Re: [avr-gcc-list] Newbie - should this work?

[Christoph Plattner]

In principal, I don't think your code is correct !

All the other answers have not dealt with that, why ???

PORTD and DDRD are defines to registers numbers.

I think you have to use inp() and outp() or do a memory
access with `* (unsigned char *) <addr> = xxx'


example (which works):

    outp(0xff, DDRB);
    outp(0x00, PORTB);


Bye
Christoph P.

Josh Thompson wrote:
> Hi,
>
> I'm new at using working with embedded systems.  I am fairly familiar
> with using gcc under Linux.  I am using an ATmega128, avr-gcc, and usip
> with a ByteBlaster programmer.  uisp says it detects the chip and then
> loads the code into flash.  I can dump the code and get the same thing
> that I uploaded; so, I think this part is working okay.  Here is my code:
>
> main.c:-------------------------
> #include <io.h>
>
> int main() {
>    DDRD = 0xff;
>    PORTD = 0X00;
> }
> -------------------------------
>
>
> Makefile:----------------------
> all: main
>
> main: main.c
>    avr-gcc -D__AVR_ATmega128__ main.c -o main
>    avr-objcopy --output-target=srec main main.srec
> -------------------------------
>
>
> These are the steps I am taking:
>
> ./uisp -dprog=abb -dlpt=/dev/parport0 --upload if=main.srec
>
> after this, I disconnect the programmer cable
> disconnect power
> reconnect power
>
> At this point, I would expect to read 0 volts on the PORTD pins, but I
> am reading 1.5 volts.
>
> Should this work?  Am I following the right steps?
>
> I have also tried it with 'PORTD = 0xff;' and still get 1.5 volts.
>
> Thanks for your help,
> Josh
> avr-gcc-list at http://avr1.org



--
-------------------------------------------------------
private:        address@hidden
company:        address@hidden

avr-gcc-list at http://avr1.org