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/* Thinger to read 60hz cycle times and display diagnostics in a kind
* of stripcharty way.
*/
#include <unistd.h>
#include <stdio.h>
#include <string.h>
#include <fcntl.h>
#include <time.h>
// window for reporting, in cycles
#define REPORT_FREQ 60
// width of the bargraph
#define WIDTH 40
// timer cycles per second
#define SCALE 1000000
// length between nominal timer overflows, in microseconds
// (1 overflow / 65'536 microseconds) * (1'000'000 microseconds)
#define TICKSIZE (SCALE / 65536)
#define NANOSECOND 1000000000
#define MILLISECOND 1000
#define NOMINAL 60
#define MOTION 0.2
int main(int *argc, char **argv)
{
char line[WIDTH + 10];
char blankline[] = " | ";
double bottom = SCALE/(NOMINAL-MOTION);
double top = SCALE/(NOMINAL+MOTION);
double center = SCALE/(NOMINAL);
int counter;
int qpos = 0;
int fd = open("/dev/ttyACM0", O_RDONLY);
long int count_total = 0; // total overflows so far ever
struct timespec initial; // initial timestamp
signed long long int initial_nsec;
signed long int initial_msec;
strcpy(&line, &blankline);
clock_gettime(CLOCK_REALTIME, &initial);
initial_nsec = initial.tv_nsec;
initial_msec = (initial.tv_sec * 1000) + (initial.tv_nsec / (1000 * 1000));
while (1) {
double current, average;
char inlin[20];
int position, pos_avg, i;
int len;
struct timespec current_time;
signed long long int cur_nsec;
signed long int cur_msec;
long double nominal, measured;
len = read(fd, &inlin, 1);
if (len == 0) {
puts("Fucked\n");
continue;
}
clock_gettime(CLOCK_REALTIME, ¤t_time);
cur_nsec = (current_time.tv_nsec) + ((current_time.tv_sec - initial.tv_sec) * 1000 * 1000 * 1000);
cur_msec = (current_time.tv_nsec / (1000 * 1000)) + ((current_time.tv_sec) * 1000);
count_total++;
nominal = (long double) count_total / TICKSIZE;
//measured = (cur_nsec - initial_nsec) / NANOSECOND;
measured = (cur_msec - initial_msec) / MILLISECOND;
printf("% '05.8Lf - % '05.8Lf, % '05.8Lf\n", nominal, measured, measured/nominal);
}
}
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