odd pic problem on 18f6723

[richardb]

Hi maybe someone con help me with this odd problem.

I've been using a 6723 recently and all's been fine except for one problem, I'm using port B.6 to drive a fet to turn on a relay on a board and all is ok just after i program the pic but if i cycle the power it wont work, I've tried pulling the output high with a resistor but the output seems to be driven low permanently.

ps

I've tried this with 2 different main pcb's
pic is on a 40pin dil header and i've tried 2 different 6723 pics in the same pcb without luck.
But if i replace the 6723 with a 4550 then everything works fine.


Any suggestions?

[richardb]

ok so i fixed the problem..... but it seems like a compiler bug

i removed all places in my code where i set the output low and

left the place where i set it high and the output still wouldn't come on.

but if i moved the portb.6 = 1 to just before the main code it would work.

[Jon Chandler]

One thing I found recently......

If you use a variable name as a port pin:

dim LED as PORTB.0


and then do something like:

LED = 1

LED = 0

You won't see any change on the port pin.

If you add a lin near the top of the program:

HIGH (LED)

or

LOW(LED)

the above works fine.

I believe the added HIGH or LOW command makes PORTB.0 (in this case) an output.

Jon

[rmteo]

Jon, have you tried:
dim LED as LATB.0

before using:
LED = 1
LED = 0