Increment a Byte

[savnik]

I have a simple problem but i don't can solve.

pwr var byte

If up = 1 Then
       PAUSE 50
       pwr = pwr + 1                              
       If pwr >= 255 Then pwr = 255                 
Endif

If pwr >= 255 always go to 0 and no to 255.Why happen this?

[aratti]

If pwr >= 255 always go to 0 and no to 255.Why happen this?

Since a byte can count up to 255 max when you add 1 to 255 the byte overflow and start from zero again (it cannot be 256).

If you want to keep your variable pwr at 255 then you can skip the add command, or you must use a word variable.

pwr var byte

If up = 1 Then
       PAUSE 50
    If pwr = 255 Then Skip00
 pwr = pwr + 1                              
 Skip00:                       
Endif

Al.

[savnik]

Thank you. It is work.
I don't want use word variable , because pwr is for duty of HPWM.

[Acetronics2]

Hi, Savnlik

You just can use :

For I = 1 to 255

PAUSE 50
HPWM 1,I,1000              ' The reason of your loop ( BTW ...). 1000 is pwm freq.

NEXT I

or ...

DO

I = I + 1

....

While I < 255

For limiting Numbers:

I = J MIN 255  ' I is the smaller ( MIN ) number between J and 255 ...

Alain

[HenrikOlsson]

Or,

If Pwr > 254 then pwr = 255

[savnik]

Or,

If Pwr > 254 then pwr = 255

I had test and not work.Because next have count 255 + 1 = 256

[savnik]

Hi, Savnlik

You just can use :

For I = 1 to 255

PAUSE 50
HPWM 1,I,1000              ' The reason of your loop ( BTW ...). 1000 is pwm freq.

NEXT I

or ...

DO

I = I + 1

....

While I < 255

For limiting Numbers:

I = J MIN 255  ' I is the smaller ( MIN ) number between J and 255 ...

Alain

I change the duty manually with two buton's (up and down)

[HenrikOlsson]

I had test and not work.Because next have count 255 + 1 = 256

Ouch, yes of course... my mistake, sorry.

[savnik]

Ouch, yes of course... my mistake, sorry.

No problem.
aratti code solve my problem.