12f675_fuse_about_to_blow!

[LEDave]

I'm having major problems trying to get the TX program to do what I want it to, namely TX after a timing loop executes. Just for information, if I comment out the timing loop the program TX's no problem and sends and receives a test WORD.

Here's the setup:

INTCON = %00001000  ' Enable port change wakeup from sleep

WPU = %00010000     ' pull-up on for GPIO.4 (external pull-up already on GPIO.3)

It's GPIO.4 we're looking at here. That's the pin that will receive the input from a 555 timer / potential divider using an ldr to detect that it's dark and therefore TX the days count over.

OPTION_REG = %00001111 'Watch_Dog_Timer ON with a 128 prescaler

Here's the main body of the program. it's a little bit of a mess because I've commented out the GPIO.3 COUNTS part of the program and also added then commented out INTCON.0 = 0 in various places to try and get it to do the timer loop / COUNT then TX.

IF GPIO.3= 1 AND GPIO.4= 1 THEN ' Nothing has happened so SLEEP
       E_OUT=0       ' Disable transmitter
       INTCON.0 = 0  ' No Inputs detected or it's still light so clear int on change flag
       @ SLEEP       ' and start snoozin..zzzzzzzzzzz indefinatly
       @ NOP         ' Do nothing for 1st instruction on wake-up
  ELSE  
   'IF  GPIO.3=0 THEN GOSUB COUNTS 'Bird detected at box - GOTO LABEL COUNTS   
   IF  GPIO.4=0 THEN DARK   'It's got dark? or just cloudy - GOTO LABEL DARK
  ENDIF     
  GOTO MAIN          'Back to sleep / continue counting
    
    
 'COUNTS:
    '  VISITS = VISITS +1 'Bird at box so increment counter
    '  INTCON.0 = 0       ' Clear int on change flag
  'RETURN                 ' Then back to sleep....
     
      DARK:
      
      'INTCON.0 = 0     ' Clear int on change flag
                       ' It could be night time...It might only be a cloud though...   
                       ' so back to sleep / wake / sleep for half an hour..zwzwzw

      COUNTER=0        ' clear before entry
WHILE COUNTER < 2      ' 4.608sec Loop time (Loop for 30 mins = 781)
     @ SLEEP
     COUNTER=COUNTER+1
     'IF  GPIO.3= 0  THEN COUNTS 'Bird at box (it's not dark) so continue counting
WEND     
              
    if  GPIO.4= 0  then ENCODE  ' It really ia dark so carry on and transmit VISITS
    
    'IF  GPIO.4= 1  THEN Main  '(changed from return) It's not dark after all so carry_on_sleeping_counting 
    
Encode:  
    E_OUT=1     ' Turn transmitter on 
    pauseus 25  ' Let transmitter settle
    DAT_OUT = %10101001
   
    'INTCON.0 = 0  ' Clear int on change flag
      
    'Build checksum of 2 data bytes
    CHK_SUM = (DAT_OUT * 2)    
    
Transmit:
    'LET VISITS = VISITS / 2  'Just VISITS too not from the box 
    LET VISITS = 300 'Test data number
    SEROUT2 D_OUT,BAUD,[PreAmble,Synch,DAT_OUT,DAT_OUT,CHK_SUM,VISITS.highbyte,VISITS.lowbyte]
    PAUSE GUARD ' 5mS guard time gives decoder time to respond,calculate,change,etc.
    INTCON.0 = 0  ' Clear int on change flag - moved here from above
    GOTO Main
        
    END

I think the problem maybe that the COUNTER loop never gets completed because the IOC which comes from GPIO.4 isn't reset and the counter loop is using @SLEEP but never gets that far.

Any ideas greatfully received.

Dave

[mackrackit]

What happens if the @SLEEP below is commented?

WHILE COUNTER < 2      ' 4.608sec Loop time (Loop for 30 mins = 781)
     @ SLEEP
     COUNTER=COUNTER+1
     'IF  GPIO.3= 0  THEN COUNTS 'Bird at box (it's not dark) so continue counting
WEND

[LEDave]

What happens if the @SLEEP below is commented?

It TX's straight away and the led on the Pickit1 (receiver) flashes three times (as intended). There is no 5 sec delay from the timing loop though.

It's as if the timing loop COUNT is just being bypassed, have I set it up right?

Dave

[LEDave]

If I press and hold down push button GP4 on the transmitter, the receiver flashes the led continually. I would have thought / was expecting that when the push button on GPIO.4 was pressed and held down you would get a four / five second delay before the receiver received anything and started to flash.

Tonights silly question:

How does setting the OPTION reg and WDT then become associated with the loop COUNTER? The WDT has a period of 18ms so setting the bits 111 gives 128*18ms =2.304secs the COUNTER loop should run twice giving a delay of 4.608secs right? But if the program doesn't read COUNTER as being associated with the WDT it's going to count to two in a flash and it will appear that the TX sends the data instantly(which is what is happening). Should the WDT and COUNTER be 'joined' via a 'SYMBOL statement in the program under SYMBOL? or something like this?

Dave

[mackrackit]

Just guessing as I have not done this before...

WHILE COUNTER <= 2      ' 4.608sec Loop time (Loop for 30 mins = 781)
      INTCON.0 = 0
     @ SLEEP
     COUNTER=COUNTER+1
     'IF  GPIO.3= 0  THEN COUNTS 'Bird at box (it's not dark) so continue counting
WEND

I hope someone else will jump in on this...

[LEDave]

Hi mackrackit,

I've made the changes and the Transmitter lights the it's reference led about once every nine seconds but doesn't transmit at all (doesn't seem to get that far).

I still can't get my head around how the WDT associates with the loop COUNTER, plus the more I read on this it seems that if the WDT isn't reset back to zero before it reaches FF+1 (I think) it then reboots the program which makes sense....Mmm, more reading and thinking to do, interesting though.

Dave

[cncmachineguy]

First let me say, this is an awesome thread. I have been meaning to read it from the beginning, but I am a slow reader.

LEDave, WDT in the snippet you just posted works like this:
Assuming PBP knows you are using the WDT, clear WD is sprinkled around the program for you to keep from resetting the chip. But to get to these, the program must run.

@sleep basically stops the program and the chip just, well sleeps. Because of this, the WDT never gets cleared. The WD can wake up the PIC, so when WDT overflows, the PIC wakes up and resumes where it left off. So this is how the WDT is associated with the counter.

Hope this helps