gpio.c

/*
 * untitled.c
 * 
 * Copyright 2013  <pi@raspberrypi>
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 * MA 02110-1301, USA.
 * 
 * 
 */


#include <stdio.h>
#include <bcm2835.h>


// Input on RPi pin GPIO 15
#define PIN RPI_GPIO_P1_15


extern int test_gpio()
{
	// If you call this, it will not actually access the GPIO
	// Use for testing
	// bcm2835_set_debug(1);

    if (!bcm2835_init())
	return 1;

    // Set RPI pin P1-15 to be an input
    bcm2835_gpio_fsel(PIN, BCM2835_GPIO_FSEL_INPT);
    //  with a pullup
    bcm2835_gpio_set_pud(PIN, BCM2835_GPIO_PUD_UP);

    // Blink
    while (1)
    {
	// Read some data
	uint8_t value = bcm2835_gpio_lev(PIN);
	printf("read from pin 15: %d\n", value);
	
	// wait a bit
	delay(500);
    }

    bcm2835_close();
	
	return 0;
}