Beginner in need of help !!

[robbo78]

Hi Tabsoft, I got the comparator working perfectly so I decided to move onto adding an interrupt, which believe it or not hasn't worked. Here is the code I have fully written, maybe you can help where I have gone wrong?

Thanks,
Rob

You will probably have a laugh at this, as its probably completely wrong lol

'PIC 12F683

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

PAUSE 20 'wait for hardware to settle

DEFINE OSC 4 '4mhz ocsillator
ANSEL = %00000010 'pin 6 analog
CMCON0 = %00000100 'comparator mode
VRCON = %10101000 'voltage reference
TRISIO = %00000010 'pin 6 input

ON INTERRUPT GOTO SLSELECT 'interrupt handler is slselect
INTCON = %11001000 'enable GIE and GPIE; clear GPIF
IOC = %00000010 ' enable IOC1 (GPIO.1 Interrupt on change)
PIE1 = %00001000 'enable comparator interrupt

POT1 VAR CMCON0.6 'read potentiometer
LED VAR GPIO.2 'led pin 5

ENABLE
main:
HIGH LED 'light led
GOTO main 'repeat

DISABLE 'disable interrupts in handler
SLSELECT:
IF POT1 = 1 THEN 'if <1.1v sleep
NAP 1
ELSE
ENDIF

INTCON = %10001000  'enable GIE and GPIE; clear GPIF
PIR1 = %00000000 'reset CMIF
RESUME 'where left off
ENABLE 'enable interrupts

[Tabsoft]

Glad to hear if Rob.

You did not say what is happening only that it is not working.
I took a look at your code and several things jump out at me.

1. You are jumping into the deep end of the pool with testing "nap"
If would take a smaller step first. Set a flag in the ISR and resume. Then in the main act on the flag you set in the ISR.
This way you can see the effects of the ISR logic.
2. You have IOC.1 enabled, which is GP1, which you are using for the comparator. You need to comment out IOC.1.
3. You are not testing for which Interrupt is firing inside of your ISR. It is almost always a good practice to determine what interrupt caused the jump to the ISR.
4. At the end of your ISR you are not setting the INTCON register they way you think. I believe you have a typo in the value you are assigning to it.


I changed your code to the following which shows the changes.

'PIC 12F683

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

PAUSE 20 'wait for hardware to settle

DEFINE OSC 4 '4mhz ocsillator
ANSEL = %00000010 'pin 6 analog
CMCON0 = %00000100 'comparator mode
VRCON = %10101000 'voltage reference
TRISIO = %00000010 'pin 6 input

ON INTERRUPT GOTO SLSELECT 'interrupt handler is slselect
INTCON = %11001000 'enable GIE and GPIE; clear GPIF
'IOC = %00000010 ' enable IOC1 (GPIO.1 Interrupt on change)
PIE1 = %00001000 'enable comparator interrupt

POT1 VAR CMCON0.6 'read potentiometer
LED VAR GPIO.2 'led pin 5

bitTest var bit 'Debug test bit.  Set/Clear in ISR and Check in maiin

bitTest = 0

ENABLE
main:
    
    'HIGH LED 'light led
    LED = bitTest
    
GOTO main 'repeat

DISABLE 'disable interrupts in handler
SLSELECT:
    'IF POT1 = 1 THEN 'if <1.1v sleep
        'NAP 1
    'ELSE
    'ENDIF
    if PIR1.3 = 1 then  'Comparator Interrupt fired (must be cleared before resume)
        bitTest = POT1
    endif

    'INTCON = %10001000  'enable GIE and GPIE; clear GPIF
    INTCON =%11001000 
    PIR1 = %00000000 'reset CMIF
    RESUME 'where left off
    ENABLE 'enable interrupts

See if this gets you along further.

[robbo78]

Hi Tabsoft, okay thanks for all that. I will go back to flagging. I think I was
Getting a bit ahead of myself lol.

Let you know how it goes

[robbo78]

Hi, okay I've been playing about with comparator interrupt now & think I have got the hang of it using flags. The code below is something little I came up with

Now I think I would like to implement the nap command now, or do you think I should learn something else before jumping to the nap command?

Thanks again,
Rob

'PIC 12F683

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

PAUSE 50 'wait for hardware to settle

DEFINE OSC 4 '4mhz ocsillator
ANSEL = %00000010 'pin 6 analog
CMCON0 = %00000100 'comparator mode
VRCON = %10101000 'voltage reference
TRISIO = %00000010 'pin 6 input

ON INTERRUPT GOTO int1 'interrupt handler is int1
INTCON = %11001000 'enable GIE and GPIE; clear GPIF
PIE1 = %00001000 'enable comparator interrupt

POT1 VAR CMCON0.6 'read potentiometer
LED VAR GPIO.2 'led pin 5
loop1 var word 'loop1 counter

bitTest var bit 'Debug test bit.  Set/Clear in ISR and Check in main

bitTest = 0
Loop1 = 0

ENABLE
main:

IF bittest = 1 THEN 
GOTO FLASH
ENDIF
    
LOW LED

GOTO main


ENABLE
FLASH:



do
for loop1 = 1 to 1000
HIGH LED
PAUSE 1

NEXT LOOP1

for loop1 = 1 to 1000
LOW LED
PAUSE 1

NEXT LOOP1

IF bittest = 0 THEN
GOTO main
ENDIF

LOOP
  
    
DISABLE 'disable interrupts in handler
int1:
    
if PIR1.3 = 1 then  'Comparator Interrupt fired (must be cleared before resume)
BITtest = pot1
ENDIF 

INTCON =%11001000 
PIR1 = %00000000 'reset CMIF
RESUME 'where left off
ENABLE 'enable interrupts

[Tabsoft]

Rob,

Looks like you got it working.

One little thing though.
The Pause command is based upon the "DEFINE OSC" value to calculate the pause interval correctly.
It is a good practice to have your "DEFINE OSC" statement up top in the source code before you use any time sensitive commands such as "Pause x".

The way you have your program setup the following occurs, which I presume you have seen in practice on your physical system.
The LED on GP2(pin5) will stay LOW (OFF) while the voltage input on GP1(pin6) is above your reference voltage.
The LED GP2(pin5) will blink in 1sec intervals while the voltage input on GP1(pin6) is below your reference voltage.

This works fine on my simulator.

Good job!

It looks like you're ready for a "nap" now.

[robbo78]

Hi Tabsoft, thanks for comfirming also thanks again for all your help, I wouldnt have got to this point if it wasnt for you. I havent got a simulator so I just test straight on the BB.

I will drop the pause below the osc value, thanks for that tip

Do I implement the nap command in the same way as flashing an LED? So if bittest = 1 : nap 1, if bittest = 0 : goto main? Something like that ?

Thanks again,
Rob

[Tabsoft]

Rob,

Why don't you check this out.

'PIC 12F683

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


DEFINE OSC 4 '4mhz ocsillator
ANSEL = %00000010 'pin 6 analog
CMCON0 = %00000100 'comparator mode
VRCON = %10101000 'voltage reference
TRISIO = %00000010 'pin 6 input

PAUSE 50 'wait for hardware to settle

ON INTERRUPT GOTO int1 'interrupt handler is int1
INTCON = %11001000 'enable GIE and GPIE; clear GPIF
PIE1 = %00001000 'enable comparator interrupt

POT1 VAR CMCON0.6 'read potentiometer
LED VAR GPIO.2 'led pin 5
loop1 var word 'loop1 counter

bitTest var bit 'Debug test bit.  Set/Clear in ISR and Check in main


high LED    'Start with LED ON
pause 500   'Pause .5 secs so you can see the LED turn on

bitTest = POT1  'Take initial reading of input voltage state
Loop1 = 0

ENABLE
main:

    IF bitTest = 1 THEN 'input voltage is < reference voltage  
        low LED
        nap 1
    else    'bitTest = 0 - input voltage is > reference voltage
        GOTO FLASH
    ENDIF
        
    GOTO main


ENABLE
FLASH:
    do
        for loop1 = 1 to 1000
            HIGH LED
            PAUSE 1
        NEXT LOOP1
        
        for loop1 = 1 to 1000
            LOW LED
            PAUSE 1
        NEXT LOOP1
        
        IF bitTest = 1 THEN
            GOTO main
        ENDIF
    
    LOOP
  
    
DISABLE 'disable interrupts in handler
int1:
    
if PIR1.3 = 1 then  'Comparator Interrupt fired (must be cleared before resume)
bitTest = pot1
ENDIF 

INTCON =%11001000 
PIR1 = %00000000 'reset CMIF
RESUME 'where left off
ENABLE 'enable interrupts