Simple ISR?

[MOUNTAIN747]

My project is a 24hr temp logger. Which logs every 15 minutes for the 24hr period. The 15 minute timer is the PBP “SLEEP” command. After 24 hours the application goes to sleep” @sleep”. I want an interrupt on GP2 external interrupt pin to stop the 15min. timer or the “@sleep” and send the program to a PBP routine to RS232 dump to PC. At that time the job is done, unit goes to low power state until power disconnect. I don’t want to use ON INTERRUPT, can’t wait 15min. to print. Once interrupted I don’t need to save any variables, or STATUS or PCLATH (<2k) logging is done, I only need a “goto _printout” placed at location 04. So how do I accomplish that? AND have I missed something of the process?

@ DEVICE PIC12F683,MCLR_OFF,INTRC_OSC_NOCLKOUT ,WDT_ON,BOD_OFF
@ DEVICE PWRT_ON,FCMEN_OFF,IESO_OFF,PROTECT_ON
OSCCON=%1110000    
Define OSC 8

     VRCON  = 0         
     ADCON0 = 0         
     OPTION_REG = %01000000  	;rising edge
     ANSEL  = 0    			;digital all
     CMCON0 = 7
     INTCON = %10010000         	;Globle set, GP2 ext int, flg clr
     GPIO=0   
     TRISIO=%00001100		;GPIO.2 input	
	;GPIO.2 held low until button push +5v
     Blink   var GPIO.4

     GOTO Start
     define INTHAND myint
     asm
          myint goto _printlog
            endasm
Start:  
              -----     LOG DATA for 24hrs
Printlog:
	 -----     RS232 to PC
	INTCON = %10010000   ;in the case another print out is needed      
	@sleep

I’ve written a small INT test program to work this out but I’m not having any luck. On compile I get the error “undefined symbol myint” & “opcode expected instead of myint”
I remove the myint from the asm line and the opcode error goes away. However I think this is needed as it is the ASM label. This ASM method is right out of the 2.60 manual. What is it I’m not getting? Comments Please!

[Jerson]

I tried out your code. The only change that needs to be done is in how you define myint

myint goto _printlog

myint should start in the 1st column of your file.

[MOUNTAIN747]

Thank you Jerson for your reply. I did not understand the relevance of the first column positions of the instruction. As a matter of fact the manual has the instruction on the first column. This should get me up and running. Thank you again for your response

[MOUNTAIN747]

I have written this short piece of code to test the interrupt. IT Works! but only ONCE... For some reason it will not interrupt the second time unless I reset the processor with the power. I can't see a problem. I am resetting INTCON before return to main program. ???

[

@ DEVICE PIC12F683,MCLR_OFF,INTRC_OSC_NOCLKOUT ,WDT_ON,BOD_OFF
@ DEVICE PWRT_ON,FCMEN_OFF,IESO_OFF,PROTECT_OFF
OSCCON=%1110000    
Define OSC 8

     VRCON   =  0         
     ADCON0 =  0         
     OPTION_REG = %01000000  	;rising edge
     ANSEL   =  0    		;digital all
     CMCON0=  7
     INTCON = %10010000         	;GlE set, INTE set, INTF clr
     GPIO=0   
     TRISIO  = %00001100		;GPIO.2 input
      Avar    var byte
      Blink   var GPIO.4
      TX      var GPIO.5
      GOTO Main
define INTHAND myint

asm
myint goto _printlog
endasm
    
Main:  
            
Blinkled:
    pause 1000
    for Avar=1 to 4
    HIGH    blink  
    pause   100
    low     blink
    pause 200
    next Avar
            
    Serout2 tx, 84, ["   This is a test, This is only a test",13,10,13,10]  ;print to PC             
    goto Blinkled
printlog:            
    Serout2 tx, 84, ["   An Interrupt has occured on GP2",13,10,13,10]           
    INTCON=%10010000  ;set GIE, INTE and clear INTF
    goto Main     
    end

[Jerson]

your printlog is an ISR (interrupt service routine) and should end with a return not a goto main. Try that

[MOUNTAIN747]

Jerson,
Yes, I had forgotten about the address that was pushed on the stack by the interrupt. I tried a RETURN and @RETFIE , the micro locked up for a couple of seconds then restarted, I think by WDT, and would not re-interrupt. I know I have to deal with the stack but RETURN will load an address I don’t want to use. So my challenge it to find a way to POP the stack, discard the address and load a new address while still resetting interrupt bits. It looks like there is NO easy way to do this. I’m sure that is why DT_INT is so popular. By the way thanks again for lending a helping hand to the struggling hobbyist, mainly me. I’ll keep working on this problem and post any success.
WANTED: easy way to use Ext Interrupt to change the course of a program.