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RTC loses its way

 
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njepsen

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Joined: 13 Aug 2007
Posts: 412

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PostPosted: Fri Nov 20, 2015 1:47 am    Post subject: RTC loses its way Reply with quote

I have a problem with a RTC which from time to time, (no pun intended) suddenly loses 6 moths if I run a particular subroutine.
Here is the code snippets which works OK, and has been reliable for a year or more.


Code:


'*******************************************************************************
$regfile = "m1284pdef.dat"                                  'my processor
$crystal = 9830400                                          'system crystal

$framesize = 800                                            ' Located at top of 16k of SRAM
$hwstack = 250                                              '
$swstack = 250                                              '
$frameprotect = 1
'various dim statements are here


'we want to set up counter 1 to toggle 1x per sec
Dim Timer1preset As Long                                    'therefor prescale = 65536 - 39062.5 = 26473
Config Timer1 = timer , Prescale = 1024                 'counts 9830400/1024 = 9600 per sec
                                                                          'timer preset = 65536 - 9600 = 55936
Config Clock = User
Config Date = Dmy , Separator = /
Timer1preset = 55936    

$baud = 9600
Open "com1:" For Binary As #3                                
Config Serialin = Buffered , Size = 200 , Cts = Pind.4 , Rts = Pind.7 , Threshold_full = 30 , Threshold_empty = 30
Config Serialout = Buffered , Size = 250

 '*************************************************************
'main loop is here
do
   code
   call housekeeping()  ' this gets called often
code
code

loop


'*************************************************************

sub housekeeping()

    'This sub increments the local RTC
    'No interrupts are used
    'The 'A compare' is set to zero and the compare flag  tifr1.OCF1A
    'goes high when counter1 = 0, which happens every 1 sec
    'Sub takes about 5uSec

   ocr1aH = 0                                               'set compare hi byte to 0
   ocr1al = 0                                               'set compare lo byte to 0


   if tifr1.OCF1A = 1 then                                  'Timer Int Flag Register. Compare with 0 is true
      timer1 = 55936
      tifr1.OCF1A = 1                                       'reset bit 1. see pg140 of atmega 1284 data sheet
      if mytimeoutb_sec > 0 then Decr mytimeoutb_sec        '1 sec used in timer loops
      incr local_sec
      time$ = time(local_sec)                               'calculate time & update RTC This could be moved also
    '  date$ = date(local_sec)                               'calculate date & update RTC  moved to main loop
   end if
 end sub

'*******************************************************************
 


This next piece of code looks for 32 numbers from a noise meter, which is on a ser port #3. If the loop runs once,
then there is no problem.
BUT if the loop runs 5 times because the noise meter is turned off for example,
then during this loop, the date$ and time$ values go back to February 2015.

Code:


      #If enable_thirds = 1
        Retries = 0
        msg_id = 99
        do
            incr retries
            call timedelay_ms(100)
            Print #3 , "XC1;"                               'meter preset
            call timedelay_ms(100)
            Print #3 , "XW2;"                              'meter preset
            call timedelay_ms(100)
            Print #3 , "BL8 , 32;"                          'ask meter for 32 1/3rd octave values
            call receive_meter_RS232(32)

        Loop Until Retries > 5 Or Msg_id = 0
      #endif

'*******************************************************************************
 


here are the two subs that are called from the problem sub.
Code:


'***********************************************
Sub Timedelay_ms(byval Mydelay As Integer)
 'delay in ms
 'does not need timer1
   local dly as integer
   dly = 0
   While dly < Mydelay
      call housekeeping()
      waitms 1
      Incr dly
      Reset Watchdog
   Wend
End Sub

'******************************************************************************

'*******************************************************************************
   sub Receive_meter_RS232(byval targetcommacountint as integer)

   Mytimeoutb_sec = 20                                      '20 secs
   Msg_id = 99
   Commacounti = 0
   charcount = Temph                                                'restore pointer

 do

      rxbyte = inkey(#3)
      If Rxbyte = 32 Then Rxbyte = 0
      If Rxbyte = 10 Then Rxbyte = 0
      If Rxbyte = 13 Then
         Rxbyte = 44
         Incr Commacounti
      End If
      If Rxbyte <> 0 Then                  
                   
         Incr Charcount                                     'used when writing to sd card
         Bigbuffer(charcount) = Rxbyte               'store my data in  buffer

      End If

      Reset Watchdog
      call housekeeping()
      If Commacounti = Targetcommacountint Then
            Msg_id = 0
            Print #1 , ""
            Print #1 , ">> expected " ; Targetcommacountint ; ",got " ; Commacounti       'print target & actual
            clearmeter
            exit sub                    'this is the normal exit from this sub
      end if

   Loop Until Mytimeoutb_sec = 0
      tempstr1 = ">> wrong comma count.Target =  " + str(Targetcommacountint) + ",got " + str(Commacounti)
      print #1 , tempstr1
     
      'back up the pointer
      while charcount > temph
             decr Charcount
      wend
                                                   '


end sub

 '******************************************************************************


(BASCOM-AVR version : 2.0.7.7 , Latest : 2.0.7.8 )

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enniom

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Joined: 20 Oct 2009
Posts: 474

PostPosted: Fri Nov 20, 2015 3:48 am    Post subject: Reply with quote

1. Can you be sure that Charcount is always within the dimensioned value of Bigbuffer?

2. What is clearmeter?
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njepsen

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Joined: 13 Aug 2007
Posts: 412

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PostPosted: Fri Nov 20, 2015 4:02 am    Post subject: Reply with quote

Bigbuffer is dimensioned to 10,000 bytes and elsewhere in the code, its size is checked
& the pointer reset to 1. (this has never happened )

here is clearmeter
Code:


 '******************************************************************************
sub clearmeter()                                            'clear out meter tx buffer
   'clear meter serial port buffer
   mytimeoutb_sec = 3
   Do

      Rxbyte = Inkey(#3)
      Print #1 , "W" ;
      Reset Watchdog
      call timedelay_ms(2)
   Loop Until Ischarwaiting(#3) = 0 or mytimeoutb_sec = 0
end sub


'******************************************************************************

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enniom

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Joined: 20 Oct 2009
Posts: 474

PostPosted: Fri Nov 20, 2015 4:39 am    Post subject: Reply with quote

Only other thought.

Code:
while charcount > temph
              decr Charcount
       wend


Is it possible that this can assign a value of 0 or roll-under to 65535 (I assume Charcount is a Word to accommodate the 10,000-byte buffer size)?
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MWS

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Joined: 22 Aug 2009
Posts: 1813

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PostPosted: Fri Nov 20, 2015 7:17 am    Post subject: Reply with quote

enniom wrote:
Code:
while charcount > temph
              decr Charcount
       wend

Is it possible that this can assign a value of 0 or roll-under to 65535 (I assume Charcount is a Word to accommodate the 10,000-byte buffer size)?

That's only an odd and cycle-intensive way of writing:
Code:
charcount = temph
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enniom

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Joined: 20 Oct 2009
Posts: 474

PostPosted: Fri Nov 20, 2015 1:02 pm    Post subject: Reply with quote

Hi Neil,

You use $Frameprotect.

Are you passing variables in subroutines used in ISRs?

If so, could these be overrunning the $Framesize?
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njepsen

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Joined: 13 Aug 2007
Posts: 412

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PostPosted: Wed Nov 25, 2015 3:39 am    Post subject: Reply with quote

Hi enniom,
Thanks for taking time to look at this. I think You mean - am I passing variables in subs that are also used in ISRs?
The answer is no.
I only have 3 IRSs. Timer rollover for T0,T1 and T3, and the serial ports. I have included the timer ISRs below.
T0 simply flashes a LED, T2 is the RTC, and T3 calls a sub that checks a flag.

The problem with this bug is I can wallpaper over it so it doesnt happen, but I dont know what is causing it.

Code:

 '*****************************************************************************
sub timer3overflow()
      'T3 rolls over every 5 seconds
      'ttrn is checked every 30 seconds
       timer3 = 17536                                           '65536 - 9600x5
      call check TTRN                                            ' time to read noise

end sub
 '***********************************************
sub Timer0overflow()

   'called 37 x per second
   'flashes LED once per sec
   $asm

       push r24                                             ;save r24
       in r24, sreg                                         ;r24<-sreg
       push r24                                             ;save status register to stack
       lds r24, {btimer0}                                   ;load direct
       inc r24
       cpi r24,37                                           ;compare
       brlo timer0overflo                                       ;br if r24 < 37
       clr r24                                              ;clear r24
       sbi heartbeat_pin,heartbeat_bit                       ; write 1 to pin = toggle led
   timer0overflo:
       sts {btimer0},r24                      ;store btimer0 <- r24
       pop r24
       out sreg , r24                                       'get Sregister back
       pop r24

   $end asm
end sub

'********************************************************************************

 '*****************************************************************************
sub Check_ttrn()
   'is it TTRN  (time to read noise).
   'This sub called once every 5 sec under interrupt of timer3
   'Dn5 lets it happen only once per 15 min
   'TTRN is latched in this sub and unlatched when data is sent
  'dn5 = a semiphore bit called 'done5'



   if dn5 = 0 then
            If _min = 0 Or _min = 15 Or _min = 30 Or _min = 45 Then
               Dn5 = 1
               Ttrn = 1                                     'time to read noise
               Print #1 , ">> time to read noise"
            End If
   else
            If _min <> 0 and _min <> 15 and _min <> 30 and _min <> 45 and ttrn = 0 Then
               Dn5 = 0

            end if

   end if

end sub

 '*****************************************************************************

*

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