Thread: Help with LED program update :) (BEGINNER)

I'm a beginner, I have an Atmel STK500 AVR development board.

EDIT: I didn't explain what the code does, sorry :S When I press a button on the board, the corresponding LED lights up until I release the button!

I've manipulated code I found on the internet into this:

Code:

#include <avr/io.h>     // avr header file for IO ports
int main(void){
    DDRA = 0x00;    // set PORTA for input
    DDRB = 0xFF;    // set PORTB for output
    PORTB = 0x00;  // turn ON all LEDs initially
    
    while(1){
        PORTB = PINA;
    }
    return 1;
}

That code works fine. I wanted to try to write the same thing another way. Here's what I have so far:

Code:

#include <avr/io.h>     // avr header file for IO ports


int main(void){
    DDRA = 0x00;    // set PORTA for input
    DDRB = 0xFF;    // set PORTB for output
    PORTB = 0x00;  // turn ON all LEDs initially
    
    if(PORTA == 0){
        PORTB = 0;
    }        
        else PORTB = 1;
    return 1;
}

This code builds and compiles but when I run the program on my development board the LEDs just stay lit and the buttons do nothing. I want to achieve the same results as I do with the first code, just written differently. I also noticed that my second code doesn't have a loop, does it need one? Any help? Thank you!

This is the sort of programming that I'd like to get into soon. Looks like a lot of fun.


AVR 8- and 32-bit Microcontrollers- Atmel Corporation

Originally Posted by Matticus

Regarding the second bit of code in your first post; did you try putting *that* code into a constant loop?

@cfanatic: In my opinion, if you have no MCU experience, then PIC (Microchip) microcontrollers are the best to start with. They are (again, in my opinion) the most "friendly" to work with.

From working as a Teaching Assistant I have learned the below PIC information.

When working with PIC Chips it is very important to remember to hookup power and ground.
I have had students who missed either power or the ground connections and the PIC chip almost worked right.
So, if the PIC project almost runs right; confirm that you have a good power and ground DO NOT assume it is good.

Tim S.