Hello guys, I was recently working on a project which i saw on yt.
I got all the components and the necessary things to run but when I am running the code that have been given by the youtuber, I am facing error.
The code is given below.(The project title is RFID based attendance system, with esp32 devkit v1)
//>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> 01_Test_RFID-RC522_Serial
// This code only takes the UID in string form.
// If you want to see more detailed information about an RFID card or keychain, please run the program code "DumpInfo".
// The "DumpInfo" program code is located at :
// Library folder "MFRC522" -> "examples" folder -> "DumpInfo" folder -> DumpInfo.ino
// or
// From Arduino IDE : File -> Examples -> MFRC522 -> DumpInfo
// or
// From Arduino IDE : File -> Examples -> INCOMPATIBLE-> MFRC522 -> DumpInfo
//----------------------------------------Including the libraries.
#include <SPI.h>
#include <MFRC522.h>
//----------------------------------------
// Defines SS/SDA PIN and Reset PIN for RFID-RC522.
#define SS_PIN 5
#define RST_PIN 4
// Variable to read data from RFID-RC522.
int readsuccess;
char str[32] = "";
String UID_Result = "";
// Create MFRC522 object as "mfrc522" and set SS/SDA PIN and Reset PIN.
MFRC522 mfrc522(SS_PIN, RST_PIN);
//________________________________________________________________________________getUID()
// Subroutine to obtain UID/ID when RFID card or RFID keychain is tapped to RFID-RC522 module.
int getUID() {
if(!mfrc522.PICC_IsNewCardPresent()) {
return 0;
}
if(!mfrc522.PICC_ReadCardSerial()) {
return 0;
}
byteArray_to_string(mfrc522.uid.uidByte, mfrc522.uid.size, str);
UID_Result = str;
mfrc522.PICC_HaltA();
mfrc522.PCD_StopCrypto1();
return 1;
}
//________________________________________________________________________________
//________________________________________________________________________________byteArray_to_string()
void byteArray_to_string(byte array[], unsigned int len, char buffer[]) {
for (unsigned int i = 0; i < len; i++) {
byte nib1 = (array[i] >> 4) & 0x0F;
byte nib2 = (array[i] >> 0) & 0x0F;
buffer[i*2+0] = nib1 < 0xA ? '0' + nib1 : 'A' + nib1 - 0xA;
buffer[i*2+1] = nib2 < 0xA ? '0' + nib2 : 'A' + nib2 - 0xA;
}
buffer[len*2] = '\0';
}
//________________________________________________________________________________
//________________________________________________________________________________VOID SETUP()
void setup(){
// put your setup code here, to run once:
Serial.begin(115200);
Serial.println();
delay(1000);
// Init SPI bus.
SPI.begin();
// Init MFRC522.
mfrc522.PCD_Init();
delay(1000);
Serial.println();
Serial.println("Please tap your card or key chain to the RFID-RC522 module.");
}
//________________________________________________________________________________
//________________________________________________________________________________VOID LOOP()
void loop(){
// put your main code here, to run repeatedly:
readsuccess = getUID();
if(readsuccess){
Serial.println();
Serial.print("UID : ");
Serial.println(UID_Result);
delay(500);
}
delay(10);
}
//________________________________________________________________________________
//<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
The error i get is.
C:\Users\sugan\Documents\Arduino\libraries\MFRC522\src\MFRC522Extended.cpp: In member function 'MFRC522::StatusCode MFRC522Extended::TCL_Transceive(TagInfo*, byte*, byte, byte*, byte*)':
C:\Users\sugan\Documents\Arduino\libraries\MFRC522\src\MFRC522Extended.cpp:824:34: error: ordered comparison of pointer with integer zero ('byte*' {aka 'unsigned char*'} and 'int')
824 | if (backData && (backLen > 0)) {
| ~~~~~~^
C:\Users\sugan\Documents\Arduino\libraries\MFRC522\src\MFRC522Extended.cpp:847:42: error: ordered comparison of pointer with integer zero ('byte*' {aka 'unsigned char*'} and 'int')
847 | if (backData && (backLen > 0)) {
| ~~~~~~^
exit status 1
Compilation error: exit status 1
