PIC 18f4680 DIGITAL INPUTS

[MegaADY]

Thank you very much Melanie for your support .

[MadAl]

Hi,

just ported a program from 16F877 to this PIC. And Port D refuses to act as an input.
I tried the following program snippet:

ECCP1CON=%00000000
TRISE.4=0
TRISD=%0001111

IF PORTD.2=1 THEN
HIGH beeper
PAUSE 1000
LOW beeper
ENDIF

I put a 1k resistor from Vdd (5V) to port D2. The beeper doesn't sound. When I change the conditional statement to "PORTD.2=0",then the beeper sounds, even with the resistor connected! I checked for shorts, and no there is no short from D2 to GND.
I also tried ports D1 and D3: same result...
For some reason ports D refuse to become input and stay output low.....

Another funny thing is that I use PortA0 as AD converter. If I connect 3V to this port, the PIC heats up like crazy (not so with the same PCB and 16F877)
When I put a 100k in series with this pin, the AD works OK and PIC doesn't heat up.
So also this pin acts as active low, even in AD mode....


Any ideas what more to try?

[MadAl]

The following lines solved the (first) problem:

CMCON7=0
ECCP1CON=%00000000
TRISE.4=0
TRISD=%0001111

Amazing that a simple "INPUT PORTD.2" doesn't do it.

I will study the datasheet on the CMCON stuff.

thanks

[MadAl]

Melanie,

I followed your register tutorial and ran into the following snag:

I use HSEROUT on port C6 (the hardware Tx pin) and all works fine.
However when I issue a SEROUT2 command on that pin, the pin remains silent (no activity on that pin using the oscilloscope). The very same SEROUT2 command on port A1 gives activity on the scope screen.
I assume the same applies to the SERIN2 on port C7.
What am I missing here?

[skimask]

I use HSEROUT on port C6 (the hardware Tx pin) and all works fine.
However when I issue a SEROUT2 command on that pin, the pin remains silent (no activity on that pin using the oscilloscope). The very same SEROUT2 command on port A1 gives activity on the scope screen.
I assume the same applies to the SERIN2 on port C7.
What am I missing here?

If the port is still set up to use the hardware serial port, SERIN/SEROUT won't work. The port has to be set up for normal, general purpose I/O to work with SERIN/SEROUT.

[MadAl]

Hi,

I thought about that. I removed the hardware serial defines at the start of the program, and the problem remains.
Or is there another way to disable HW serial?
Btw I tried the same with a 16F877 and also there the same issue exists.

[Bruce]

Try this;

DEFINE HSER_BAUD 9600

Main:
    HSEROUT ["HSER",13,10]
    PAUSE 500
    SEROUT2 PORTC.6,84,["WITH RCSTA.7=1",13,10]
    PAUSE 500
    RCSTA.7=0
    SEROUT2 PORTC.6,84,["WITH RCSTA.7=0",13,10]
    PAUSE 500
    RCSTA.7=1
    
    GOTO Main

You should get this;

HSER
WITH RCSTA.7=0
HSER
WITH RCSTA.7=0

With RCSTA.7 set the USART takes over these pins.