thanks to all of you for the reply.
I found the solution.
after looking at the code and some debugging.
my code is working fine now.
This is the code
/**
* --------------------------------------------------------------------------------------------------------------------
* Example sketch/program showing how to read data from more than one PICC to serial.
* --------------------------------------------------------------------------------------------------------------------
* This is a MFRC522 library example; for further details and other examples see: https://github.com/miguelbalboa/rfid
*
* Example sketch/program showing how to read data from more than one PICC (that is: a RFID Tag or Card) using a
* MFRC522 based RFID Reader on the Arduino SPI interface.
*
* Warning: This may not work! Multiple devices at one SPI are difficult and cause many trouble!! Engineering skill
* and knowledge are required!
*
* @license Released into the public domain.
*
* Typical pin layout used:
* -----------------------------------------------------------------------------------------
* 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 1 SDA(SS) ** custom, take a unused pin, only HIGH/LOW required **
* SPI SS 2 SDA(SS) ** custom, take a unused pin, only HIGH/LOW required **
* 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>
#include <nRF24L01.h>
#include <RF24.h>
RF24 radio(7, 8); // CE, CSN
const byte add[6] = "00001";
#define RST_PIN 9 // Configurable, see typical pin layout above
#define SS_PIN 10 // Configurable, take a unused pin, only HIGH/LOW required, must be diffrent to SS 2
//#define SS_2_PIN 8 // Configurable, take a unused pin, only HIGH/LOW required, must be diffrent to SS 1
#define NR_OF_READERS 1
byte ssPins[] = {SS_PIN};
MFRC522 mfrc522[NR_OF_READERS]; // Create MFRC522 instance.
/**
* Initialize.
*/
void setup() {
Serial.begin(9600); // Initialize serial communications with the PC
while (!Serial); // Do nothing if no serial port is opened (added for Arduinos based on ATMEGA32U4)
SPI.begin(); // Init SPI bus
for (uint8_t reader = 0; reader < NR_OF_READERS; reader++) {
mfrc522[reader].PCD_Init(ssPins[reader], RST_PIN); // Init each MFRC522 card
Serial.print(F("Reader "));
Serial.print(reader);
Serial.print(F(": "));
mfrc522[reader].PCD_DumpVersionToSerial();
}
radio.begin();
radio.openWritingPipe(add);
radio.setPALevel(RF24_PA_MAX);
radio.stopListening();
}
/**
* Main loop.
*/
void loop() {
for (uint8_t reader = 0; reader < NR_OF_READERS; reader++) {
// Look for new cards
if (mfrc522[reader].PICC_IsNewCardPresent() && mfrc522[reader].PICC_ReadCardSerial()) {
Serial.print(F("Reader "));
Serial.print(reader);
// Show some details of the PICC (that is: the tag/card)
Serial.print(F(": Card UID:"));
dump_byte_array(mfrc522[reader].uid.uidByte, mfrc522[reader].uid.size);
Serial.println();
mfrc522[reader].PCD_StopCrypto1();
}
}
}
/**
* Helper routine to dump a byte array as hex values to Serial.
*/
void dump_byte_array(byte *buffer, byte bufferSize) {
int c[]={176,240,158,94};
int count=0;
delay(10);
for (byte i = 0; i < bufferSize; i++) {
delay(10);
Serial.print(buffer[i] < 0x10 ? " 0" : " ");
Serial.print(buffer[i], HEX);
}
Serial.println();
for (byte i = 0; i < bufferSize; i++) {
if(buffer[i]==c[i]){
count++;
}
}
int flag=0;
if(count==4){
const char text[] = "17624015894";
radio.write(&text, sizeof(text));
}else{
const char text[] = "No";
radio.write(&text, sizeof(text));
}
}
void before() {
// Make sure MFRC is disabled from the SPI bus
pinMode(RST_PIN, INPUT);
digitalWrite(RST_PIN, HIGH);
pinMode(SS_PIN, OUTPUT);
digitalWrite(SS_PIN, LOW);
}