 #define STEER_RUN 	2000
 #define STEER_LUN       1000
 #define STEER_TIME 	800
+#define STEER_UNIT      0.1
 #define STEER_INTER_1   2 //pin 21
 #define STEER_INTER_2   3 //pin 20
 #define STEER_INTER_G   4 //pin 19

Servo brake;

int readSpeed;
volatile int steeringAngle = 0;
int steerSetTime;
boolean forwardDirection = true;
volatile boolean brake_state = false;

  SPI.setBitOrder(MSBFIRST);
  SPI.begin();

  attachInterrupt(STEER_INTER_1, steer_inter_1, CHANGE); 
  attachInterrupt(STEER_INTER_2, steer_inter_2, CHANGE);
  attachInterrupt(STEER_INTER_G, steer_inter_180, RISING);
  steer.attach(STEER_PIN);
  
  attachInterrupt(BRAKE_ON_PIN, brakeState, RISING);
