Quote Originally Posted by tree_v1
Code:
int c; /* c is get char */
char d;  
float t;  /* t is how far away the lighting is */
Based on how you used c, the comment does not make sense. Rather, the later comment that c "is the amount of time between the flash and the sounds" should have mean placed here. d is an undescriptive name. Observe CommonTater's example with good comments:
Quote Originally Posted by CommonTater
Code:
int c;   // delay
char d;  // go again
float t; // distance
Incidentally, note that CommonTater used C99 specific comments; prefer your /* */ style of comments if you want to write code compliant with C89/C90.

Speaking of comments, I would go a step further and eliminate the comments by using better variable names:
Code:
int delay;
char go_again;
float distance;