I have just add a line ( PORTA = 0;) in the exemple program "blink a led" to test if the AVR register can be use.
The board used is Arduino Uno.
Here is the code :
/*
Blink
Turns on an LED on for one second, then off for one second, repeatedly.
This example code is in the public domain.*/
void setup() {
// initialize the digital pin as an output.
// Pin 13 has an LED connected on most Arduino boards:
pinMode(13, OUTPUT);
PORTA = 0; // Add line
}
void loop() {
digitalWrite(13, HIGH); // set the LED on
delay(1000); // wait for a second
digitalWrite(13, LOW); // set the LED off
delay(1000); // wait for a second
}