Pulse generation using PIC12f629

[VRL_15]

I am using PIC12f629 to generate a pulse and I want the on time 44ms and off time 44 ms(millisec).
Please let me know a code that will generate this pulse.

Thanks and Best Regards

 

[VRL_15]

list p=12f629, f=inhx32
#include <p12f629.inc>

__CONFIG _WDT_OFF&_INTRC_OSC_NOCLKOUT&_BODEN_ON&_CP_OFF&_PWRTE_ON



;COUNTER equ 0x21
;ANSEL equ 0x9F
cblock 0x20
d1
d2
endc
;**********************************************************************
ORG 0x000 ; processor reset vector
goto init ; go to beginning of program


ORG 0x004 ; interrupt vector location
init:
call 0x3FF ; retrieve factory calibration value
bsf STATUS,RP0 ; set file register bank to 1
movwf OSCCAL ; update register with factory cal value
bcf STATUS,RP0 ; set file register bank to 0
CLRF GPIO ;Init GPIO
MOVLW 07h ;Set GP<2:0> to
MOVWF CMCON ;digital IO
BSF STATUS,RP0 ;Bank 1
;CLRF ANSEL ;Digital I/O
MOVLW b'00011111' ;Sets inputs and outputs
MOVWF TRISIO ;and set outputs
BCF STATUS,RP0 ;Bank 0
;movlw 20h
;movwf GPIO
;movlw 02h
;movwf COUNTER
goto main
main:

call lowtest
;decfsz COUNTER,1
goto main

lowtest:
bsf GPIO,5
call Delay
bcf GPIO,5
call Delay
return

Delay:

movlw 0x97
movwf d1
movlw 0x09
movwf d2

Delay_0:
decfsz d1, f
goto $+2
decfsz d2, f
goto Delay_0
goto $+1
return
end

 

[VRL_15]

I used the above code and got the pulse but I want to be able to manually change the milliseconds inside the code itself so that I can change the on time and off time in milliseconds instead of using the delay loop I have used in my code right now.

I would really appreciate your help.

Thank you

 

[colin55]

The following delay sub-routine produces 1mS delay. Change the .1 (decimal one) to .44 for 44mS delay etc.

delay  movlw    .1
       movwf    mS_file
       nop
       decfsz    temp,f
       goto        $-2
       decfsz    mS_file,f
       goto       $-4        ;each loop = 1mS
       retlw      00

 

[VRL_15]

Thank you

It worked.

Thanks a lot

I am getting a stack underflow error when I want to display only three pulses.

The code works for continuous stream of pulses but not for specific number of pulses.

I have replaced the code for the delay with the one you suggested.

 

[VRL_15]

Following is my new code:

list p=12f629, f=inhx32
#include <p12f629.inc>

__CONFIG _WDT_OFF&_INTRC_OSC_NOCLKOUT&_BODEN_ON&_CP_OFF&_PWRTE_ON

COUNTER equ 0x21
COUNTER1 equ 0x22
temp equ 0x23
M1 equ 0x24
M2 equ 0x25
M3 equ 0x26
;ANSEL equ 0x9F
;cblock 0x20
;d1
; d2
;endc
;**********************************************************************
ORG 0x000 ; processor reset vector
goto init ; go to beginning of program


ORG 0x004 ; interrupt vector location
init:
call 0x3FF ; retrieve calibration value
bsf STATUS,RP0 ; set file register bank to 1
movwf OSCCAL ; update register with factory cal value
bcf STATUS,RP0 ; set file register bank to 0
CLRF GPIO ;Init GPIO
MOVLW 07h ;Set GP<2:0> to
MOVWF CMCON ;digital IO
BSF STATUS,RP0 ;Bank 1
;CLRF ANSEL ;Digital I/O
MOVLW b'00011111' ;Sets inputs and outputs
MOVWF TRISIO ;and set outputs
BCF STATUS,RP0 ;Bank 0
;movlw 20h
;movwf GPIO
;movlw 02h
;movwf COUNTER

;Variable definitions
;M1 on time of pulse
;M2 off time of pulse
;M3 number of pulses
;M4 on time of pulse
;M5 off time of pulse
;M6 number of pulses

movlw .10 ;on time of pulse #1
movwf M1
movlw .34 ;off time of pulse #1
movwf M2
movlw 02h ;number of pulse #1
movwf M3


main: decfsz M3,1
call lowtest
;decfsz M3,1
goto loop1

lowtest:
bsf GPIO,5
call Delay
bcf GPIO,5
call Delay1
return
;decfsz M3,1
;goto main
;goto loop1

Delay movf M1,0
movwf COUNTER
nop
decfsz temp,f
goto $-2
decfsz COUNTER,f
goto $-4
retlw 00


Delay1 movf M2,0
movwf COUNTER1
nop
decfsz temp,f
goto $-2
decfsz COUNTER1,f
goto $-4
retlw 00
loop1: ;nop
;goto $-2
end

 

[VRL_15]

I have to control the number of pulses to be displayed.
But the above code is not working.

I am getting the CORE-E0002 Stack underflow error.

Please let me know if anybody has an idea to solve this problem.

Thanks and Best Regards,
Vishal

 

[Mosaic]

Trace your calls and returns, somehow you are hitting a return without a matching call.

 

[VRL_15]

How can we see pulses on GPIO4 and GPIO5 at the same time?