通过HC-06修复向arduino发送命令的延迟

Question

我和我的朋友正在研究一个关于arduino的小项目。我们正在尝试使用Arduino和蓝牙模块制作遥控车。除了一个，一切都很顺利。当我们向arduino发送信号以使汽车在特定方向上移动时，它会迟到。接近8到10秒。无论如何要解决它吗？我们使用串口显示检查了延迟。该命令收到很大的延迟。代码如下。我们使用的是Arduino Uno，蓝牙模块是HC-06，Arduino IDE版本是1.6.7。我们正在使用Android应用程序从手机发送命令。

#define trigPin 7
#define echoPin 6
#define yellowLed 10
#define greenLed 9

int motor_left[] = {2, 3};
int motor_right[] = {4, 5};
int vSpeed=255;
long previousMillis = -1000*10;
char state = 'S';

void setup() {
  // put your setup code here, to run once:
  Serial.begin (9600);
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);

  pinMode(greenLed, OUTPUT);
  pinMode(yellowLed, OUTPUT);

  for(int i = 0; i < 2; i++){
    pinMode(motor_left[i], OUTPUT);
    pinMode(motor_right[i], OUTPUT);
  }
}

void loop() {
  // put your main code here, to run repeatedly:
  long duration, inches, cm;
  if(Serial.available() > 0){     
        state = Serial.read();
  }

  // The PING))) is triggered by a HIGH pulse of 2 or more microseconds.
  // Give a short LOW pulse beforehand to ensure a clean HIGH pulse:
  digitalWrite (trigPin, LOW);
  delayMicroseconds (2);
  digitalWrite (trigPin, HIGH);
  delayMicroseconds (10);
  digitalWrite (trigPin, LOW);

  duration = pulseIn (echoPin, HIGH);

  inches = microsecondsToInches (duration);
  cm = microsecondsToCentimeters (duration);

  if (cm <= 10 || state == 'S') {
    motor_stop ();
  } else {
    motor_ready ();
  }

  delay(100);
}

void motor_stop(){
  Serial.print (state);
  Serial.println();
  digitalWrite(motor_left[0], LOW); 
  digitalWrite(motor_left[1], LOW); 

  digitalWrite(motor_right[0], LOW);
  digitalWrite(motor_right[1], LOW);

  digitalWrite (yellowLed, HIGH);
  digitalWrite (greenLed, LOW);
  delay(25);
}

void motor_ready () {
    Serial.print (state);
    Serial.println();

    if (state == '0') {
        vSpeed = 0;
    } else if (state == '1') {
        vSpeed = 75;
    } else if (state == '2') {
        vSpeed = 150;
    } else if (state == '3') {
        vSpeed = 200;
    } else if (state == '4') {
        vSpeed = 255;
    }

    if (state == 'F') {
        driveForward (); 
    } else if (state == 'G') {
        driveForwardLeft (); 
    } else if (state == 'I') {
        driveForwardRight (); 
    } else if (state == 'B') {
        driveBackward (); 
    } else if (state == 'H') {
        driveBackwardLeft (); 
    } else if (state == 'J') {
        driveBackwardRight (); 
    }

    digitalWrite (yellowLed, LOW);
    digitalWrite (greenLed, HIGH);
}

void driveForward () {
    analogWrite(motor_left [0], vSpeed); analogWrite(motor_left [1], 0);
    analogWrite(motor_right [0], vSpeed);      analogWrite(motor_right [1], 0);
}

void driveForwardLeft () {
    analogWrite(motor_left [0], 0); analogWrite(motor_left [1], 0);
    analogWrite(motor_right [0], vSpeed);      analogWrite(motor_right [1], 0);
}

void driveForwardRight () {
    analogWrite(motor_left [0], vSpeed); analogWrite(motor_left [1], 0);
    analogWrite(motor_right [0], 0);      analogWrite(motor_right [1], 0);
}

void driveBackward () {
    analogWrite(motor_left [0], 0); analogWrite(motor_left [1], vSpeed);
    analogWrite(motor_right [0], 0);      analogWrite(motor_right [1], vSpeed);
}

void driveBackwardLeft () {
    analogWrite(motor_left [0], 0); analogWrite(motor_left [1], 0);
    analogWrite(motor_right [0], 0);      analogWrite(motor_right [1], vSpeed);
}

void driveBackwardRight () {
    analogWrite(motor_left [0], 0); analogWrite(motor_left [1], vSpeed);
    analogWrite(motor_right [0], 0);      analogWrite(motor_right [1], 0);
}

long microsecondsToInches(long microseconds) {
  return microseconds / 74 / 2;
}

long microsecondsToCentimeters(long microseconds) {
  return microseconds / 29 / 2;
}