AVR C – Hello World [LED Blink]

Select your favorite Arduino board and connect the LED into PB0 (PORTB pin 0). Refer the Pinout diagram of your arduino to find the proper pin (here it is the digital 8 pin).

Next you can use the usual arduino IDE to upload the AVR C codes as well. Open the Arduino IDE and delete the all the existing codes and type the following code and upload the code into arduino.

#include <avr/io.h>
#include <util/delay.h>
#define BLINK_DELAY_MS 200

int main(void){
   //IO Pin Settings
   DDRB=0b00000001;
   //PB0 output 
   PORTB=0x1; //write 1 to PB0, rest 0 
   
   while(1){ 
       PORTB=PORTB ^ (1<<0); //toggling 0 th bit 
       _delay_ms(BLINK_DELAY_MS); 
   } 
}