// input.c // // Example program for bcm2835 library // Reads and prints the state of an input pin // // After installing bcm2835, you can build this // with something like: // gcc -o input input.c -l bcm2835 // sudo ./input // // Or you can test it before installing with: // gcc -o input -I ../../src ../../src/bcm2835.c input.c // sudo ./input // // Author: Mike McCauley // Copyright (C) 2011 Mike McCauley // $Id: RF22.h,v 1.21 2012/05/30 01:51:25 mikem Exp $ #include #include // Input on RPi pin GPIO 15 #define PIN RPI_GPIO_P1_15 int main(int argc, char **argv) { // 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; }