RFID

Forum 2005-2010 (read only) Software Syntax & Programs
#1

Hello all,

I copied some code from the arduino playground that worked just fine to take the code from my rfid tag. But when i try to use the data to compare it to already stored data it does nothing.

Here is the code

// RFID reader for Arduino 
// Wiring version by BARRAGAN 
// Modified for Arudino by djmatic


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

void setup() { 

Serial.begin(2400); // RFID reader SOUT pin connected to Serial RX pin at 2400bps 
pinMode(2,OUTPUT);   // Set digital pin 2 as OUTPUT to connect it to the RFID /ENABLE pin 
digitalWrite(2, LOW);                  // Activate the RFID reader
}  


 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 
      Serial.println(code);
      

[center]THIS IS WHERE IT DOES NOT WORK[/center]
      if (code == "3600290C6D") {
      Serial.println("Welcome, Alan");
          }
          
      if (code == "0F03028718") {
      Serial.println("Welcome, Oli");
         }
      
      bytesread = 0; 
           delay(500);                       // wait for a second 
    } 
  } 
} 
}


// extra stuff
// digitalWrite(2, HIGH);             // deactivate RFID reader

everything compiles but even with the right card it does not print “Hello, Alan”

any ideas would be greatly appreciated, Thank you!

#2

code is an array of characters. The array does not have an equality operator, so

      if (code == "3600290C6D") {

will never work. If code were a NULL-terminated array (it is not), you could use

      if (strcmp(code,"3600290C6D")) {

But, you will have to do it the hard way:

char good[] = "3600290C6D";
boolean match = true;
for(int i=0; i<10; i++)
{
   if(code[i] != good[i])
   {
      match = false;
      break;
   }
}

if(match)
   // They are the same
#3