Beginner in need of help !!

[robbo78]

Ive decided to go the interrupt route... I am stuck already. Here is my simple code, why isnt my interrupt working?

#CONFIG 
   __config _INTRC_OSC_NOCLKOUT & _WDT_ON & _MCLRE_OFF & _CP_OFF
#ENDCONFIG

DEFINE OCS 4 '4mhz ocsillator
ANSEL = 0 'all I/O digital
CMCON0 = 7 'comparator off
LED VAR GPIO.0 'LED pin 7
LED2 VAR GPIO.1 'LED2 pin 6

ON INTERRUPT GOTO mode1 'interrupt handler is mode1
INTCON = %10001000 'enable gp3 interrupt

main:
ENABLE
HIGH LED 'led on
PAUSE 500 'delay 0.5 second
LOW LED 'led off
PAUSE 500 'delay 0.5 second
GOTO main 'repeat

DISABLE 'disable interrupts in handler
mode1:
HIGH LED2 'led2 on
PAUSE 50
LOW led2 'led2 off
PAUSE 50
RESUME 'return to where left off
ENABLE 'enable interrupts

[mackrackit]

Normally in the interrupt routine this is needed.
INTCON.1 = 0
But the data sheet for this chip reads like this is needed.
INTCON.0 = 0

Then at the beginning of your code below
INTCON = %10001000
add
IOC.3=1

I think...

[robbo78]

Normally in the interrupt routine this is needed.
INTCON.1 = 0
But the data sheet for this chip reads like this is needed.
INTCON.0 = 0

Then at the beginning of your code below
INTCON = %10001000
add
IOC.3=1

I think...

Brilliant, that got it working. I take it IOC.3 = 1 tells the chip when to interrupt & on what pin?

So INTCON = %10001000 tells it to enable interrupts on pin 3 & IOC.3 = 1 tells it to interrupt on pin 3 change ?

Thanks for your help,
Rob

[Tabsoft]

This should work for you. It works in my simulator.

Also, since PBP's ON INTERRUPT only checks to see if an interrupt has occurred between PBP commands, you may want to use a loop counter in your main routine and use short pauses. This is how I revised your code.

Comments are added to the code below.

Good Luck.

'PIC 12F683
#CONFIG 
   __config _INTRC_OSC_NOCLKOUT & _WDT_ON & _MCLRE_OFF & _CP_OFF
#ENDCONFIG

'DEFINE OCS 4 '4mhz ocsillator
DEFINE OSC 4 '4mhz ocsillator
ANSEL = 0 'all I/O digital
CMCON0 = 7 'comparator off
LED VAR GPIO.0 'LED pin 7
LED2 VAR GPIO.1 'LED2 pin 6

loop1 var byte  ' Loop 1 Counter

ON INTERRUPT GOTO mode1 'interrupt handler is mode1
INTCON = %10001000 'enable GIE and GPIE; clear GPIF
IOC = %00001000 ' enable IOC3 (GPIO3 Interrupt on change)

ENABLE 
main:
do
    for loop1 = 1 to 50
        HIGH LED 'led on
        'PAUSE 500 'delay 0.5 second
        pause 10    '10 ms
    next loop1
    
    for loop1 = 1 to 50
        LOW LED 'led off
        'PAUSE 500 'delay 0.5 second
        pause 10    '10 ms
    next loop1

'GOTO main 'repeat
loop

DISABLE 'disable interrupts in handler
mode1:
if INTCON.0 = 1 then    'one of the GPIO<5:0> pins changed state (must be cleared in software)

    HIGH LED2 'led2 on
    PAUSE 50
    LOW led2 'led2 off
    PAUSE 50

endif
INTCON = %10001000  'enable GIE and GPIE; clear GPIF

RESUME 'return to where left off
ENABLE 'enable interrupts

end 'got here by mistake

[robbo78]

This should work for you. It works in my simulator.

Also, since PBP's ON INTERRUPT only checks to see if an interrupt has occurred between PBP commands, you may want to use a loop counter in your main routine and use short pauses. This is how I revised your code.

Comments are added to the code below.

Good Luck.

'PIC 12F683
#CONFIG 
   __config _INTRC_OSC_NOCLKOUT & _WDT_ON & _MCLRE_OFF & _CP_OFF
#ENDCONFIG

'DEFINE OCS 4 '4mhz ocsillator
DEFINE OSC 4 '4mhz ocsillator
ANSEL = 0 'all I/O digital
CMCON0 = 7 'comparator off
LED VAR GPIO.0 'LED pin 7
LED2 VAR GPIO.1 'LED2 pin 6

loop1 var byte  ' Loop 1 Counter

ON INTERRUPT GOTO mode1 'interrupt handler is mode1
INTCON = %10001000 'enable GIE and GPIE; clear GPIF
IOC = %00001000 ' enable IOC3 (GPIO3 Interrupt on change)

ENABLE 
main:
do
    for loop1 = 1 to 50
        HIGH LED 'led on
        'PAUSE 500 'delay 0.5 second
        pause 10    '10 ms
    next loop1
    
    for loop1 = 1 to 50
        LOW LED 'led off
        'PAUSE 500 'delay 0.5 second
        pause 10    '10 ms
    next loop1

'GOTO main 'repeat
loop

DISABLE 'disable interrupts in handler
mode1:
if INTCON.0 = 1 then    'one of the GPIO<5:0> pins changed state (must be cleared in software)

    HIGH LED2 'led2 on
    PAUSE 50
    LOW led2 'led2 off
    PAUSE 50

endif
INTCON = %10001000  'enable GIE and GPIE; clear GPIF

RESUME 'return to where left off
ENABLE 'enable interrupts

end 'got here by mistake

Hi Tabsoft, that worked perfectly. I can see what you mean by using loops instead of pauses, the interrupt is much more reactive.

Now I just need to know how to stay in that interrupt routine until I tap the button again.

Thanks,
Rob

[HenrikOlsson]

Hi Rob,

Now I just need to know how to stay in that interrupt routine until I tap the button again.

Even though that would work for this particular application that's generally not what you want to do (ie stay in the interrupt routine). Instead you do as I showed earlier, use a flag/semaphore in the interrupt service routine which the main code reads and determines what to do.

The same thing applies to your scenario with ten states. You have a variable which you increment in the interrupt (ie once very time you press the button), once it gets to 10 you reset it to zero. Then, in the main program loop you simply check the value of this variable and act accordingly. With a bit of thought and some math you might even USE the variables value directly as the delay in your loop to blink the LED.

As for the analog input it's important to understand that there is no mechanism to automatically run the ADC and detect (ie interrupt) when the voltage at the input changes. You need to write code to sample the input once every minute, second, millisecond or whatever the requirement may be.

Finally, please don't quote the full message just posted. There's really no need to have the very latest post quoted in full.

/Henrik.

[Tabsoft]

Rob,

Glad it worked for you.

I'm not sure if you want/need to stay in the ISR as I don't know your final objective.

I would suggest using a flag to determine the state of the IOC.3 interrupt coming from your button.
Then in the ISR change the state of the flag each time the interrupt occurs and then get out of the ISR.
You can then setup a subroutine for what you wanted to accomplish in the ISR.
Finally in your main loop check the state of the flag and gosub to the new subroutine.

Here is a working example. Expanded on what I posted last time.

'PIC 12F683
#CONFIG 
   __config _INTRC_OSC_NOCLKOUT & _WDT_ON & _MCLRE_OFF & _CP_OFF
#ENDCONFIG

'DEFINE OCS 4 '4mhz ocsillator
DEFINE OSC 4 '4mhz ocsillator
ANSEL = 0 'all I/O digital
CMCON0 = 7 'comparator off
LED VAR GPIO.0 'LED pin 7
LED2 VAR GPIO.1 'LED2 pin 6

loop1 var word  ' Loop 1 Counter (word for 0 to 65535 increments)
loop2 var byte  ' Loop 2 Counter (byte used for 0 to 255 increments)
ModeFlag var bit   ' Bit to determine what state of IOC.3 is

'*****Initlaze Vars*****
   loop1 = 0
   loop2 = 0
ModeFlag = 0
'***********************

ON INTERRUPT GOTO mode1 'interrupt handler is mode1
INTCON = %10001000 'enable GIE and GPIE; clear GPIF
IOC = %00001000 ' enable IOC3 (GPIO3 Interrupt on change)

ENABLE 
main:
do
    for loop1 = 1 to 500
        HIGH LED 'led on
        'PAUSE 500 'delay 0.5 second
        pause 1    '1 ms
        if ModeFlag = 1 then
        gosub moderoutine
    endif
    
    next loop1
    
    for loop1 = 1 to 500
        LOW LED 'led off
        'PAUSE 500 'delay 0.5 second
        pause 1    '1 ms
        if ModeFlag = 1 then
        gosub moderoutine
    endif
    
    next loop1

'GOTO main 'repeat
loop

moderoutine:
    do while ModeFlag = 1
        high LED2   'LED2 On
        for loop2 = 0 to 50
            pause 1 '1ms
        next loop2
        
        low LED2    'LED2 Off
        for loop2 = 0 to 50
            pause 1 '1ms
        next loop2 
    loop    

    return

DISABLE 'disable interrupts in handler
mode1:
if INTCON.0 = 1 then    'one of the GPIO<5:0> pins changed state (must be cleared in software)

    'HIGH LED2 'led2 on
    'PAUSE 50
    'LOW led2 'led2 off
    'PAUSE 50

    'Set the ModeFlag
    ModeFlag = ~ ModeFlag
endif
INTCON = %10001000  'enable GIE and GPIE; clear GPIF

RESUME 'return to where left off
ENABLE 'enable interrupts

end 'got here by mistake