DVK512 button and LED example

This is a simple example using the Waveshare DVK512. You press a key and this is displayed on the command line, one of the 4 LEDs is also lit for each of the 4 buttons on the board

You can see the LEDS (9) and Buttons (10) in the picture below

Code

[codesyntax lang=”cpp”]

/* key.c
 * you can build this like: 
 * gcc -Wall key.c -o key -lwiringPi
 * sudo ./key
*/
#include <stdio.h>
#include <string.h> 
#include <errno.h>

#include<wiringPi.h>


char KEY[]={21,22,23,24};
char LED[]={25,26,27,28};
unsigned char i;

int main(){
	if (wiringPiSetup() < 0)return 1 ;
	
    for(i=0;i<4;i++)
	{
		pinMode (LED[i],OUTPUT) ;
	}

	for(i=0;i<4;i++)
	{
		pinMode (KEY[i],INPUT) ;//pinMode (LED, OUTPUT) ;
		pullUpDnControl(KEY[i], PUD_UP);
	}

	while(1)
	{
 		for(i=0;i<4;i++)
		{
			if (digitalRead (KEY[i]) == 0)  
    			{
				printf ("press the key : %d\n",i) ;
				digitalWrite (LED[i], 1) ;
    			delay(500);
				digitalWrite (LED[i], 0) ;
			}
  		}
	}
}

[/codesyntax]

Link

 
DVK512 # Raspberry Pi Model 2 B/B+/A+ Expansion/Evaluation Development Board with various interfaces