touble with a time calculation

[longpole001]

well after a few more tests that did not work well , yes , when you enter a event period of 10sec for the event time or 1 min or 1 hour , 1day then code answers earlier will allow for the <0 error when it roles over , but its does not when you combine Event set time for say 1 m 10 sec

so lets start again
sounds simple but its giving me a problem
GOAL
------
the count up elapsed base timer is counting up from 0 , when the set time values are => then time set for the event the Overtime clock is enabled starts counting up to show the time past the set time

code references
---------------
Base Elapsed timer is set to count up = EL1
Overtime Clock = EL2
Event1_OT_xxx = Time set duration for event


EL1 has the standard time duration if statements enabled so that sec = 60 then sec = 0 , min = min +1 , same for hour , day 0 then 1 min , etc etc for counting up

'-------  Event overrun timer 1-------- 
     if EL1_Days => Event1_OT_Day    and EL1_hOURS => Event1_OT_Hour  and _
        EL1_Minutes => Event1_OT_Min and EL1_Seconds => Event1_OT_Sec and _
        EL1_100th => Event1_OT_100th then EL2_Enable = 1
     
    if  Event1_OT_Day = 0 and Event1_OT_hour  = 0 and Event1_OT_Min = 0 and _  ' if all values are 0 , then dont enable the overrun timer 
        Event1_OT_sec = 0 and Event1_OT_100th = 0 then  EL2_Enable = 0
  
     if EL2_Enable = 1 THEN     ;  EL2 = EL1 current values - set overrun value  
        EL2_Days    = EL1_Days    - Event1_OT_Day  
        EL2_Hours   = EL1_Hours   - Event1_OT_hour
        EL2_Minutes = EL1_Minutes - Event1_OT_Min 
        EL2_Seconds = EL1_Seconds - Event1_OT_sec
        EL2_100th   = EL1_100TH   - Event1_OT_100th
     endif

addings code to allow for <0 error ( EL1_Seconds - Event1_OT_sec) - this occurs when secs role over 1min but the work arround is not working when combined with sat set times of 1min 10 sec


any further sugestions

[EarlyBird2]

     if EL2_Enable = 1 THEN     ;  EL2 = EL1 current values - set overrun value  

       EL2_100th   = EL1_100TH   - Event1_OT_100th+100
        if EL2_100th<100 then 
          EL1_Seconds=EL1_Seconds-1
       Else
         EL2_100th=EL2_100th-100
      endif

    EL2_Seconds = EL1_Seconds - Event1_OT_sec+60
      if EL2_Seconds<60 then 
        EL1_Minutes=EL1_Minutes-1
     else
       EL2_Seconds =EL2_Seconds -60
     endif

       EL2_Minutes = EL1_Minutes - Event1_OT_Min +60
     if EL2_Minutes<60 then
       EL1_Hours=EL1_Hours-1
     else
       EL2_Minutes =EL2_Minutes -60
     endif

       EL2_Hours   = EL1_Hours   - Event1_OT_hour+24
     if EL2_Hours<24 then
        EL1_Days=EL1_Days-1
     else
       EL2_Hours   =EL2_Hours   -24
     endif

  EL2_Days    = EL1_Days    - Event1_OT_Day  
       
endif

Just something to try

[richard]

steve has the right idea for the math but since el1/el2 vars can be updated via the isr at any time during the calcs the results will vary.

statisticly it will fail about 4-5 times per hundred calcs based on :-
I think chances of failure are 1/60+1/60+1/100+1/24 I might be wrong about the stats

[EarlyBird2]

If isr affects EL1 vars create Temp_EL1 vars at the start of the routine and use these for the calculation.

[richard]

won't work . the isr can change the values as u copy them to the temp vars ,been there done that

[EarlyBird2]

Ok some problems do not have an answer.

Bye

[richard]

only solution I know is to disable isr and copy vars to a buffer then enable isr and then perform calcs on the buffered data.
it may mean the odd lost interrupt / whats worse incorrect calcs or missed ints
only the designer can make that call .