c - HC-05 ⸮ 串行不起作用

Question

我最近为我的 arduino 购买了一个 HC-05 蓝牙模块，但我无法从中发送或接收数据。我使用代码来打开或关闭 LED，但是当我从 PC 的串行监视器发送一个字符后，我得到 ⸮。并且模块不响应任何AT命令。 HC-05 Connection Arduino connection我以 9600 和 38400 波特率运行串行，但没有任何变化。我也尝试过无行结尾以及 NL 和 CR。但是这个模块有问题吗？这是我的代码:

/*
Arduino Turn LED On/Off using Serial Commands
Created April 22, 2015
Hammad Tariq, Incubator (Pakistan)

It's a simple sketch which waits for a character on serial
and in case of a desirable character, it turns an LED on/off.

Possible string values:
a (to turn the LED on)
b (tor turn the LED off)
*/

char junk;
String inputString="";

void setup()                    // run once, when the sketch starts
{
 Serial.begin(9600);            // set the baud rate to 9600, same     should be of your Serial Monitor
 pinMode(13, OUTPUT);
}

void loop()
{
  if(Serial.available()){
  while(Serial.available())
    {
      char inChar = (char)Serial.read(); //read the input
      inputString += inChar;        //make a string of the characters     coming on serial
    }
    Serial.println(inputString);
    while (Serial.available() > 0)  
    { junk = Serial.read() ; }      // clear the serial buffer
    if(inputString == "a"){         //in case of 'a' turn the LED on
      digitalWrite(13, HIGH);  
    }else if(inputString == "b"){   //incase of 'b' turn the LED off
      digitalWrite(13, LOW);
    }
    inputString = "";
  }
}

Answer 1

我会一步一步走下去-连接Arduino 引脚 蓝牙引脚

RX(引脚 0)———-> TX

TX(引脚 1)———-> RX

5V ———-> VCC

接地——->接地

将 LED 负极连接到 arduino 的 GND，正极连接到引脚 13，电阻值在 220Ω – 1KΩ 之间。电路就完成了。注意:不要将蓝牙的RX对RX和TX对TX连接到arduino，您将不会收到任何数据，这里TX表示传输，RX表示接收。

/*
* This program lets you to control a LED on pin 13 of arduino using a bluetooth module
*/
char data = 0;            //Variable for storing received data
void setup()
{
    Serial.begin(9600);   //Sets the baud for serial data transmission                               
    pinMode(13, OUTPUT);  //Sets digital pin 13 as output pin
}
void loop()
{
   if(Serial.available() > 0) // Send data only when you receive data:
   {
      data = Serial.read();   //Read the incoming data & store into data

      Serial.print(data);     //Print Value inside data in Serial monitor

      Serial.print("\n");        

      if(data == '1') // Checks whether value of data is equal to 1

         digitalWrite(13, HIGH);   //If value is 1 then LED turns ON

      else if(data == '0')  //  Checks whether value of data is equal to 0

         digitalWrite(13, LOW);    //If value is 0 then LED turns OFF
   }
}

连接链接:https://halckemy.s3.amazonaws.com/uploads/image_file/file/153200/hc-05-LED%20blink%20Circuit.png

注意:上传代码时，从Arduino上拔下蓝牙模块的TX和RX线，上传完成后，将它们连接起来。