Incrementing value of i; Why doesn't it work?!?

Using Arduino Programming Questions
#1

Hey can somebody please tell me where I have done the dummy mistake and why it doesn’t work?

It alway gives out zeros for both x and y in the serial print.

int i;
int x;
int y;
void setup() {

Serial.begin(9600);


}
void loop() {
  
for (i=0; i < 2*PI; i++);
 

 x = sin(i);
 y = cos(i);
 
 
 Serial.print("x = ");     
 Serial.print(y);
 Serial.print("\t y = ");
 Serial.println(y);

 delay(20);    

}
#2

Trigonometric values are not integers.

#3

And your printing y twice and not printing x at all.

Mark

#4

do not put a semicolon after the if for()

Moderator edit: Correction

#5

sin and cosine are always less than one, so if you round the float answer to an integer, you will always get zero.

#6

Do put some braces after the "for"

#7

I cleaned it up a bit, it was fun to do…

// Trig Test

int d;    // degrees
float r;  // radians
float s;
float c;
void setup() {

  Serial.begin(9600);


}
void loop() {

  for (d = 0; d <= 360; d += 10) {    // step by 10 to cut down the clutter and see the functions

    r = d * PI / 180 ;   //convert degrees to rad for Arduino trig funtions
    s = sin(r);
    c = cos(r);

    Serial.print(" deg = ");
    Serial.print(d);
    Serial.print("\t sin = ");
    Serial.print(s, 4);             // ,4  is 4 decimal places
    Serial.print("\t   cos= ");
    Serial.println(c, 4);

    delay(100);           // lets you see it work...

  }
  Serial.println();      // throws a blank line at the end
  Serial.end();          // kills output after 1 cycle
}
#8