16f84a running interrupt PICBASIC code

[divaker]

Please see the attached code.

It has two parts, one to vary the content of a variable using a single button and second an interrupt run to output RB0 based on the variable content.

When it is simed on MPLAB, it is quite OK. But when it is run on the chip, it does not work.
(with WDT switched off)
However the two parts when compiled as separate files to check the code, they function well on the chip.

Please help me solve the prob

Thanks

[Archangel]

You post your code in PDF format, and the only way anyone can test it is to retype it all over, no thanks.

[savnik]

You post your code in PDF format, and the only way anyone can test it is to retype it all over, no thanks.

I post the code from PDF.

    '16f84a

    Symbol OUT_PIN = PORTB.0            ' Output to solenoid RB0
    Symbol LED = PORTB.1                ' Control button to RB1
    Symbol CNTL_BUTTON = PORTB.7        ' Control button to RB7
    
    spacing var byte
    temp var byte
    
    TRISA = $FF
    TRISB = $FC                         ' RB0 and RB1 outputs, others input
    spacing = 15
    LED = 0
    temp = 1
    
    gosub wait_button
    
    LED = 1
    pause 2000                          ' Wait for two seconds
    if CNTL_BUTTON = 1 then spacing = 30: goto direct   ' If button is released before 2 secs
                                                        ' code goes directly into the default spacing
    temp = 0
    gosub wait_button                   ' If button is pressed more than 2 secs,
                                        ' it gets caught here and waits for release
    LED = 0
    pause 1000                          ' Wait for 100 ms
    
repeata:
    spacing = spacing + 5               ' Increase the spacing count by 2 every time
    toggle LED
    pause 1000
    toggle LED
    if spacing = 45 then spacing = 20   ' Till it reaches maximum and reset to minimum
    temp = 1
    gosub wait_button                   ' Access the push button state and repeat if short press
    pause 2000                          ' Delay for 2 seconds
    if CNTL_BUTTON = 1 then goto repeata
    LED = 1
    OUT_PIN = 0
'Calculate the value to be loaded into TMR0 for counting at RA4 connected to the encoder output
'Use a multiplier to convert the spacing in cm to number of pulses to count
'Say if the distance measuring wheel's dia is 40 cm then its circumference = 3.14*40 appr = 125 cm
'For one revolution ie 125 cm distance traveled = 500 pulse outputs of encoder
'Correspondingly 500/125 = 4 pulses/cm distance, therefore set the count as 255 - (spacing * 4)
direct:
    spacing = 255 - (spacing * 4)
    OPTION_REG = %00110000              ' TMR0 counter on falling edge of RA4
    'Cnt = 0                            ' Clear the event counter, Cnt
    ON INTERRUPT GOTO ISR               ' Interrupt service routine
    TMR0 = spacing
    OUT_PIN = 0
    INTCON = %10100000                  ' Enable TMR0 overflow interrupt
    
NXT:
    if OUT_PIN = 1 then
        pause 300
        OUT_PIN =0
    endif
    GOTO NXT                            ' Continue
    
'This is the interrupt service routine, ISR. The program jumps here whenever TMR0 overflow occurs
    DISABLE                             ' Disable interrupts
ISR:                                    ' Entry point of the ISR
    OUT_PIN = 1
    TMR0 = spacing
    INTCON = %10100000                  ' Enable TMR0 overflow interrupt
    RESUME                              ' Resume main program
    ENABLE                              ' Enable interrupts
    
wait_button:
    if CNTL_BUTTON && 1 = temp then wait_button
    return
    end

[divaker]

You post your code in PDF format, and the only way anyone can test it is to retype it all over, no thanks.

Sorry that I had attached it in pdf
Now I have attached in text.
Please pardon me.

[skimask]

When it is simed on MPLAB, it is quite OK. But when it is run on the chip, it does not work.

And you're sure the PIC is running in the first place?
How does the 'blinky LED' program run?

[divaker]

Dear skimask,
Yes, the "blinky and the button" worked as required right on the PIC16f84.
Similarly the interrupt driven routine also worked well separately on the PIC
But when these two are put together on the PIC it odes not work.

Though the MPLAB simulates it well enough and comes thru'.


Divaker

[skimask]

Looks to me like you have to do some big time reorganization of your program...You've got it jumping all over everything...
Here's how I normally do things...might not be optimal, but it keeps me out of trouble:
Defines
Variable declarations
ASsembly macros
Skip over Int Handler/Subroutines
On Interrupt statement
Int Handler routine
Subroutines
PIC, PIC pins and other hardware Setup/Initialization
Main body

And besides all that, I don't see where you clear the TMR0 overflow flag like it says you have to do in the datasheet. I see you enable the TMR0 interrupt a couple of times which has the side effect of clearing the flag...but probably not at the right time.

[divaker]

Dear skimask,
Thanks for your time and the suggestions.
Let me reorganize and see. Also I will clear the TMR0 approp.
However, I wonder how come the interrupt routines without the blink button works absolutely alright on the PIC.
And when I removed the whole button routines and rewrote the code to accept the variable 'spacing' from PORTA through a DIP switch, the code worked without hitch on the PIC.

Divaer

[skimask]

However, I wonder how come the interrupt routines without the blink button works absolutely alright on the PIC.
And when I removed the whole button routines and rewrote the code to accept the variable 'spacing' from PORTA through a DIP switch, the code worked without hitch on the PIC.

Divaer

Probably because the blink button code had PAUSEs in it. The 'On Interrupt' doesn't fire if it's blocked by a PAUSE or any other statement that needs to complete before the next statement can execute. More details about 'On Interrupt' in the manual.