//---------------------------------------------------------------------------------------
// Programm Nr.: 02
// Content     : Set LED at PORTD on pressing key
// Author      : digital AG Halle
// Date        : 13.07.2008
// System      : ATmega8-16PU - Dai Hoc Hue Development Board
//---------------------------------------------------------------------------------------

//--included Files-----------------------------------------------------------------------

#include <avr/io.h>

//--declarations-------------------------------------------------------------------------

uint8_t KEYS; 	//8-Bit integer variable (0...255) for actual key-value

//--MAIN PROGRAMM------------------------------------------------------------------------

int main()
{

	//--INITIALISATION---------------------------------------------------------------

	DDRC=225;	//PORT C: Bit 1,2,3,4 are inputs (Keys 1 - 4)
	PORTC=30;	//PORT C: Bit 1,2,3,4 internal Pullup-Resistors active

	DDRD=255; 	//Port D: all Bits defined as output (for the status LEDs)


	//--PROGRAMM CODE BEFORE MAIN LOOP (USED JUST ONE TIME)--------------------------

	PORTD=255; 	//Every LED at PORT D is off

	//--MAIN LOOP--------------------------------------------------------------------
	
	while(1)
	{
		KEYS=PINC;	//read input byte from PORT C into variable KEYS

		//mask = 1110 0010 = 226 dec.
		if ((KEYS&226)==!(02))	//if key 1 was pressed (PORT C Bit 1)
		{
			PORTD=254;		//set bit 0 at PORTD (LED1->on)	
			//(setting a full byte)
		}
		
			//mask = 1110 0100 = 228 dec.
		if ((KEYS&228)==!(04))	//if key 2 was pressed (PORT C Bit 2)
		{
			PORTD |= (1<<PD1);	//set bit 1 at PORTD (LED1->on)	
			//(setting only 1 bit - no touching the other bits)
		}

	}
}
//--PROGRAMM END------------------------------------------------------------------------