

Thank you for the understanding and kind support

Best Regards

Pavlik





-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist