Arduino Mega Hardware Serial

Troager · ‎04-02-2013

Hello Fellas.

i asked this question in another thread about software serial, but i think this deserves a new thread because its hardware serial on the mega

i have been working with my Arduino Mega and the serial connections, but having a hard time figuring this thing out.

The devices im using is an Arduino Mega 2560 and an ID12/20 RFID Reader. (i want the reader to be on serial3).

and so far i tried to modify LVIFA Interface.ino and heres my code:

//RFID Variables
//-------------------------------------
byte valRfid = 0;
byte i = 0;
byte codeTag[6];
byte checksum = 0;
byte tempbyte = 0;
//-------------------------------------
/******************************************************************************* **
** NEW COMMAND(RFID)
******************************************************************************** */
      case 0x35: // RFID Packet
      if (Serial3.available() > 0) {
        if((valRfid = Serial3.read()) == 2) {        // check for header
          incommingByte = Serial3.read();
          while (incommingByte < 12) {               // read 10 digit code + 2 digit checksum
            if( Serial3.available() > 0) {
          valRfid = Serial3.read();
          if((valRfid == 0x0D)||(valRfid == 0x0A)||(valRfid == 0x03)||(valRfid == 0x02)) { // if header or stop bytes before the 10 digit reading
            break;                                    // stop reading
          }
          // Do Ascii/Hex conversion:
          if ((valRfid >= '0') && (valRfid <= '9')) {
            valRfid = valRfid - '0';
          } else if ((valRfid >= 'A') && (valRfid <= 'F')) {
            valRfid = 10 + valRfid - 'A';
          }
           // Every two hex-digits, add byte to code:
          if (incommingByte & 1 == 1) {
            // make some space for this hex-digit by
            // shifting the previous hex-digit with 4 bits to the left:
            codeTag[incommingByte >> 1] = (valRfid | (tempbyte << 4));
            if (incommingByte >> 1 != 5) {                // If we're at the checksum byte,
              checksum ^= codeTag[incommingByte >> 1];       // Calculate the checksum... (XOR)
            };
          } else {
            tempbyte = valRfid;                           // Store the first hex digit first...
          };
          incommingByte++;                                // ready to read next digit
        }
      }
     // Output to Serial:
      if (incommingByte == 12) {                          // if 12 digit read is complete
        Serial.print("5-byte code: ");
        for (i=0; i<5; i++) {
          if (codeTag < 16) Serial.print("0");
          Serial.print(codeTag, HEX);
          Serial.print(" ");
        }
        Serial.println();
        Serial.print("Checksum: ");
        Serial.print(codeTag[5], HEX);
        Serial.println(codeTag[5] == checksum ? " -- passed." : " -- error.");
        Serial.println();
        }
      incommingByte = 0;
        }
      }
       break;

Right after the IR Case (expanding the case structure)

and i made an edit in syncLV:

void syncLV()
{
Serial.begin(DEFAULTBAUDRATE);
Serial3.begin(DEFAULTBAUDRATE);
i2cReadTimeouts = 0;
spiBytesSent = 0;
spiBytesToSend = 0;
Serial3.flush();
Serial.flush();
}

Plus in unknown packet

    /****************************************************************************** ***
    ** Unknown Packet
    ******************************************************************************* **/
    default:      // Default Case
      Serial.flush();
      Serial3.flush();
      break;
    }
}
else{
    // Checksum Failed, Flush Serial Buffer
    Serial.flush();
    Serial3.flush();
}

So anything i should consider or anything i can do in my firmware, and what can i do in labview to read it ?

i attached my LabVIEWInterface.ino if the you wanna check and see if i did it correctly.

Thanks in advance.

- Thomas R.

LabVIEW Interface for Arduino Discussions

Arduino Mega Hardware Serial

Arduino Mega Hardware Serial