A couple of simple examples, we used an RGB LED breakout. This was a common anode type, so to switch an LED on you need to switch the appropriate port pin low.
Schematic
atmega and rgb led
Code
These examples were written in mikroC PRO for AVR
Example 1 : Cycle through Red, green and blue colours
void main() {
DDRB = 0xFF; // Set direction to be output
do {
PORTB = 0xFF; // Turn OFF diodes on PORTB
Delay_ms(200); // 1 second delay
PORTB = 0xFE;
Delay_ms(200); // 1 second delay
PORTB = 0xFD;
Delay_ms(200); // 1 second delay
PORTB = 0xFB;
Delay_ms(100); // 1 second delay
} while(1); // Endless loop
}
Example 2 : Cycle through all colours
void main()
{
DDRB = 0xFF;
PORTB = 0xFF; // Set RB0 to high 00000001
do // To set infinite loop
{
PORTB = PORTB - 0x01; //
Delay_ms(250);
if(PORTB == 0xF8) //11111000 = R,G,B on
{
PORTB = 0xFF; //LEDS off
Delay_ms(500);
}
}while(1); // To set infinite loop
}
Links
ATMEGA16/ATmega32 AVR Minimum System Board + USB ISP USBasp Programmer