c - Arduino sketch 的字符串命令有点工作但不是真的

Question

所以我有一个 Arduino 草图，它读取串行命令(一串字符)，然后让草图根据它接收到的命令执行某些操作。截至目前，我有两个命令，

• {open_valve}
• {close_valve}

当我向 Arduino 发送命令 {open_valve} 时，阀门打开正常，但是当我向 Arduino 发送命令 {close_valve} 时阀门没有关闭。草图如下所示，

 // flow_A LED
 int led = 4;

 // relay_A
 const int RELAY_A = A0;

 // variables from sketch example
 String inputString = ""; // a string to hold incoming data
 boolean stringComplete = false; // whether the string is complete

 // variables from SO thread
 boolean LED_state = false;
 boolean vavle_open = false;

// flowmeter shit
unsigned long totalCount = 0;
unsigned long previousCount = 0;
int pin = 2;
unsigned long duration;

// storage variable for the timer
unsigned long previousMillis=0;
int interval=1000; //in milliseconds

// counters for each flowmeter
unsigned long countA = 0;

 void setup() {

   Serial.begin(115200); // open serial port, sets data rate to 115200bps
   Serial.println("Power on test");
   inputString.reserve(200);

   pinMode(RELAY_A, OUTPUT);

   // flowmeter shit
   pinMode(pin, INPUT);

}

void open_valve() {

  digitalWrite(RELAY_A, HIGH); // turn RELAY_A on

  // set the boolean value for "vavle_open" to true
  //valve_open = true;
  Serial.println("Valve Open");

}

void close_valve() {
  Serial.println("2");
  digitalWrite(RELAY_A, LOW); // turn RELAY_A off
  //valve_open = false;
  Serial.println("3");
  Serial.println("Vavle Closed");
}

void controlValve(bool open)
{

}

void flow_A_blink() {

  digitalWrite(led, HIGH); // turn the LED on (HIGH is the voltage level)
  delay(1000);              // wait for one second
  digitalWrite(led, LOW);   // turn the LED off by making the voltage LOW
  delay(1000);              // wait for a second
}

void flow_A_blink_stop() {

  digitalWrite(led, LOW);
}

void getFlow() {

  duration = pulseIn(pin, HIGH);
  Serial.print(duration);
  Serial.println("");
  delay(200);
}

/*
 * Main program loop, runs over and over repeatedly
 */

void loop() {
  if(checkForCorrectCommand("{open_valve}") == true) {
    open_valve();
    Serial.println("OPENING"); 
    getFlow();   
  }
  else if(checkForCorrectCommand("{close_valve}") == true)
  {
    close_valve();
    Serial.println("CLOSING");
  }
}

bool checkForCorrectCommand(String cmd) {  

    //Serial.println(inputString);
    //Serial.println(cmd);

    if(inputString == cmd) { 
     // reset String variables for serial data commands
     Serial.println("1");
     inputString = "";
     stringComplete = false;
     return true;
      // reset String variables for serial data commands
      inputString = "";
      stringComplete = false;
      return false;
    } 
}

//SerialEvent occurs whenever a new data comes in the
//hardware serial RX.  This routine is run between each
//time loop() runs, so using delay inside loop can delay
//response.  Multiple bytes of data may be available.

void serialEvent() {
  while(Serial.available()) {
    // get the new byte:
    char inChar = (char)Serial.read();
    // add it to the inputString:
    inputString += inChar;
    // if the incoming character is a newline, set a flag
    // so the main loop can do something about it:
    if (inChar == '\n') {
      stringComplete = true;
    }
  }
}

Answer 1

您的代码不应像此处粘贴的那样编译。 checkForCorrectCommand 函数没有匹配和不匹配的返回值。您的代码显示您打算为匹配和不匹配的情况清空 inputString 缓冲区。如果字符串匹配不正确，您希望保持输入缓冲区不变，以便可以运行以下测试用例。

bool checkForCorrectCommand(String cmd) {  

  if(inputString == cmd) { 
    // for match case, the string is consumed from the buffer
    inputString = "";
    stringComplete = false;
    return true;
  } 
  else {
    // for the non-match case, leave the buffer for further Rx or further tests
    return false;
  }