Simple question about While Wend...

[dbachman]

I have been trying for a while to get this simple code to work. Can someone tell me why it won't?

Thanks, Don

while porta.2 <> 0
wend
high portb.6

porta.2 has pullup installed but led on portb.6 always lights....... isn't it supposed to sit there until porta.2 becomes low?

[Normnet]

"<>0" is the equivalent of "= 1" for a hi low read.


Norm

[dbachman]

Right.... while pin 2 is at a high state shouldn't the program stay in the while/wend loop until it goes low and then jump out and turn on the LED?

[Normnet]

Right.... while pin 2 is at a high state shouldn't the program stay in the while/wend loop until it goes low and then jump out and turn on the LED?

Yes

Try if not already:
Read a PortB pin in place of portA to avoid config errors.
Initialize Low portB.6
Is the read pin an input?


Norm

[dbachman]

this is the code..

Trisa = 1
Trisb = %00100000
portb = 0
while portb.5 = 1
wend
high portb.4

[Normnet]

Try adding some debugs to see if you can find where the breakdown occurs:

Trisa = 1
 Trisb = %00100000
 portb = 0

if portb.5 = 1 then
SerOut2 cSEROUT_PIN,cBAUD,["PRE HI",13]
else  
SerOut2 cSEROUT_PIN,cBAUD,["PRE LOW",13]
endif
  
 while portb.5 = 1

if portb.5 = 1 then
SerOut2 cSEROUT_PIN,cBAUD,["LOOP HI",13]
else  
SerOut2 cSEROUT_PIN,cBAUD,["LOOP LOW",13]
endif

 wend

if portb.5 = 1 then
SerOut2 cSEROUT_PIN,cBAUD,["AFT HI",13]
else  
SerOut2 cSEROUT_PIN,cBAUD,["AFT LOW",13]
endif

 high portb.4

Norm

[Tabsoft]

What PIC MCU are you using?

Should you be using LATB register instead of PORTB register for your High and Low statements?
Read modify write may be an issue.