server/actuators/ledtest.c

   1 #include "ledtest.h"
   2
   3 bool Ledtest_Set(int id, double value)
   4 {
   5
   6         FILE *led_handle = NULL;        //code reference: http://learnbuildshare.wordpress.com/2013/05/19/beaglebone-black-controlling-user-leds
   7         const char *led_format = "/sys/class/leds/beaglebone:green:usr%d/brightness";
   8         char buf[50];
   9         bool turn_on = value;
  10
  11         for (int i = 0; i < 4; i++)
  12         {
  13                 snprintf(buf, 50, led_format, i);
  14                 if ((led_handle = fopen(buf, "w")) != NULL)
  15                 {
  16                         if (turn_on)
  17                                 fwrite("1", sizeof(char), 1, led_handle);
  18                         else
  19                                 fwrite("0", sizeof(char), 1, led_handle);
  20                         fclose(led_handle);
  21                 }
  22                 else
  23                 {
  24                         Log(LOGDEBUG, "LED fopen failed: %s", strerror(errno));
  25                         return false;
  26                 }
  27         }
  28         return true;
  29 }