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  1. #include <stdio.h>
  2. #include <pthread.h>
  3. #include <time.h>
  4. //#include <wiringPi.h>
  5. #define HIGH 1
  6. #define LOW 0
  7.  
  8. int led_freq = 100; // Hz
  9.  
  10.  
  11. int global_set_first = HIGH;
  12. int global_set_second = LOW;
  13. long period_us = 5000;
  14. int cycle_ish = 200;
  15.  
  16. void set_led_brightness(int i){
  17.  
  18. 	if (i > led_freq || i < 1) {
  19. 		i = led_freq / 2;
  20. 	}
  21.  
  22. 	if (i > led_freq/2) {
  23. 		i = led_freq - i;
  24. 		global_set_first = LOW;
  25. 		global_set_second = HIGH;
  26. 	} else {
  27. 		global_set_first = HIGH;
  28. 		global_set_second = LOW;
  29. 	}
  30. 	cycle_ish = led_freq/i;
  31.  
  32. }
  33.  
  34. void timespec_add_us(struct timespec *t, long us)
  35. {
  36. 	// add microseconds to timespecs nanosecond counter
  37. 	t->tv_nsec += us*1000;
  38.  
  39. 	// if wrapping nanosecond counter, increment second counter
  40. 	if (t->tv_nsec > 1000000000)
  41. 	{
  42. 		t->tv_nsec -= 1000000000;
  43. 		t->tv_sec += 1;
  44. 	}
  45. }
  46.  
  47. void* task(void* v){
  48.  
  49. 	int counter = 0;
  50. 	struct timespec wait_time_v;
  51. 	clock_gettime(CLOCK_REALTIME, &wait_time_v);
  52.  
  53. 	while (1) {
  54.  
  55. 		if (counter >= cycle_ish) {
  56. 			//digitalWrite(0, global_set_first);
  57. 			counter = 0;
  58. 		} else {
  59. 			//digitalWrite(0,global_set_second);
  60. 		}
  61.  
  62. 		timespec_add_us(&wait_time_v, period_us);
  63. 		clock_nanosleep(CLOCK_REALTIME, TIMER_ABSTIME, &wait_time_v, NULL);
  64.  
  65. 		counter++;
  66. 	}
  67. 	return 0;
  68. }
  69.  
  70. int main(int argc, char *argv[]){
  71. 	period_us = 1000000/led_freq;
  72.  
  73. 	int i=100;
  74. 	if (argc == 2) {
  75. 		i = atoi(argv[1]);
  76. 	}
  77.  
  78. //	wiringPiSetup();
  79. //	pinMode(0, OUTPUT);
  80.  
  81. 	pthread_t p;
  82.  
  83. 	pthread_create(&p, NULL, task, (void*) &i);
  84. 	int input;
  85. 	while (1) {
  86.  
  87. 		scanf("%d", &input);
  88. 		//set_led_brightness(input);
  89. 	}
  90. 	/*
  91. 	int a;
  92. 	for (a = 199; a > 1; a-=10) {
  93. 		set_led_brightness(a);
  94. 		printf("i = %d\n", a);
  95. 		usleep(1000000);
  96. 	}
  97. 	for (a = 1; a < 200; a+=10) {
  98. 		set_led_brightness(a);
  99. 		printf("i = %d\n", a);
  100. 		usleep(1000000);
  101. 	}
  102. 	 */
  103. 	pthread_join(p, NULL);
  104.  
  105.  
  106. return 0;
  107. }
  108.  
Compilation error #stdin compilation error #stdout 0s 0KB
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stdin
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Standard input is empty
compilation info 
prog.c: In function ‘main’:
prog.c:75:3: warning: implicit declaration of function ‘atoi’ [-Wimplicit-function-declaration]
   i = atoi(argv[1]);
   ^
/home/9O5uq1/cc64YdI0.o: In function `main':
prog.c:(.text.startup+0x4d): undefined reference to `pthread_create'
collect2: error: ld returned 1 exit status
stdout
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Standard output is empty
https://ideone.com/TxmfwC
language:
C (gcc 8.3)
created:
10 years ago
visibility:
public

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