How to Pause the process for 45 minutes?

Camaney · 2009-06-11 04:46

I am using the latest version of SX/B with SX28 chips.

I am trying to create an alert of blinking LEDs every 45 minutes, but so far I haven't been able to PAUSE for that amount of time.

I am using the following comand:
PAUSE 2700000
based on 1000 = one second.

Can someone tell me what I am doing wrong?
Thanks.

RS_Jim · 2009-06-11 05:01

I believe that pause only accepts an argument of 65535.· Try using the Sub Delay_MS which encapsulates pause into a single subroutine.· Each call to Delay_MS can be a word representing a minuite for example Delay_MS 60000 would delay 60 seconds. A for next loop of 0 to 45 calls to Delay_MS 60000 would net you a 45 minute delay.

RS_JIM

John R. · 2009-06-11 14:36

Keep in mind that anything over "seconds" is an eternity in time, at least for the microprocessor. Normally, you would not have a processor just "waiting" for that long, but it would often times either be doing something else, or waiting (looking) for "override" inputs.

An alternative to the loops RS Jim mentioned, another way to do this is to set a variable to the current clock count + the number of ticks you need for your "delay" time. Then have a loop that does your other stuff, or checks for inputs, etc., and part of that loop does a compare to see if the count is >= your setting. If it is, do your thing, if not, repeat the loop.

I'm not an expert by any means, but you may also be able to look at the "sleep" function. Is there a way you could externally trigger a "wake up call" (maybe a 555 timer).

Another possibility is to incorporate a real time clock (RTC), and do a comparison based on the actual time.

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John R.
Click here to see my Nomad Build Log

Bean · 2009-06-11 16:41

Camaney,
If you want to minimize power. Then you could use SLEEP with a WATCHDOG wakeup.

Basically, set the watchdog to it's maximum timeout (about 2.3 Seconds). When the program wakes-up it will increament a counter. When the counter reaches 1174 (45*60 / 2.3), then blink the LEDs.

DEVICE SX28, TURBO, STACKX, OPTIONX, OSC4MHZ, WATCHDOG
' NOTE you will not be able to debug this program because of the watchdog
 
IRC_CAL IRC_4MHZ
 
FREQ 4_000_000
 
' Enable pullups for unused I/O pins
UnusedRA PIN RA INPUT PULLUP
UnusedRB PIN RB INPUT PULLUP
UnusedRC PIN RC INPUT PULLUP
 
LED      PIN RB.0
 
WAITCNT  CON 10 ' in 2.3Sec units, 1174 = 45 MINUTES
 
cntr     VAR WORD
 
Program Start NOSTARTUP ' NOSTARTUP is important so the counter doesn't get zeroed
 
Start:
  IF _TO = 1 THEN
    ' No timeout, must be power-up
    OPTION = %11111111 ' watchdog prescaler set to 1:128 or about 2.3sec
    cntr = 0
    SLEEP
  ENDIF
  INC cntr
  IF cntr >= WAITCNT THEN
    OUTPUT LED
    FOR cntr = 1 TO 10
      RESETWDT
      LED = 1
      PAUSE 100
      LED = 0
      PAUSE 100
    NEXT
    cntr = 0
  ENDIF
  SLEEP  
END

Bean.

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There is a fine line between arrogance and confidence. Make sure you don't cross it...

Post Edited (Bean (Hitt Consulting)) : 6/11/2009 5:22:51 PM GMT

Camaney · 2009-06-12 01:18

Thanks all of you guys, but since I want this to be run off batteries I am leaning towards saving power.

Bean, I tried your code but when I run it tells me that _TO is not defined.

Any thoughts?

Thanks again.

Bean · 2009-06-12 01:56

Camaney,
· Make sure you have the latest version of the compiler.
· You can get it from here http://forums.parallax.com/showthread.php?p=780347
· Download the zip file, extract the files and copy them to C:\Program Files\Parallax Inc\SX-Key v3.2.92\Compilers\SXB

· Overwrite the existing files when asked.

Bean

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There is a fine line between arrogance and confidence. Make sure you don't cross it...

Post Edited (Bean (Hitt Consulting)) : 6/12/2009 2:01:27 AM GMT

Camaney · 2009-06-13 00:16

It's working, thanks.

For the sake of practicing and learning I also Tried RS_Jim suggestion and it did worked too. Thanks.
I also wanted to try John R. suggestion but I am not that knowledgeable yet; '...set a variable to the current clock count + the number of ticks you need for your "delay" time.'

Thank you all for your input, as I progress in my learning curve I am sure I will ask you again for help.

Bean · 2009-06-13 01:38

If you want to save battery life, you could run the SX as slow as 32Khz and/or from a lower voltage.

This will NOT change the watchdog timeout because the watchdog runs from it's own oscillator.

Bean.

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There is a fine line between arrogance and confidence. Make sure you don't cross it...

·

Camaney · 2009-06-14 12:46

Thanks for tip Bean, I made the change.

Camaney · 2009-06-14 15:41

I am still playing with this little project, now I am researching on how I can use potentiometer, read its value and use it for my WaitTimer, this way I can set up the alarm to wait for 15', 30, 45' or 60 minutes.
Ideas are welcome.
Thanks.

5ms? · 2009-06-14 20:54

What about this.


' -------------------------------------------------------------------------
' Variables
' -------------------------------------------------------------------------
MilliSeconds                VAR    Byte
HundredthsOfSeconds   VAR    Byte
TenthsOfSeconds            VAR    Byte
Seconds                     VAR    Byte
Minute                       VAR    Byte
Hours                            VAR    Byte
Days                         VAR    Byte
Weeks                       VAR    Byte


 -------------------------------------------------------------------------
' Subroutine Declarations
' -------------------------------------------------------------------------

Update_Clock SUB 0

' -------------------------------------------------------------------------
' Program Code
' -------------------------------------------------------------------------

Start:
  ' initialization code here

Main:
  Update_Clock
 GOTO Main



Update_Clock:
  INC MilliSeconds
  IF MilliSeconds = 10 THEN
     MilliSeconds = 0
     INC HundredthsOfSeconds
    IF HundredthsOfSeconds = 10 THEN
       HundredthsOfSeconds = 0
       INC TenthsOfSeconds
      IF TenthsOfSeconds = 10 THEN
         TenthsOfSeconds = 0
         INC Seconds
        IF Seconds = 61 THEN
           Seconds  = 0
           INC Minute
          IF Minute = 61 THEN
             Minute = 0
             INC Hours
            IF Hours = 25 THEN    
               Hours = 1
               INC Days
              IF Days = 8 THEN    
                 Days = 0
                 INC Weeks
               IF Weeks = 52 THEN
                  Weeks = 0     
              ENDIF            
             ENDIF        
           ENDIF        
          ENDIF
        ENDIF
      ENDIF 
    ENDIF 
  ENDIF
   RETURN

Something to think about anyway.

Hope it helps.

How to Pause the process for 45 minutes?

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