Do Loop

[skybox]

I have a project with a few relays and a 12 volt dc motor. The motor opens and closes a door based on a light and dark (LDR) The door has hall sensors to limit travel. For the most part everything works fine but every so often the door starts to open and then the program goes into a loop or crashes. I compiled the program with the watchdog timer off. Since this start happening I did some research and found that without the watchdog timer employed the program can be reset after a per-determined time period. Obviously, I need to turn watchdog on. However, I have a question about my code that may be contributing to the problem.

Below is a sample of a "DO Loop" I use:

If (Light = 1) and (DoorClosed = 0) then

Relay2 = 1
DO
Loop until DoorOpen = 0
Relay2 = 0

End if

Notice there is no statement after "DO". It goes immediately to the "loop until DoorOpen = 0." This does work but I'm wondering if this might be contributing to the problem. Is this a proper way of using the DO Loop? That is without a statement in between DO and Loop?

[longpole001]

i would not think its a problem , but you can always try using while wend loop see if changes the problem

while dooropen <> 0
wend

[spcw1234]

Using while wend is a better method, but nothing shown here should cause your problem. Can you share all of your code? I had a similar issue by not exiting a subroutine properly, the program worked for a while then would eventually crash. It took me a while to pin point it.

[skybox]

Shawn,

Thanks for the reply. I do have a question concerning your answer. In the PBP manual it states the "While...Wend" has been deprecated and to use the "DO...Loop" instead. I never completely trust manuals because most become outdated with code updates. As such, I'd very much appreciate an elaboration as to why I should use the "While...Wend' when the manual states otherwise.

Thanks

Skybox

[SteveB]

For what you are doing, you can also use this method:

WaitForDoor:
    IF DoorOpen <> 0 THEN WaitForDoor

[mister_e]

        WHILE DoorOpen : WEND
        '
        '       or
        Repeat : Until !DoorOpen
        '
        '       or        
SitAndSpin:  If DoorOpen then SitAndSpin
        '
        '       or        
        Do Until !DoorOpen : Loop
        '
        '       or        
        do : Loop WHILE DoorOpen

As far as I'm aware of, PBP take care of the WatchDog timer, so it shouldn't be an issue...

[spcw1234]

Shawn,

Thanks for the reply. I do have a question concerning your answer. In the PBP manual it states the "While...Wend" has been deprecated and to use the "DO...Loop" instead. I never completely trust manuals because most become outdated with code updates. As such, I'd very much appreciate an elaboration as to why I should use the "While...Wend' when the manual states otherwise.

Thanks

Skybox

I have found the while wend to always work, I know I had problems with the do loop, but that may have been something else causing the problem. Some of the other suggestions here look to be a better alternative to either of these anyways.

[Vett58]

I am not sure if this would help or not , but I did have problem with some simple code that I had included Do,Loop.
The code worked fine when it was compiled using PBP3.0 but it did not work if it was compiled by PBP2.50B , which I had on an older machine.
The problem was solved when I changed the Do,Loop section to GOTO , and then the result from both PBP3.0 and 2.50B worked flawlessly.