arduino电子门禁

#include <SoftwareSerial.h>
#include <Servo.h>

#define MAX_BUF_LEN 32
#define SERVO_PIN 5
#define SERVO_RESET 120   // degree
#define SERVO_STEP_SIZE 2
#define SERVO_STEP_DELAY 40 // in ms

static char buf[MAX_BUF_LEN] = {0};
Servo servo;


void servo_move(Servo& s, int old_degree, int new_degree, int step_size, int step_delay)
{
  int i=0;
  if(new_degree<0) new_degree=0;
  else if(new_degree>180) new_degree=180;

  if(old_degree>new_degree){
    for(i=old_degree-step_size;i>new_degree;i-=step_size){
      s.write(i);
      delay(step_delay);
    }
  }else if(old_degree<new_degree){
     for(i=old_degree+step_size;i<new_degree;i+=step_size){
      s.write(i);
      delay(step_delay);
    }
  }

  if(i!=new_degree) s.write(new_degree);
  delay(step_delay);
}


void setup()
{
 // Open serial communications and wait for port to open:
  Serial.begin(57600);

  servo.attach(SERVO_PIN);

  int old_degree=servo.read();
  servo_move(servo,old_degree,SERVO_RESET,SERVO_STEP_SIZE,SERVO_STEP_DELAY);

}



void process_command(Servo& s, char* buf, int len)
{
  int old_degree,new_degree;
  int inc100, inc10,inc,val;

  if(len<6 || buf[0]=='+') return;

  inc100=buf[3]-'0';
  inc100=100*inc100;
  inc10=buf[4]-'0';
  inc10=10*inc10;
  inc=buf[5]-'0';

  val=inc100+inc10+inc;

  if(val<0) val=0;
  else if(val>180) val=180;

  old_degree=servo.read();

  if(buf[0]=='i' && buf[1]=='n' && buf[2]=='c') {
    new_degree=old_degree+val;
    if(new_degree>180)new_degree=180;
    servo_move(servo, old_degree, old_degree+val, SERVO_STEP_SIZE, SERVO_STEP_DELAY);
  }else if(buf[0]=='d' && buf[1]=='e' && buf[2]=='c'){
    new_degree=old_degree-val;
    if(new_degree<0)new_degree=0;
    servo_move(servo, old_degree, new_degree, SERVO_STEP_SIZE, SERVO_STEP_DELAY);
  }else if(buf[0]=='s' && buf[1]=='e' && buf[2]=='t'){
    servo_move(servo, old_degree, val, SERVO_STEP_SIZE, SERVO_STEP_DELAY);
  }

}

void loop()
{

  static int i=0;

  if (Serial.available()){
    buf[i]=Serial.read();
    if(buf[i]=='\n'){
      buf[i]=0;
      process_command(servo, buf,i);
      i=0;
    } else i++;
  }

}