Problem with WHILE - WEND

[sayzer]

First:
Goto should not be used with "While" statement. Use "IF" instead.
ex:

IF Footsw=1 or Ready=1 then Goto Start

Second:
Your statement should have been as below.

While Footsw=1 or Ready=1
Goto start    'cant'be on the same line with While
Wend

[Russ Kincaid]

Thanks for the replies. I had tried IF - THEN but did not do that right either!

[mister_e]

1. Parenthesis are important in most case
2. I would never jump out of a WHILE statement using a GOTO. Using a flag or Validate the Conditions to get out of the WHILE/WEND loop is, IMHO, a better practice.

Could be also..

Start:
    LOW RENCA
    LOW EJECT
    While (FootSw=1) OR (Ready=1) : WEND

OR

Start:
    LOW RENCA
    LOW EJECT
    SpinHere: If (FootSw=1) OR (Ready=1) then SpinHere

You may notice that one method generate less code space than the other.

[Russ Kincaid]

Here is my problem: I tried the spinhere loop, it works but the following statements are a loop. I want the program to stay in the loop but as soon as either footsw or ready goes high, the program jumps back to the spinhere loop. I don't want it to do that. How do I do it?

[mister_e]

SpinHere:
    LOW RENCA
    LOW Eject
    While (FootSw=0) OR (Ready=0)    
          '
          '    Do your loop here
          '
          wend
    goto Spinhere

[Russ Kincaid]

I have not explained my problem properly: I want a momentary switch closure (footsw) to cause the program to jump to a loop (freq. I don't want it to jump out of the loop when the switch opens.

[Acetronics2]

Hi, Steve

Keep cool ... keep cool ...

Alain

Hi,Russ

Could you explain EXACTLY what you want to do ...

I mean : the switch closure lead to jump into the loop, OK ... but what happens if switch released ??? stay in the loop ??? go where ??? do you test your switch continuously after jumping off the loop ??? or just once at the beginning of your program ???

We're not at school ... no one will copy your project !!!!

Problem written is half the solution ....

Alain

[Russ Kincaid]

I want a momentary switch closure to jump to a loop and stay there, regardless of further action by the switch. Perhaps an interrupt is what I need? I don't exactly know how to do that, but will experiment. I prefer to use portb.5 for interrupt input, the data sheet says the RBIF flag will be set regardless of the state of the INTCON enable bit?