Arduino 串行监视器和 LED

Question

I'm using an Arduino Pro Mini 168 @ 5v and am currently trying to control individual LED's using the Serial Monitor. I am having a bit of trouble with my code and execution of the program.

I used the following code and got the issue on compile saying "Home_Control:25: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]"

//Variable definitions
int LEDone = 3; //Grey wire
int LEDtwo = 5; //Yellow wire
int LEDthree = 6; //Brown wire


void setup() {
  Serial.begin(9600);
  pinMode(LEDone, OUTPUT); //Set Pins to OUTPUT
  pinMode(LEDtwo, OUTPUT);
  pinMode(LEDthree, OUTPUT);

}

void loop() {
 if (Serial.available() > 0)
  {
    char inputCommand = Serial.read();
    Serial.print(inputCommand);   
    Serial.print("        ");      
    Serial.print(inputCommand);
    Serial.print("       ");     
    Serial.print(char(inputCommand));

    if(inputCommand == "one")
    {
      digitalWrite(3, HIGH);
      digitalWrite(5, LOW);
      digitalWrite(6, LOW);
      Serial.print(" Lights set to Low ");
    }

    if(inputCommand == "two")
    {
      digitalWrite(3, HIGH);
      digitalWrite(5, HIGH);
      digitalWrite(6, LOW);
      Serial.print(" Lights set to Medium ");
    }

    if(inputCommand == "three")
    {
      digitalWrite(3, HIGH);
      digitalWrite(5, HIGH);
      digitalWrite(6, HIGH);
      Serial.print(" Lights set to High ");
    }


  }
}

I altered the code to this but it doesn't function on the Arduino. I recieve jibberish for the print functions as well, not sure if related:

//Variable definitions
int LEDone = 3; //Grey wire
int LEDtwo = 5; //Yellow wire
int LEDthree = 6; //Brown wire


void setup() {
  Serial.begin(9600);
  pinMode(LEDone, OUTPUT); //Set Pins to OUTPUT
  pinMode(LEDtwo, OUTPUT);
  pinMode(LEDthree, OUTPUT);

}

void loop() {
 if (Serial.available() > 0)
  {
    char inputCommand = Serial.read();
    Serial.print(inputCommand);   
    Serial.print("        ");      
    Serial.print(inputCommand);
    Serial.print("       ");     
    Serial.print(char(inputCommand));

    if(inputCommand == '1')
    {
      digitalWrite(3, HIGH);
      digitalWrite(5, LOW);
      digitalWrite(6, LOW);
      Serial.print(" Lights set to Low ");
    }

    if(inputCommand == '2')
    {
      digitalWrite(3, HIGH);
      digitalWrite(5, HIGH);
      digitalWrite(6, LOW);
      Serial.print(" Lights set to Medium ");
    }

    if(inputCommand == '3')
    {
      digitalWrite(3, HIGH);
      digitalWrite(5, HIGH);
      digitalWrite(6, HIGH);
      Serial.print(" Lights set to High ");
    }


  }
}

Attached is also the setup for my Arduino, if you see any errors in my wiring or my code please let me know! :)

Pictures: ALBUM

Answer 1

Your second code is the most "correct", in my opinion, because you are using less chars.

As others have pointed out, the first one is wrong because you can't compare chars and strings. If you want to use strings use Ramesh-X's answer, even if I don't like variable size buffers.

Anyway, the second example prints, I think, a lot of lines because you also interprete the new line chars. Moreover I think a switch statement is more clean. So, just replace it with

if (Serial.available() > 0)
{
    char inputCommand = Serial.read();
    if ((inputCommand != '\r') && (inputCommand != '\n'))
    {
        Serial.print(inputCommand);   
        Serial.print("        ");      
        Serial.print(inputCommand);
        Serial.print("       ");     
        Serial.print(char(inputCommand));
    }

    switch (inputCommand)
    {
    case '1':
        digitalWrite(3, HIGH);
        digitalWrite(5, LOW);
        digitalWrite(6, LOW);
        Serial.print(" Lights set to Low ");
        break;
    case '2':
        digitalWrite(3, HIGH);
        digitalWrite(5, HIGH);
        digitalWrite(6, LOW);
        Serial.print(" Lights set to Medium ");
        break;
    case '3':
        digitalWrite(3, HIGH);
        digitalWrite(5, HIGH);
        digitalWrite(6, HIGH);
        Serial.print(" Lights set to High ");
        break;
    }
}

EDIT: just to test the serial communication, use this sketch:

void setup()
{
    Serial.begin(9600);
}

void loop()
{
    if (Serial.available() > 0)
    {
        char inputCommand = Serial.read();
        if ((inputCommand >= 'a') && (inputCommand <= 'z'))
            inputCommand = inputCommand + 'A' - 'a';
        Serial.print(inputCommand);
    }
}

This should print back what you type, but as soon as you write lowercase letters it will print uppercase (eg if you write Hello there! it should print HELLO THERE! )

Try this and let us know if it works

Answer 2

Try this one.

String data = "";
void loop() {
  if(Serial.available())
  {
    data += (char)Serial.read();
  }

  if(inputCommand == "one")
  {
    digitalWrite(3, HIGH);
    digitalWrite(5, LOW);
    digitalWrite(6, LOW);
    Serial.print(" Lights set to Low ");
    data = "";
  }

  if(inputCommand == "two")
  {
    digitalWrite(3, HIGH);
    digitalWrite(5, HIGH);
    digitalWrite(6, LOW);
    Serial.print(" Lights set to Medium ");
    data = "";
  }

  if(inputCommand == "three")
  {
    digitalWrite(3, HIGH);
    digitalWrite(5, HIGH);
    digitalWrite(6, HIGH);
    Serial.print(" Lights set to High ");
    data = "";
  }
}

What you meant by jibberish is not clear. If you meant that you get unwanted characters, check your baud rate. If you are getting another String that you typed, other than what you expected, check again your code.

This code will work if there is no problem in baud rate..