The writing code is from the MFRC522 Example below:
I have added an array to store the value but it does not store it as the same value written to it in the writing. instead it stores it as byte values. I am fairly new so would appreciate any help.
/*
* Write personal data of a MIFARE RFID card using a RFID-RC522 reader
* Uses MFRC522 - Library to use ARDUINO RFID MODULE KIT 13.56 MHZ WITH TAGS SPI W AND R BY COOQROBOT.
* -----------------------------------------------------------------------------------------
* MFRC522 Arduino Arduino Arduino Arduino Arduino
* Reader/PCD Uno/101 Mega Nano v3 Leonardo/Micro Pro Micro
* Signal Pin Pin Pin Pin Pin Pin
* -----------------------------------------------------------------------------------------
* RST/Reset RST 9 5 D9 RESET/ICSP-5 RST
* SPI SS SDA(SS) 10 53 D10 10 10
* SPI MOSI MOSI 11 / ICSP-4 51 D11 ICSP-4 16
* SPI MISO MISO 12 / ICSP-1 50 D12 ICSP-1 14
* SPI SCK SCK 13 / ICSP-3 52 D13 ICSP-3 15
*
* Hardware required:
* Arduino
* PCD (Proximity Coupling Device): NXP MFRC522 Contactless Reader IC
* PICC (Proximity Integrated Circuit Card): A card or tag using the ISO 14443A interface, eg Mifare or NTAG203.
* The reader can be found on eBay for around 5 dollars. Search for "mf-rc522" on ebay.com.
*/
#include <SPI.h>
#include <MFRC522.h>
#define RST_PIN 9 // Configurable, see typical pin layout above
#define SS_PIN 10 // Configurable, see typical pin layout above
MFRC522 mfrc522(SS_PIN, RST_PIN); // Create MFRC522 instance
void setup() {
Serial.begin(9600); // Initialize serial communications with the PC
SPI.begin(); // Init SPI bus
mfrc522.PCD_Init(); // Init MFRC522 card
Serial.println(F("Write personal data on a MIFARE PICC "));
}
void loop() {
// Prepare key - all keys are set to FFFFFFFFFFFFh at chip delivery from the factory.
MFRC522::MIFARE_Key key;
for (byte i = 0; i < 6; i++) key.keyByte[i] = 0xFF;
// Reset the loop if no new card present on the sensor/reader. This saves the entire process when idle.
if ( ! mfrc522.PICC_IsNewCardPresent()) {
return;
}
// Select one of the cards
if ( ! mfrc522.PICC_ReadCardSerial()) {
return;
}
byte buffer[34];
byte block;
MFRC522::StatusCode status;
byte len;
Serial.setTimeout(20000L) ; // wait until 20 seconds for input from serial
// Ask personal data: Family name
Serial.println(F("Enter the weight, ending with#"));
len = Serial.readBytesUntil('#', (char *) buffer, 30) ; // read family name from serial
for (byte i = len; i < 30; i++) buffer[i] = ' '; // pad with spaces
block = 1;
//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;
}
else Serial.println(F("PCD_Authenticate() success: "));
// Write block
status = mfrc522.MIFARE_Write(block, buffer, 16);
if (status != MFRC522::STATUS_OK) {
Serial.print(F("MIFARE_Write() failed: "));
Serial.println(mfrc522.GetStatusCodeName(status));
return;
}
else Serial.println(F("MIFARE_Write() success: "));
}
and the reading code is :
/*
* Initial Author: ryand1011 (https://github.com/ryand1011)
*
* Reads data written by a program such as "rfid_write_personal_data.ino"
*
* See: https://github.com/miguelbalboa/rfid/tree/master/examples/rfid_write_personal_data
*
* Uses MIFARE RFID card using RFID-RC522 reader
* Uses MFRC522 - Library
* -----------------------------------------------------------------------------------------
* MFRC522 Arduino Arduino Arduino Arduino Arduino
* Reader/PCD Uno/101 Mega Nano v3 Leonardo/Micro Pro Micro
* Signal Pin Pin Pin Pin Pin Pin
* -----------------------------------------------------------------------------------------
* RST/Reset RST 9 5 D9 RESET/ICSP-5 RST
* SPI SS SDA(SS) 10 53 D10 10 10
* SPI MOSI MOSI 11 / ICSP-4 51 D11 ICSP-4 16
* SPI MISO MISO 12 / ICSP-1 50 D12 ICSP-1 14
* SPI SCK SCK 13 / ICSP-3 52 D13 ICSP-3 15
*/
#include <SPI.h>
#include <MFRC522.h>
#define RST_PIN 9 // Configurable, see typical pin layout above
#define SS_PIN 10 // Configurable, see typical pin layout above
MFRC522 mfrc522(SS_PIN, RST_PIN); // Create MFRC522 instance
int weightArray[2];
int counter = 0;
//*****************************************************************************************//
void setup() {
Serial.begin(9600); // Initialize serial communications with the PC
SPI.begin(); // Init SPI bus
mfrc522.PCD_Init(); // Init MFRC522 card
Serial.println(F("Read personal data on a MIFARE PICC:")); //shows in serial that it is ready to read
}
//*****************************************************************************************//
void loop() {
// Prepare key - all keys are set to FFFFFFFFFFFFh at chip delivery from the factory.
MFRC522::MIFARE_Key key;
for (byte i = 0; i < 6; i++) key.keyByte[i] = 0xFF;
//some variables we need
byte block;
byte len;
MFRC522::StatusCode status;
//-------------------------------------------
// Reset the loop if no new card present on the sensor/reader. This saves the entire process when idle.
if ( ! mfrc522.PICC_IsNewCardPresent()) {
return;
}
// Select one of the cards
if ( ! mfrc522.PICC_ReadCardSerial()) {
return;
}
Serial.println("Detected");
byte buffer1[18];
block = 4;
len = 18;
//------------------------------------------- GET FIRST NAME
status = mfrc522.PCD_Authenticate(MFRC522::PICC_CMD_MF_AUTH_KEY_A, 4, &key, &(mfrc522.uid)); //line 834 of MFRC522.cpp file
if (status != MFRC522::STATUS_OK) {
Serial.print(F("Authentication failed: "));
Serial.println(mfrc522.GetStatusCodeName(status));
return;
}
status = mfrc522.MIFARE_Read(block, buffer1, &len);
if (status != MFRC522::STATUS_OK) {
Serial.print(F("Reading failed: "));
Serial.println(mfrc522.GetStatusCodeName(status));
return;
}
//PRINT FIRST NAME
/* for (uint8_t i = 0; i < 16; i++)
{
if (buffer1[i] != 32)
{
Serial.write(buffer1[i]);
}
}
Serial.print(" ");
*/
//---------------------------------------- GET LAST NAME
byte buffer2[18];
block = 1;
status = mfrc522.PCD_Authenticate(MFRC522::PICC_CMD_MF_AUTH_KEY_A, 1, &key, &(mfrc522.uid)); //line 834
if (status != MFRC522::STATUS_OK) {
Serial.print(F("Authentication failed: "));
Serial.println(mfrc522.GetStatusCodeName(status));
return;
}
status = mfrc522.MIFARE_Read(block, buffer2, &len);
if (status != MFRC522::STATUS_OK) {
Serial.print(F("Reading failed: "));
Serial.println(mfrc522.GetStatusCodeName(status));
return;
}
//PRINT LAST NAME
for (uint8_t i = 0; i < 16; i++) {
Serial.write(buffer2[i]);
}
for(int i = 0; i < sizeof(weightArray) / sizeof(weightArray[1]); i++) {
Serial.print(weightArray[i]);
}
counter++;
Serial.println(F("\n**End Reading**\n"));
delay(1000); //change value if you want to read cards faster
mfrc522.PICC_HaltA();
mfrc522.PCD_StopCrypto1();
}
//*****************************************************************************************//
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