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multiple 28140 rfid readers problem with reading — Parallax Forums

multiple 28140 rfid readers problem with reading

TrickyTractorTrickyTractor Posts: 4
in Accessories
Hi,

I'm working on a program that uses multiple rfid readers at different locations to read rfid tags. I'm running into the problem that i can't get the two readers to work on one arduino mega or on two separate arduino unos. On the mega they work separately but as soon as i put in the 'enable' of the other reader it stops the reading for both of them. Here's my code for the mega, I would really appreciate your help :)

Greetings

Comments

  • TrickyTractorTrickyTractor Posts: 4 
    int  val = 0;
char code[10];
int bytesread = 0;
int i = 0;
int myNum[10];
unsigned long int multArray[] = {1, 1, 268435456, 16777216, 1048576,
                                 65536, 4096, 256, 16, 1
                                };
unsigned long int trueTag = 0;
int countYellowW = 0;
int countGreenW = 0;
int countRedW = 0;
int countYellowC = 0;
int countGreenC = 0;
int countRedC = 0;


void setup() {
  // initialize both serial ports:
  Serial.begin(2400);
  Serial1.begin(2400);

  pinMode(2, OUTPUT);                          // Set digital pin 2 as OUTPUT to connect it to the RFID /ENABLE pin
  digitalWrite(2, LOW);                        // Activate the RFID reader
  pinMode(3, OUTPUT);                          // Set digital pin 3 as OUTPUT to connect it to the RFID /ENABLE pin
  digitalWrite(3, LOW);                        // Activate the RFID
}

void loop() {
  if (Serial.available() > 0) {                // if data available from reader
    if ((val = Serial.read()) == 10) {         // check for header
      bytesread = 0;
      while (bytesread < 10) {                 // read 10 digit code
        if ( Serial.available() > 0) {
          val = Serial.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
        code[0] = 48;                          //Zero out the first two elements of the code array
        code[1] = 48;
        //Cycle through the code array and create int elements in myNum
        for (i = 0; i < 10; i++)
        {
          if (code[i] == '0')                  //I am not a programmer, but this is the only way I could
            myNum[i] = 0;
          else if (code[i] == '1')             //find to convert elements of a char array to ints...
            myNum[i] = 1;
          else if (code[i] == '2')
            myNum[i] = 2;
          else if (code[i] == '3')
            myNum[i] = 3;
          else if (code[i] == '4')
            myNum[i] = 4;
          else if (code[i] == '5')
            myNum[i] = 5;
          else if (code[i] == '6')
            myNum[i] = 6;
          else if (code[i] == '7')
            myNum[i] = 7;
          else if (code[i] == '8')
            myNum[i] = 8;
          else if (code[i] == '9')
            myNum[i] = 9;
          else if (code[i] == 'A')
            myNum[i] = 10;
          else if (code[i] == 'B')
            myNum[i] = 11;
          else if (code[i] == 'C')
            myNum[i] = 12;
          else if (code[i] == 'D')
            myNum[i] = 13;
          else if (code[i] == 'E')
            myNum[i] = 14;
          else if (code[i] == 'F')
            myNum[i] = 15;
          else
            myNum[i] = 9999;                       //Oops! an error
        }
        //With trueTag initialized to 0, create the true tag number by summing trueTag with each element of the
        //integer myNum array multiplied by the corresponding element of the multArray.
        for (i = 0; i < 10; i++)
        {
          trueTag = trueTag + (myNum[i] * multArray[i]);
        }
        if (trueTag == 3372093) {

          countYellowC++;
          if (countYellowC % 2 == 0) {
            Serial.print(3);
          }
          else {
            Serial.print(2);
          }
        }
        else if (trueTag == 3375172) {

          countGreenC++;
          if (countGreenC % 2 == 0) {
            Serial.print(9);
          }
          else {
            Serial.print(8);
          }
        }
        else if (trueTag == 3369475) {

          countRedC++;
          if (countRedC % 2 == 0) {
            Serial.print(6);
          }
          else {
            Serial.print(5);
          }
        }
      }
      bytesread = 0;
      trueTag = 0;                                 //Zero out trueTag for next iteration of the loop
      digitalWrite(2, HIGH);                       //deactivate the RFID reader for a moment so it will not flood
      delay(2500);                                 //wait for a bit
      digitalWrite(2, LOW);                        //Activate the RFID reader
    }
  } else if (Serial1.available() > 0) {
    if ((val = Serial1.read()) == 10) {         // check for header
      bytesread = 0;
      while (bytesread < 10) {                 // read 10 digit code
        if ( Serial1.available() > 0) {
          val = Serial1.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
        code[0] = 48;                          //Zero out the first two elements of the code array
        code[1] = 48;
        //Cycle through the code array and create int elements in myNum
        for (i = 0; i < 10; i++)
        {
          if (code[i] == '0')                  //I am not a programmer, but this is the only way I could
            myNum[i] = 0;
          else if (code[i] == '1')             //find to convert elements of a char array to ints...
            myNum[i] = 1;
          else if (code[i] == '2')
            myNum[i] = 2;
          else if (code[i] == '3')
            myNum[i] = 3;
          else if (code[i] == '4')
            myNum[i] = 4;
          else if (code[i] == '5')
            myNum[i] = 5;
          else if (code[i] == '6')
            myNum[i] = 6;
          else if (code[i] == '7')
            myNum[i] = 7;
          else if (code[i] == '8')
            myNum[i] = 8;
          else if (code[i] == '9')
            myNum[i] = 9;
          else if (code[i] == 'A')
            myNum[i] = 10;
          else if (code[i] == 'B')
            myNum[i] = 11;
          else if (code[i] == 'C')
            myNum[i] = 12;
          else if (code[i] == 'D')
            myNum[i] = 13;
          else if (code[i] == 'E')
            myNum[i] = 14;
          else if (code[i] == 'F')
            myNum[i] = 15;
          else
            myNum[i] = 9999;                       //Oops! an error
        }
        //With trueTag initialized to 0, create the true tag number by summing trueTag with each element of the
        //integer myNum array multiplied by the corresponding element of the multArray.
        for (i = 0; i < 10; i++)
        {
          trueTag = trueTag + (myNum[i] * multArray[i]);
        }
        if (trueTag == 3372093) {

          countYellowW++;
          if (countYellowW % 2 == 0) {
            Serial.print(2);
          }
          else {
            Serial.print(1);
          }
        }
        else if (trueTag == 3375172) {

          countGreenW++;
          if (countGreenW % 2 == 0) {
            Serial.print(8);
          }
          else {
            Serial.print(7);
          }
        }
        else if (trueTag == 3369475) {

          countRedW++;
          if (countRedW % 2 == 0) {
            Serial.print(4);
          }
          else {
            Serial.print(6);
          }
        }
      }
      bytesread = 0;
      trueTag = 0;                                 //Zero out trueTag for next iteration of the loop
      digitalWrite(3, HIGH);                       //deactivate the RFID reader for a moment so it will not flood
      delay(2500);                                 //wait for a bit
      digitalWrite(3, LOW);                        //Activate the RFID reader
    }
  }
}
  • DaveJensonDaveJenson Posts: 375
    (You might try asking your question on an Arduino forum...)
  • TrickyTractorTrickyTractor Posts: 4
    yeah, tried that, but didn't help much yet
  • DaveJensonDaveJenson Posts: 375
    In the ELSE clause, should you be using

    Serial1.print

    ?
  • TrickyTractorTrickyTractor Posts: 4
    i think so, yes, since i want the two rfid readers to send different digits when the same tag is read
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