PortE problems (PIC18F4455)

[RubenR]

Hi there,

If got a little problem (but strange to me). I'm trying to use portE of my pic18F4455. Now i'm using it as an input, but later I also want to use it as an output.

The problem is that only pin RE3 look to work fine.

Here the code I'm using:

        Include "modedefs.bas" 
        
        DEFINE OSC 4
        E_0         VAR     WORD
        E_1         VAR     WORD
        E_2         VAR     WORD
        E_3         VAR     WORD
        TestLED     VAR     PORTC.6
        RS232TX     VAR     PORTD.2
       
Intro:
    ADCON0 = 7
    ADCON1 = 7
    ADCON2 = 7
    CMCON  = 7
    TRISC  = 255
    
    HIGH TestLED
    Pause 100
    LOW TestLED
    PAUSE 100
    HIGH TestLED
    Pause 100
    LOW TestLED
    
    SEROUT RS232TX,N9600, ["Start...",13,10]
    GOTO Main
    
Main:
      E_0 = PORTe.0
      E_1 = PORTe.1
      E_2 = PORTe.2
      E_3 = PORTe.3
      SEROUT RS232TX,N9600, ["E0=", #E_0, " E1=", #E_1, " E2=", #E_2, " E3=", #E_3 ,13,10]
      Pause 200

GOTO Main

In the serial output only the RE3-value changes from 1 to 0, when I switch the pin from high to low

Output:

E0=0 E1=0 E2=0 E3=1
E0=0 E1=0 E2=0 E3=0

What am I doing wrong?

[mister_e]

adcon1=$0F
is one of the setting that will work...

datasheet ....

[RubenR]

Thanks, I thought I'd tried everyting, but it works fine now.

[RubenR]

Now I would like to disable the USB-controller of this pic, because I don't need this feature and I have to use the input pins RC4 and RC5.
I've read the datasheet and I can disable USB by setting bit3 (USBEN) of the UCON register to zero. The problem is that it looks that PBP doesn't know the commands I want to use. I think i have to use assembly. I tried the following, but I get a warning.

ASM
MOVLW 0h
MOVWF UCON
ENDASM

Warning:
Found opcode in collumn 1. (MOVLW)
Found opcode in collumn 1. (MOVWF)

I think my assembly knowledge is very bad

[mister_e]

Reason is that there's no UCON register definition in the PIC18EXT.bas file

look at the end and add it like this

TXREG2	VAR	BYTE EXT
TXSTA	VAR	BYTE EXT
TXSTA1	VAR	BYTE EXT
TXSTA2	VAR	BYTE EXT
UCON    VAR	BYTE EXT <= here
VELRH	VAR	BYTE EXT
VELRL	VAR	BYTE EXT
WDTCON	VAR	BYTE EXT
WREG	VAR	BYTE EXT

hey!!! don't place the comment to the right

[Demon]

Hi Steve,

I also need to add UCON and UCFG for a PIC 18F4550. Adding the variables in the file mentionned above corrects the undefined error at compile time, but how do those variables get linked with the proper registers?

Robert