#include <stdio.h> #include <stdlib.h> #include <stdbool.h> #include <unistd.h> #define HIGH 1 #define LOW 0 #define INPUT 1 #define OUTPUT 0 int outputPin = 28; bool digitalPinMode(int pin, int dir){ FILE * fd; char fName[128]; // Exporting the pin to be used if(( fd = fopen("/sys/class/gpio/export", "w")) == NULL) { printf("Error: unable to export pin\n"); return false; } fprintf(fd, "%d\n", pin); fclose(fd); // Setting direction of the pin sprintf(fName, "/sys/class/gpio/gpio%d/direction", pin); if((fd = fopen(fName, "w")) == NULL) { printf("Error: can't open pin direction\n"); return false; } if(dir == OUTPUT) { fprintf(fd, "out\n"); } else { fprintf(fd, "in\n"); } fclose(fd); return true; } bool digitalWrite(int pin, int val) { FILE * fd; char fName[128]; // Open pin value file sprintf(fName, "/sys/class/gpio/gpio%d/value", pin); if((fd = fopen(fName, "w")) == NULL) { printf("Error: can't open pin value\n"); return false; } if(val == HIGH) { fprintf(fd, "1\n"); } else { fprintf(fd, "0\n"); } fclose(fd); return true; } int setup() { if (!digitalPinMode(outputPin, OUTPUT)) return -1; return 0; } int main(void) { if (setup() == -1) { exit(1); } while(1){ digitalWrite(outputPin, HIGH); sleep(1); digitalWrite(outputPin, LOW); sleep(1); } return 0; } |
