Basic code to switch LED for PIC18f4550 C18 not working

Question

Ok, I'm sure it's something stupid but this is probably the 20th variant of this code and I can't get it figured out. I simply want a (debounced) switch to trigger an LED on the PIC18f4550. Should I be using a different port for the switch? Here's my code:

void main(void) 
{

    TRISBbits.TRISB0 = 1;    //switch input
    TRISBbits.TRISB3 = 0;    // LED output
    PORTBbits.RB3 = 0;       // make LED low by default
    TRISEbits.TRISE2 = 1;    // alternate switch input


    while (1) {                       // doesn't work for some reason
        if (PORTEbits.RE2 == 1) {
            LATBbits.LATB3 == 1;
            }
        else LATBbits.LATB3 == 0;
    } 
}

Tried to post the config code but it screwed up the formatting here.

---

EDIT: sorry for the ugly formatting, but here are the config settings. Had to change some things to keep the formatting from getting weird.

include stdio.h    
include stdlib.h    
include p18f4550.h    
include delays.h    

// chip config     ////////////////////////////////////////////////////////////////////////////////////

pragma config PLLDIV = 5             
pragma config CPUDIV = OSC1_PLL2    
pragma config USBDIV = 2        

                               // internal clock, pin #14 (RA6) as I/O pin, pin #13 unused,    
pragma config FOSC = INTOSCIO_EC    // if OSCCON is left as default clock speed will be 1Mhz    

            // now the other less confusing options . . .    
pragma config FCMEN = OFF       
pragma config IESO = OFF        
pragma config PWRT = OFF        
pragma config BOR = OFF     
pragma config BORV = 3      
pragma config VREGEN = OFF  
pragma config WDT = OFF     
pragma config WDTPS = 32768     
pragma config CCP2MX = ON       
pragma config PBADEN = OFF      
pragma config LPT1OSC = OFF         
pragma config MCLRE = ON            
pragma config STVREN = ON       
pragma config LVP = OFF     
pragma config ICPRT = OFF       
pragma config XINST = OFF       
pragma config DEBUG = OFF

Answer 1

You didn't show the external circuit, but if you just have a switch connected between the input pin and ground (or power), then that's not enough. That will drive the pin one way when the switch is closed, but leave it floating when open. There is no guarantee what state it will be in when left floating. To fix this, tie a pullup or pulldown to the pin that pulls causes it to go to the opposite polarity when the switch is open.

For example, tie the switch between the pin and ground, and then the pullup between the pin and Vdd. use 1 - 10 kΩ for the pullup.

Some pins of that PIC can be configured for internal pullups. RB4-RB7 can but possibly others on that PIC (your job to check the datasheet). If you enable the internal pullup, then the only external part you need is the switch between the pin and ground.

 

Answer 2

The pins you are using are also analogue inputs, so you need to make sure these are off. Also turning the comparators off is a good idea, in case you want to use RA0 to RA5.

The code is:

CMCON = 0x07;
ADCON1 = 0x0F;

Read the section on the IO Ports and the ADC, it tells you all you need to know.