各位rs485的問題

sing6625

各位大哥大姐，小弟我在用arduino r3 和傳感擴充模組

DFR088，我要用rs485讀取表頭ctec713p裡面的資料，要怎樣寫？
這是我改了點的程式碼，請各位幫幫忙指點一下～～～
看看我的問題在那裡~~~~

#include <SoftwareSerial.h>

#define rxPin 2

#define txPin 3

#define ledPin 13

// set up a soft serial port

SoftwareSerial mySerial(rxPin, txPin);

int  val = 0;
char code[10];
int bytesread = 0;

void setup() {
  // define pin modes for tx, rx, led pins:

  pinMode(rxPin, INPUT);    // Set rxPin as INPUT to accept SOUT from RFID pin

  pinMode(txPin, OUTPUT);   // Set txPin as OUTPUT to connect it to the RFID /ENABLE pin

  pinMode(ledPin, OUTPUT);  // Let the user know whats up

  // set the data rate for the serial ports

  mySerial.begin(2400);    // RFID reader SOUT pin connected to Serial RX pin at 2400bps

  Serial.begin(9600);      // Serial feedback for debugging in Wiring

  // say something

  Serial.println("0203 009C");

}

void loop() {
  digitalWrite(txPin, LOW);           // Activate the RFID reader

  digitalWrite(ledPin, LOW);          // Turn off debug LED

   

  if((val = mySerial.read()) == 10) { // check for header
    bytesread = 0;
   
    while(bytesread<10) {             // read 10 digit code
      val = mySerial.read();
      

      if((val == 10)||(val == 13)) {  // if header or stop bytes before the 10 digit reading
        break;                        // stop reading
      }
      

      code[bytesread] = val;          // add the digit           

      bytesread++;                    // ready to read next digit  

    }
   
    if(bytesread == 10) {             // If 10 digit read is complete
      digitalWrite(txPin, HIGH);      // deactivate RFID reader
      digitalWrite(ledPin, HIGH);     // activate LED to show an RFID card was read

//      Serial.print("TAG code is: ");  // possibly a good TAG
      Serial.println(code);           // print the TAG code

    }
   
    bytesread = 0;
    delay(2000);                      // wait for a second to read next tag

  }
}