MATLAB在Arduino中写入串行缓慢

Question

我想通过串口将命令从MATLAB发送到Arduino，但我遇到了一些问题。我有一个需要左右旋转的步进电机，应该检查传感器是否到达应该的位置。

MATLAB连接代码：

function arduino = conn()
    arduino = serial('COM4','BaudRate', 19200);
    fopen(arduino);
    pause(3);
end

和Arduino：

int pin = 2;
int pinValue;
int pinHuman = 3;
const int stepPin = A5; 
const int dirPin = A4; 
int readV;
int valueHuman;
int tim = 10000;
String vl1 = "";
String vl2 = "";
String vl = "";

void setup() 
{
   Serial.begin(19200);
   Serial.setTimeout(10);
   pinMode(stepPin,OUTPUT); 
   pinMode(dirPin,OUTPUT);
   pinMode(pin,INPUT_PULLUP);
   pinMode(pinHuman,INPUT_PULLUP);
}

void loop() 
{
   valueHuman= digitalRead(pinHuman);
   pinValue= digitalRead(pin); 
   vl1 = (String)valueHuman;
   vl2 = (String)pinValue;
   vl = "2" +vl1 + "" + vl2 + "3";
   Serial.println(vl);
   if (Serial.available() > 0) 
   {   
       readV= Serial.read();  
       if(readV== 48)
       {
           digitalWrite(dirPin,1);
           rotateBase();  
           rotate(1);   
       }
       if(readV== 49)
       {
           digitalWrite(dirPin,0);
           rotateBase();  
           rotate(0); 
       }
   }  
}

void rotate(int d)
{
    pinValue= digitalRead(pin);  
    while(pinValue== 0)
    {        
        pinValue= digitalRead(pin);   
        digitalWrite(dirPin,d); 
        digitalWrite(stepPin,HIGH); 
        delay(5); 
        digitalWrite(stepPin,LOW);   
        delay(5);
        pinValue= digitalRead(pin); 
        vl2 = (String)pinValue;
        vl = "2" +vl1 + "" + vl2 + "3";
        Serial.println(vl);
    }  
}

void rotateBase()
{
    for(int i = 0; i<120; i++)
    {
        digitalWrite(stepPin,HIGH); 
        delayMicroseconds(tim); 
        tim = tim - 32;
        digitalWrite(stepPin,LOW);   
        delayMicroseconds(tim);        
        tim = tim - 32;
        pinValue= digitalRead(pin); 
        vl2 = (String)pinValue;
        vl = "2" +vl1 + "" + vl2 + "3";
        Serial.println(vl);
    }
    delayMicroseconds(tim-10);
    for(int i = 0; i<560; i++)
    {
        digitalWrite(stepPin,HIGH); 
        delayMicroseconds(2300); 
        digitalWrite(stepPin,LOW);   
        delayMicroseconds(2300);
        pinValue= digitalRead(pin); 
        vl2 = (String)pinValue;
        vl = "2" +vl1 + "" + vl2 + "3";
        Serial.println(vl);
    }
    delayMicroseconds(tim-10);
    for(int i = 0; i<120; i++)
    {
        digitalWrite(stepPin,HIGH); 
        delayMicroseconds(tim); 
        tim = tim + 32;
        digitalWrite(stepPin,LOW);   
        delayMicroseconds(tim);        
        tim = tim + 32;
        pinValue= digitalRead(pin); 
        vl2 = (String)pinValue;
        vl = "2" +vl1 + "" + vl2 + "3";
        Serial.println(vl);
    }  
    tim = 10000; 
}

从MALAB通过序列写入Arduino：

function rotateBase(arduino,d)
    sensors = [0,0];
    fprintf(arduino,'%i',d);
    pause(1)
    readR = native2unicode(fread(arduino));
    while sensors(2)~= 1
        sensors =decodeMessage(readR); //decodeMessage(array) updates sensors array based on arduino output
        readR = native2unicode(fread(arduino));
    end
end

所以，如果我创建arduino连接：

arduino = conn;

如果我尝试沟通：

rotateBase(arduino,0);

命令后电机开始旋转3-5秒

fprintf(arduino,'%i',d); 

已执行。我无法解决这个延迟问题，任何帮助都将不胜感激。