First of all, I am a beginner with Arduino. I have a circuit consisting of: an Arduino Uno, an RFID RC522 card reader and the sender from an RF 433 MHz module.
I am trying to transmit the ID code of the RFID card with the RF 433MHz sender, but it does not work. First, I am reading the card and then I compose in one string the RFID code, for example "18016518623564".
With the code below, I cannot read the RFID card. (Nothing is seen on the serial monitor.) It seems to be a problem with vw_setup(2000);. If I comment it out, I can read the code one time. If I comment out also vw_wait_tx();, I can read the code twice. If I comment out also send("1");, I can read the code an unlimited number of times. But, whatever I do, nothing can be sent (the program stops at vw_wait_tx();).
Could please someone help me to solve the problem and be able to send the RFID code to the receiver?
Below is the code:
// includes for RFID
#include <SPI.h>
#include <RFID.h>
// includes for RF communication
#include <VirtualWire.h>
// defines for RFID
#define SS_PIN 10
#define RST_PIN 5
// variables for RFID
RFID rfid(SS_PIN, RST_PIN);
int serNum[5]; // array to store the RFID code
String rfid_string; // variable to store the concatenated card identifier
void setup() {
Serial.begin(9600);
SPI.begin();
rfid.init();
// initialize the IO and ISR for RF
vw_setup(2000); // Bits per sec
}
void loop() {
read_and_compose_rfid_code(); // read and compose the rfid code into one string
send("1"); // send 1 throug RF - just for testing
delay(1000);
}
void read_and_compose_rfid_code (void) {
if (rfid.isCard()) {
// check if rfid card is present nearby to the sensor antenna
if (rfid.readCardSerial()) {
// read card identifier into array defined in RFID class
// concatenate the card identifier as one string
rfid_string = String(rfid.serNum[0]) + String(rfid.serNum[1]) + String(rfid.serNum[2]) + String(rfid.serNum[3]) + String(rfid.serNum[4]);
Serial.print(rfid_string); // test to see if the code is properly composed
Serial.println();
}
rfid.halt();
delay(1000); // set a delay of 1 second before the next card read
}
}
/* function used to send the card identifier through RF */
void send (char *message) {
vw_send((uint8_t *)message, strlen(message));
// "message" is an array of the bytes to send, and strlen(message) is the number of bytes stored in the array
vw_wait_tx(); // wait until the whole message has been transmitted
}
