resens-hexapod_how-to-control-angular-position-using-servo-motor_01.txt

#define T_SAFE      10 // minimum low/high in one duty cycle to avoid zero value
#define T_MIN       500 // min value for HIGH period
#define T_MAX       2500 // max value for HIGH period
#define T           T_MAX+T_SAFE // duty cycle for servo motor in micro-seconds

int servo_pin = 9; // PWM pin

void setup() {
  pinMode(servo_pin, OUTPUT);  // sets the pin as output

  // start at angle = 0
  th = T_MIN;
  tl = T - th;

  // rotate motor using pulse-width
  digitalWrite(servo_pin, HIGH);
  delayMicroseconds(th);
  digitalWrite(servo_pin, LOW);
  delayMicroseconds(tl);
}