Retrieving information from RFID card using Ardunio












0















I'm working on RFID attendance management system using Arduino.

I'm saving the data on the second block on Arduino. The only data I'm saving is "1".



Here's my code:



void setup() {

    Serial.begin(9600);        

    SPI.begin();               

}



int block=2;



byte blockcontent[16] = {"1"};

//byte blockcontent[16] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};

byte readbackblock[18];



void loop()

{       

    mfrc522.PCD_Init(); 

    for (byte i = 0; i < 6; i++) {

        key.keyByte[i] = 0xFF;

    }



    if ( ! mfrc522.PICC_IsNewCardPresent()) {

        return;

    }



    if ( ! mfrc522.PICC_ReadCardSerial()) {

        return;

    }



    Serial.println("card selected");         

    writeBlock(block, blockcontent);

    readBlock(block, readbackblock);

    Serial.print("read block: ");

    for (int j=0 ; j<16 ; j++)

    {

        Serial.write (readbackblock[j]);

        if(readbackblock[j]=="1"){

            Serial.print("Test completed!!");

        }

    }

    Serial.println("");        

}


My Issue:



I wanted to retrieve the data from the Arduino and do something with it. I know that by using Serial.write (readbackblock[j]) we transmits the ASCII numbers as human-readable characters to the serial monitor ( and I get "1" on the Serial Monitor) but the following if statement is not working.



if(readbackblock[j]=="1"){

    Serial.print("Test completed!!");

}





c++ arduino rfid







share|improve this question

























  • blockcontent is a byte array, readbackblock[j] is a single byte and "1" is a string (a nul terminated char array). You can't compare those with ==.

    – gre_gor
    Nov 21 '18 at 18:06











  • @gre_gor what should I do?

    – ahsan
    Nov 21 '18 at 18:17






  • 1





    @ahsan you should learn about data types. And you should post minimal, but complete code

    – datafiddler
    Nov 22 '18 at 14:54











  • ok I will but how can I retrieve the information from an RDIF card can someone please tell me that

    – ahsan
    Nov 23 '18 at 17:03
















0















I'm working on RFID attendance management system using Arduino.

I'm saving the data on the second block on Arduino. The only data I'm saving is "1".



Here's my code:



void setup() {

    Serial.begin(9600);        

    SPI.begin();               

}



int block=2;



byte blockcontent[16] = {"1"};

//byte blockcontent[16] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};

byte readbackblock[18];



void loop()

{       

    mfrc522.PCD_Init(); 

    for (byte i = 0; i < 6; i++) {

        key.keyByte[i] = 0xFF;

    }



    if ( ! mfrc522.PICC_IsNewCardPresent()) {

        return;

    }



    if ( ! mfrc522.PICC_ReadCardSerial()) {

        return;

    }



    Serial.println("card selected");         

    writeBlock(block, blockcontent);

    readBlock(block, readbackblock);

    Serial.print("read block: ");

    for (int j=0 ; j<16 ; j++)

    {

        Serial.write (readbackblock[j]);

        if(readbackblock[j]=="1"){

            Serial.print("Test completed!!");

        }

    }

    Serial.println("");        

}


My Issue:



I wanted to retrieve the data from the Arduino and do something with it. I know that by using Serial.write (readbackblock[j]) we transmits the ASCII numbers as human-readable characters to the serial monitor ( and I get "1" on the Serial Monitor) but the following if statement is not working.



if(readbackblock[j]=="1"){

    Serial.print("Test completed!!");

}





c++ arduino rfid







share|improve this question

























  • blockcontent is a byte array, readbackblock[j] is a single byte and "1" is a string (a nul terminated char array). You can't compare those with ==.

    – gre_gor
    Nov 21 '18 at 18:06











  • @gre_gor what should I do?

    – ahsan
    Nov 21 '18 at 18:17






  • 1





    @ahsan you should learn about data types. And you should post minimal, but complete code

    – datafiddler
    Nov 22 '18 at 14:54











  • ok I will but how can I retrieve the information from an RDIF card can someone please tell me that

    – ahsan
    Nov 23 '18 at 17:03














0












0








0








I'm working on RFID attendance management system using Arduino.

I'm saving the data on the second block on Arduino. The only data I'm saving is "1".



Here's my code:



void setup() {

    Serial.begin(9600);        

    SPI.begin();               

}



int block=2;



byte blockcontent[16] = {"1"};

//byte blockcontent[16] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};

byte readbackblock[18];



void loop()

{       

    mfrc522.PCD_Init(); 

    for (byte i = 0; i < 6; i++) {

        key.keyByte[i] = 0xFF;

    }



    if ( ! mfrc522.PICC_IsNewCardPresent()) {

        return;

    }



    if ( ! mfrc522.PICC_ReadCardSerial()) {

        return;

    }



    Serial.println("card selected");         

    writeBlock(block, blockcontent);

    readBlock(block, readbackblock);

    Serial.print("read block: ");

    for (int j=0 ; j<16 ; j++)

    {

        Serial.write (readbackblock[j]);

        if(readbackblock[j]=="1"){

            Serial.print("Test completed!!");

        }

    }

    Serial.println("");        

}


My Issue:



I wanted to retrieve the data from the Arduino and do something with it. I know that by using Serial.write (readbackblock[j]) we transmits the ASCII numbers as human-readable characters to the serial monitor ( and I get "1" on the Serial Monitor) but the following if statement is not working.



if(readbackblock[j]=="1"){

    Serial.print("Test completed!!");

}





c++ arduino rfid







share|improve this question
















I'm working on RFID attendance management system using Arduino.

I'm saving the data on the second block on Arduino. The only data I'm saving is "1".



Here's my code:



void setup() {

    Serial.begin(9600);        

    SPI.begin();               

}



int block=2;



byte blockcontent[16] = {"1"};

//byte blockcontent[16] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};

byte readbackblock[18];



void loop()

{       

    mfrc522.PCD_Init(); 

    for (byte i = 0; i < 6; i++) {

        key.keyByte[i] = 0xFF;

    }



    if ( ! mfrc522.PICC_IsNewCardPresent()) {

        return;

    }



    if ( ! mfrc522.PICC_ReadCardSerial()) {

        return;

    }



    Serial.println("card selected");         

    writeBlock(block, blockcontent);

    readBlock(block, readbackblock);

    Serial.print("read block: ");

    for (int j=0 ; j<16 ; j++)

    {

        Serial.write (readbackblock[j]);

        if(readbackblock[j]=="1"){

            Serial.print("Test completed!!");

        }

    }

    Serial.println("");        

}


My Issue:



I wanted to retrieve the data from the Arduino and do something with it. I know that by using Serial.write (readbackblock[j]) we transmits the ASCII numbers as human-readable characters to the serial monitor ( and I get "1" on the Serial Monitor) but the following if statement is not working.



if(readbackblock[j]=="1"){

    Serial.print("Test completed!!");

}





c++ arduino rfid




c++ arduino rfid






share|improve this question















share|improve this question













share|improve this question




share|improve this question








edited Nov 21 '18 at 18:10









gre_gor

4,17592631




4,17592631










asked Nov 21 '18 at 17:41









ahsanahsan

75




75













  • blockcontent is a byte array, readbackblock[j] is a single byte and "1" is a string (a nul terminated char array). You can't compare those with ==.

    – gre_gor
    Nov 21 '18 at 18:06











  • @gre_gor what should I do?

    – ahsan
    Nov 21 '18 at 18:17






  • 1





    @ahsan you should learn about data types. And you should post minimal, but complete code

    – datafiddler
    Nov 22 '18 at 14:54











  • ok I will but how can I retrieve the information from an RDIF card can someone please tell me that

    – ahsan
    Nov 23 '18 at 17:03



















  • blockcontent is a byte array, readbackblock[j] is a single byte and "1" is a string (a nul terminated char array). You can't compare those with ==.

    – gre_gor
    Nov 21 '18 at 18:06











  • @gre_gor what should I do?

    – ahsan
    Nov 21 '18 at 18:17






  • 1





    @ahsan you should learn about data types. And you should post minimal, but complete code

    – datafiddler
    Nov 22 '18 at 14:54











  • ok I will but how can I retrieve the information from an RDIF card can someone please tell me that

    – ahsan
    Nov 23 '18 at 17:03

















blockcontent is a byte array, readbackblock[j] is a single byte and "1" is a string (a nul terminated char array). You can't compare those with ==.

– gre_gor
Nov 21 '18 at 18:06





blockcontent is a byte array, readbackblock[j] is a single byte and "1" is a string (a nul terminated char array). You can't compare those with ==.

– gre_gor
Nov 21 '18 at 18:06













@gre_gor what should I do?

– ahsan
Nov 21 '18 at 18:17





@gre_gor what should I do?

– ahsan
Nov 21 '18 at 18:17




1




1





@ahsan you should learn about data types. And you should post minimal, but complete code

– datafiddler
Nov 22 '18 at 14:54





@ahsan you should learn about data types. And you should post minimal, but complete code

– datafiddler
Nov 22 '18 at 14:54













ok I will but how can I retrieve the information from an RDIF card can someone please tell me that

– ahsan
Nov 23 '18 at 17:03





ok I will but how can I retrieve the information from an RDIF card can someone please tell me that

– ahsan
Nov 23 '18 at 17:03












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