I wrote this simple program:
#include <avr/io.h>
int main(void) {
DDRA = 0xff;
PORTA = 0xff;
while(1) {
}
}
When I program it to my brand new ATmega16A-PU, avrdude tells me that everything's fine. But when I connect an LED to port A, it never gets enabled.
For compiling the program and flashing it onto the ATmega, I use the following commands:
avr-gcc -mmcu=atmega16 -c -o test.o test.c
avr-gcc -mmcu=atmega16 -o test.elf test.o
avrdude -p m16 -c avrispv2 -P usb -U flash:w:test.elf
The following pins of the microcontroller are connected:
40 PA0 ---------> 220 Ω --> green LED --> GND
06 PB5 (MOSI) --> MOSI of the programmer
07 PB6 (MISO) --> MISO of the programmer
08 PB7 (SCK) ---> SCK of the programmer
09 RESET -------> RESET of the programmer
10 VCC ---------> VCC of the programmer
11 GND ---------> GND of the programmer
When I connect the left end of the 220 Ω resistor directly to VCC, the LED glows, so the LED is ok. The microcontroller is brand new and I already tried another one (also brand new), so I think they are ok too.
EDIT: the fuses are set to 0b10011001 (high) and 0b11100001 (low).
Any idea, why the microcontroller does not set port PA0 to VCC?
Best Answer
Too much details for a comment, so I chose to write it as answer.
Try these commands:
Check http://git.linformatronics.nl/gitweb/?p=makefile;a=summary for a generic Makefile. It'll need some tweaking as I am using a different programmer and controller, but it should be pretty straightforward.