Time limit while waiting for input ?

[Sam]

Hi Richard,

I've been studying your code, (again) I haven't tried to compile the items added in red below as I'm on a different PC right now. I just posted a small part of it for learning.

Can you tell me if I'm on the right track with how I've added it ?

So after 100 seconds, if the limit hasn't sent a low, limup pin will still go low ?

Thanks !

maxrun con 2000  ;  2000 = 100 sec
RUN_COUNT VAR word


moveup:
high blue
pause 500
low blue
while limup = 1
high up
wend
IF   RUN_COUNT  THEN    ;should the motion continue ?
             RUN_COUNT = RUN_COUNT -1
ENDIF
if limup = 0 then
low up
goto run
else
goto moveup
endif

[richard]

hi sam

I will make some assumptions here
blue is a led that should flash when moving
up enables movement
limup stops movement when low


this is the movement loop / the only way it stops is if limup = 0

while limup = 1
high up
wend

its not what you want

try some thing like this

moveup:
high blue   ;  led on 
high up     ;  motor on
RUN_COUNT=200  ; set time limit 200*500mS  ie 100 sec
while (limup = 1 ) && ( RUN_COUNT>0) ; do this till time runs out or limit sw trippe
pause 500
toggle blue  ; flash led
RUN_COUNT = RUN_COUNT -1 
wend   ; all done 
low blue       
low up

[Sam]

Richard, you're awesome ! thanks very much !

This morning is the first chance I've had to try it without constant interruption. I must have done something a little different because it wouldn't work until I added...

moveup:
high blue ; led on
high up ; motor on
RUN_COUNT=200 ; set time limit 200*500mS ie 100 sec
while (limup = 1 ) && ( RUN_COUNT>0) ; do this till time runs out or limit sw trippe
pause 500
toggle blue ; flash led
RUN_COUNT = RUN_COUNT -1
wend ; all done
IF limup = 0 OR RUN_COUNT =>0 THEN
low blue
low up
ENDIF

Not sure why it doesn't work right without the ">0" but in any case, it's working great. Thanks again !!

[richard]

I have some doubts about your modification, perhaps you have some noise entering the system, or the limit switch is "bouncing"

IF limup = 0 OR RUN_COUNT =>0 THEN
low blue
low up
ENDIF

firstly operator precedence make this If test dodgy, parentheses ensure correct result
IF (limup = 0 ) OR (RUN_COUNT =>0) THEN
secondly

RUN_COUNT =>0

since pbp vars are unsigned , this will always be true it can only be 0 or greater
since the run_count test always tests true the if statement is always true

thirdly
the while loop will only exit if limup is 0 or run_count is 0 , the statement is or should be redundant