Arduino不通过串行接收数据

Question

我正在尝试使用jssc与arduino进行Java通信。仅出于测试目的，我试图直接在Arduino上接收数据并将其发送回PC。问题是，董事会似乎没有收到。当arduino可以发送的代码可以正常工作时，但是却无法接收任何数据。我首先认为问题是jssc，所以我将应用程序更改为Processing，同样的问题。我什至尝试更换板子，没有区别，板子还不错，它可以与Arduino Serial Monitor正常通讯。所以我的问题必须是Java和Processing代码。我知道这是一个非常简单的问题，对此我感到posting愧，这肯定是过去的一个非常简单的问题。

另外一件事，完全没有显示错误

Java代码：

public class ArduinoTest{
    public static void main(String[] args) throws SerialPortException, InterruptedException {
        SerialPort serialPort = new SerialPort("COM6");
        serialPort.openPort();
        serialPort.setParams(SerialPort.BAUDRATE_9600,
                SerialPort.DATABITS_8,
                SerialPort.STOPBITS_1,
                SerialPort.PARITY_NONE);
        int i;
        serialPort.writeBytes("a".getBytes());
        while(true){
            a=serialPort.readBytes(1);
            i = a[0] & 0xff;
            System.out.println(i);
        }
    }
}

处理代码：

import processing.serial.*;

Serial port;
int r;
void setup(){
  port = new Serial(this, "COM6", 9600);
  port.write(1);
}
void draw(){
  if(port.available()>0){
    r = port.read();
    println(r);
  }
}

Arduino代码：

int r1=0;

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

void loop() {
  if(Serial.available() > 0){
    r1 = Serial.read();
    Serial.write(r1);
  }
}

Answer 1

这里是Arduino的有效通信代码：

const int led_pin = 13;    // Initializing the LED pin internal led
String char_output = "";   // Declaring a variable for output


void setup ( ) {
  pinMode(led_pin, OUTPUT); // Declaring the LED pin as output pin
  Serial.begin(9600);       // Starting the serial communication at 9600 baud rate

}

void loop ( ) {


  if (Serial.available ( ) > 0) {   // Checking if the Processing IDE has send a value or not

    char state = Serial.read ( );    // Reading the data received and saving in the state variable

    if (state == '1')  {          // If received data is '1', then turn on LED
      digitalWrite (led_pin, HIGH);
      char_output = "Led on";
    }

    if (state == '0') {     // If received data is '0', then turn off led
      digitalWrite (led_pin, LOW);
      char_output = "Led off";
    }
  }

  delay(50);
  Serial.println (char_output);     // Sending the output to Processing IDE
} 

这里是处理部分：

import processing.serial.*;    // Importing the serial library to communicate with the Arduino

Serial myPort;      // Initializing a vairable named 'myPort' for serial communication
float background_color ;   // Variable for changing the background color

void setup ( ) {
  size (500,  500);     // Size of the serial window, you can increase or decrease as you want
  myPort  =  new Serial (this, "COM3",  9600); // Set the com port and the baud rate according to the Arduino IDE
  myPort.bufferUntil ( '\n' );   // Receiving the data from the Arduino IDE

}
void serialEvent  (Serial myPort) {
  background_color  =  float (myPort.readStringUntil ( '\n' ) ) ;  // Changing the background color according to received data
}

void draw ( ) {
  background ( 150, 50, background_color );   // Initial background color, when we will open the serial window
  if ( mousePressed  &&  ( mouseButton  ==  LEFT ) ) { // if the left mouse button is pressed
    myPort.write ( '1' ) ;       // send a '1' to the Arduino IDE
  }
  if  ( mousePressed  &&  ( mouseButton == RIGHT ) ) {  // if the right mouse button is pressed
    myPort.write ( '0' ) ;     // Send a '0' to the Arduino IDE
  }
}

阅读注释，看到从串行读取和打印到串行分离