PIC18F452 prototype questions/problems....

[JS]

I just had some PIC18F452 boards made up and I've started playing with some
programming.

First off... I had breadboarded a DIP (PIC18F452-I/P) circuit and am now
using a PLCC package chip (PIC18F452-E/L).

I'm programming using a BASIC interpreter for ease of programming right
now... but this example would have worked just fine on my DIP package
prototype.

Driving RD2 high on also turns on RD4. After executing a pause, both will
turn off. Driving RD4 high also turns on RD2. RB2 and RB4 do the exact
same thing. I've tried three of my prototype boards with the same results.
I've checked the board traces and the two pins are not connected together
outside of the controller. Is this a software issue or am I stuck with a
hardware work-around (using another pin)?

My other problem is my own stupidity for not checking this first on the DIP
package chip, but RA0-3 and RA5 are TTL inputs and RA4 is a CMOS-level
Schmitt input. I have no switching on the TTL inputs. My circuit has 12V
going first through a 10K resistor and then to the port. The port is also
connected to the collector of a standard switching NPN transistor, which can
pull the pin low. Reading the pin during operation, I have approximately
5.7V present when no signal is applied to the base of the transistor and
0.18 present when the transistor is biased. This isn't enough to cause the
chip to respond to a change in signal. On the ST input, I have 12V with no
transistor bias and 0.18V with transistor bias in the same circuit, and this
works just fine. Since I've just had these boards manufactured, I'm
guessing I'm SOL, but if anyone can explain the cause and a possible
solution, it would be most appreciated.

Sorry for the newbie-style questions.

JS

 

[JS]

Ahh... sweet stupidity....

My RB2-RB4 problem was outside wiring shorted out and pulling both pins to
the same potential and low. My RA input problem was due to not setting
ADCON1 to allow for digital inputs.

Live and learn I suppose.

JS