Do While

[Stefano Bonomi]

I've just tried a never ending loop using:

Do while true
.
Instructions
.
Loop

It doesn't work at all...the solution is to set a variable to one and use it for testing purpose like this:

Forever=1

do while Forever=1
.
Instructions
.
loop

Any idea ?

[Nobody/Anonymous]

I think that your piece of code:
Do while true
.
Instructions
.
Loop

is not correct, simply due to the GCBASIC syntax.

vinas

[Nobody/Anonymous]

The Do While Loop compiles and runs fine.  Look at your Pic initialization and instructions as these are suspect.  Are you getting compilation errors?

Kent

[Hugh Considine]

That looks like a bug in GCBASIC. STATUS.Z isn't set or cleared properly, so the if used to check if the loop should be run doesn't work. I'll fix this in the next version of GCBASIC.

The "while true" is not necessary. This code will generate more efficient assembly:

do
.
Instructions
.
loop

[Stefano Bonomi]

Hi Vinas, the sintax for the Do While loop is correct...repeat all steps between the Do While instruction and the Loop instruction, while the condition remain true.
Kent, like said in my first post, the code works if I use a varialbe equal to one for Do While testing purpose.
Anyway Hugh, what you suggested (do....loop) works perfectly.

Here is the code:

'Software PWM
'PORTC.2 drive a LED
'this loop do a simple PWM
'with variable duty cycle
'causing a progressive LED illumination
#chip 16F690,4 
#config _INTRC_OSC_NOCLKOUT, _WDT_OFF,_PWRTE_OFF,_MCLRE_OFF,_CP_OFF, _BOR_OFF, _IESO_OFF,_FCMEN_OFF 
#Define LED1 PORTC.2
ANSEL=0
Forever=1
cont=0
level=0
i=0
'    Main routine
DIR PORTC b'00000000' 'PORTC as output
PORTC = b'00000000'   'PORTC to 0
do   
    if cont>level then SET LED1 OFF
    if cont<=level then SET LED1 ON
    cont=cont+1
    i=i+1
        if i=200 then
         level=level+1
         i=0
        end if
loop