Void as an int?

this void prints rfid value on lcd screen;
     

code: [select]

void dump_byte_array(byte *buffer, byte buffersize) {   
        (byte x=0; x < buffersize; x++){
        lcd.print(buffer[x] < 16 ? "0" :""); //value cannot bigger 16 digits
          lcd.print(buffer[x], hex);
    }
       }

when include void in loop();
     

code: [select]

dump_byte_array(mfrc522.uid.uidbyte, mfrc522.uid.size);
its that, wanna store value gives out int. can make name tags each rfid card. ex;

code: [select]

if(valueoncard=="81949b75"){
   
    lcd.print("name1");
   
  }else if(valueoncard=="839fa9d5"){
   
    lcd.print("name2");
   
  }else if(dvalueoncard=="938c8f00"){
   
    lcd.print("name3");
   
  }else if(valueoncard=="45e09f2c"){
   
    lcd.print("name4");
   
  }else{
   
    lcd.print("your card has not been entered database. sorry frown emoticon");
  }


hope kinda makes sense. :/

thanks guys!

this looks far, can make print value, want print out names.

code: [select]

#include <spi.h>
#include <mfrc522.h>
#include <liquidcrystal.h>

liquidcrystal lcd (7,6,5,4,3,2);

#define rst_pin         9           // configurable, see typical pin layout above
#define ss_pin          10          // configurable, see typical pin layout above
byte id;
mfrc522 mfrc522(ss_pin, rst_pin);   // create mfrc522 instance.

// number of known default keys (hard-coded)
// note: synchronize nr_known_keys define defaultkeys[] array
#define nr_known_keys   8
// known keys, see: https://code.google.com/p/mfcuk/wiki/mifareclassicdefaultkeys
byte knownkeys[nr_known_keys][mfrc522::mf_key_size] =  {
    {0xff, 0xff, 0xff, 0xff, 0xff, 0xff}, // ff ff ff ff ff ff = factory default
    {0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5}, // a0 a1 a2 a3 a4 a5
    {0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5}, // b0 b1 b2 b3 b4 b5
    {0x4d, 0x3a, 0x99, 0xc3, 0x51, 0xdd}, // 4d 3a 99 c3 51 dd
    {0x1a, 0x98, 0x2c, 0x7e, 0x45, 0x9a}, // 1a 98 2c 7e 45 9a
    {0xd3, 0xf7, 0xd3, 0xf7, 0xd3, 0xf7}, // d3 f7 d3 f7 d3 f7
    {0xaa, 0xbb, 0xcc, 0xdd, 0xee, 0xff}, // aa bb cc dd ee ff
    {0x00, 0x00, 0x00, 0x00, 0x00, 0x00}  // 00 00 00 00 00 00
};

/*
 * initialize.
 */
void setup() {
  lcd.begin(16, 2);
    lcd.print("scan card");
    lcd.setcursor(0,2);
    serial.begin(9600);         // initialize serial communications pc
    while (!serial);            // nothing if no serial port opened (added arduinos based on atmega32u4)
    spi.begin();                // init spi bus
    mfrc522.pcd_init();         // init mfrc522 card
    serial.println(f("try used default keys print block 0 of mifare picc."));
}

/*
 * helper routine dump byte array hex values serial.
 */
void dump_byte_array(byte *buffer, byte buffersize) {   
 for (byte x=0; x < buffersize; x++){
        lcd.print(buffer[x] < 16 ? "0" :"");
        lcd.print(buffer[x], hex);
 }
}

void uids(){
  //you need find way turn value int
  //you've tried including void , such.
  if(dump_byte_array(mfrc522.uid.uidbyte, mfrc522.uid.size)=="81949b75"){
   
    lcd.print("name1");
   
  }else if(dump_byte_array(mfrc522.uid.uidbyte, mfrc522.uid.size)=="839fa9d5"){
   
    lcd.print("name2");
   
  }else if(dump_byte_array(mfrc522.uid.uidbyte, mfrc522.uid.size)=="938c8f00"){
   
    lcd.print("name3");
   
  }else if(dump_byte_array(mfrc522.uid.uidbyte, mfrc522.uid.size)=="45e09f2c"){
   
    lcd.print("name4");
   
  }else{
   
    lcd.print("your card has not been entered database. sorry frown emoticon");
  }
 
}
*/
void dump_byte_array1(byte *buffer, byte buffersize) {
    (byte = 0; < buffersize; i++) {
        //serial.print(buffer[i] < 0x10 ? " 0" : " ");
        serial.print(buffer[i] < 16 ? "0" : "");
        //serial.print(buffer[i], hex);
    }
}

/*
 * try using picc (the tag/card) given key access block 0.
 * on success, show key details, , dump block data on serial.
 *
 * @return true when given key worked, false otherwise.
 */
boolean try_key(mfrc522::mifare_key *key)
{
    boolean result = false;
    byte buffer[18];
    byte block = 0;
    byte status;
   
    // serial.println(f("authenticating using key a..."));
    status = mfrc522.pcd_authenticate(mfrc522::picc_cmd_mf_auth_key_a, block, key, &(mfrc522.uid));
    if (status != mfrc522::status_ok) {
        // serial.print(f("pcd_authenticate() failed: "));
        // serial.println(mfrc522.getstatuscodename(status));
        return false;
    }

    // read block
    byte bytecount = sizeof(buffer);
    status = mfrc522.mifare_read(block, buffer, &bytecount);
    if (status != mfrc522::status_ok) {
        // serial.print(f("mifare_read() failed: "));
        // serial.println(mfrc522.getstatuscodename(status));
    }
    else {
        // successful read
        result = true;
        dump_byte_array((*key).keybyte, mfrc522::mf_key_size);
        serial.println();
        // dump block data
        serial.print(f("block ")); lcd.print(block); serial.print(f(":"));
        dump_byte_array(buffer, 16);
        serial.println();
    }
    serial.println();

    mfrc522.picc_halta();       // halt picc
    mfrc522.pcd_stopcrypto1();  // stop encryption on pcd
    return result;
}

/*
 * main loop.
 */
void loop() {
    // new cards
    if ( ! mfrc522.picc_isnewcardpresent())
        return;

    // select 1 of cards
    if ( ! mfrc522.picc_readcardserial())
        return;

    // show details of picc (that is: tag/card)
serial.print(f("card uid:"));
dump_byte_array1(mfrc522.uid.uidbyte, mfrc522.uid.size);
    dump_byte_array(mfrc522.uid.uidbyte, mfrc522.uid.size);
    delay(1000);
    lcd.clear();
    lcd.print("scan card");
    lcd.setcursor(0,2);
    //lcd.clear();
    serial.println();
 
}

"void" return type of function , means nothing returned program segment calls function.

"dump_byte_array(byte *buffer, byte buffersize)" function, not void.

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