====== Digito i/o with Studyboard ======
{{:et:naited:digi:io.jpg?300|}}

Studyboard ‚Basic’ includes three outputs (LED) and three inputs (microswitch)
LEDs are connected to PORTC[3..5] and switches PORTC[0..2]. 

This simple examples demonstrates how to switch on LED when pushing appropriate switch.


Connection schema:

{{:et:harjutused:digi:1a_skeem.jpg?500|}}

Example C code:

<code c>
/* Labor 1 example
Example works with Studyboard Basic v3

Press S1 - LED1 goes ON
Press S2 - LED2 goes ON
Press S31 - LED3 goes ON
Raivo Sell 2008

LED = 0 (ON)  		LED = 1 (OFF)
S	= 0 (ON) 	S	= 1 (OFF)

PORT direction: 1-output	0-input */

#include <avr\io.h>

//defineeritakse kõrge bit pordis x
#define SET(x) |= (1<<x)  

//defineeritakse madal bit pordis x
#define CLR(x) &=~(1<<x)  

int main(void) {

    DDRC  = 0x38;  // DDRC  0bXX111000
    PORTC = 0x3F;  // PORTC 0bXX111111

	//Lõputu tsükkel
	while(1) {
		// Kui toimub nupule vajutus
		if (bit_is_clear(PINC, 0))	//Nupp S1
			PORTC CLR(3); //LED 1 sisse
		else if (bit_is_clear(PINC, 1))//Nupp S2
			PORTC CLR(4); //LED 2 sisse
		else if (bit_is_clear(PINC, 2))//Nupp S3
			PORTC CLR(5); //LED 3 sisse
		else //Kui pole midagi vajutatud
			PORTC=0xFF;		//LED lülitatakse välja (LED=1)
	}
}
</code>