RFID CARD ID (if else case)

Projects Programming
1

I try to change the code to recognize certain card numbers. but how to

//int Card1 = 39005A9C88;
//int Card2 = 39005A9C85;

#include <SoftwareSerial.h>
#define STX 2
#define ETX 3

SoftwareSerial softSerial(10, 11); 
int rx_counter;
byte rx_data[14]; // 1+10+2+1

void setup() {
  rx_counter = 0; // init counter
  Serial.begin(9600);
  softSerial.begin(9600);
        Serial.print("online...");

}

void loop() {
  if (softSerial.available() > 0) {
    rx_data[rx_counter] = softSerial.read();
    if (rx_counter == 0 && rx_data[0] != STX) {
      Serial.println("Out of sync!"); // do not increment rx_counter
    } else {
      rx_counter++;
    }
    if (rx_counter >= 14) {
      rx_counter = 0; // reset counter
      if (rx_data[0] == STX && rx_data[13] == ETX) { // packet starts with STX and ends with ETX
        byte calc_checksum = 0;
        for (int i = 0; i < 6; i++) { // data with checksum
          calc_checksum ^= ascii_char_to_num(rx_data[i*2+1]) * 16 + ascii_char_to_num(rx_data[i*2+2]);
        }
        if (calc_checksum == 0) {
          Serial.print("ID: ");
          for (int i = 1; i <= 10; i++) {
            Serial.write(rx_data[i]);
          }
          Serial.println();
        } else {
          Serial.println("Checksum ERROR!");
        }
      } else {
          Serial.println("Incorrect packet!");
      }
    } 
  }
}

byte ascii_char_to_num(byte a) {
  a -= '0'; // 0..9
  if (a > 9) a -= 7; // A..F
  return a;
} 

if card ID == Card1 || Card2  { Serial.print("ON!")} Else {Serial.print("OFF!")}
2 
          Serial.print("ID: ");
          for (int i = 1; i <= 10; i++) {
            Serial.write(rx_data[i]);
          }

What does that actually output?

3 
//int Card1 = 39005A9C88;
//int Card2 = 39005A9C85;
if card ID == Card1 || Card2  { Serial.print("ON!")} Else {Serial.print("OFF!")}

It looks like you may mean something like:

char Card1ID[] = "39005A9C88";
char Card2ID[] = "39005A9C85";

if (strncmp(rx_data+1, Card1ID, 10) == 0 || strncmp(rx_data+1, Card2ID, 10) == 0) {
    Serial.print("ON!");
} else {
    Serial.print("OFF!");
}
4

invalid conversion from 'byte* {aka unsigned char*}' to 'const char*' [-fpermissive] :confused:

#include <SoftwareSerial.h>
#define STX 2
#define ETX 3

SoftwareSerial softSerial(10, 11); // recommended pins for RX on Mega: 10, 11, 12...
int rx_counter;
byte rx_data[14]; // 1+10+2+1

char Card1ID[] = "39005A9C88";
char Card2ID[] = "39005A9C85";


void setup() {
  rx_counter = 0; // init counter
  Serial.begin(9600);
  softSerial.begin(9600);
        Serial.print("online...");

}

void loop() {
  if (softSerial.available() > 0) {
    rx_data[rx_counter] = softSerial.read();
    if (rx_counter == 0 && rx_data[0] != STX) {
      Serial.println("Out of sync!"); // do not increment rx_counter
    } else {
      rx_counter++;
    }
    if (rx_counter >= 14) {
      rx_counter = 0; // reset counter
      if (rx_data[0] == STX && rx_data[13] == ETX) { // packet starts with STX and ends with ETX
        byte calc_checksum = 0;
        for (int i = 0; i < 6; i++) { // data with checksum
          calc_checksum ^= ascii_char_to_num(rx_data[i*2+1]) * 16 + ascii_char_to_num(rx_data[i*2+2]);
        }
        if (calc_checksum == 0) {
          Serial.print("ID: ");
          for (int i = 1; i <= 10; i++) {
            Serial.write(rx_data[i]);
//
            if (strncmp(rx_data+1, Card1ID, 10) == 0 || strncmp(rx_data+1, Card2ID, 10) == 0) {
             Serial.print("ON!");
            } else {
            Serial.print("OFF!");
            }
//            
          }
          Serial.println();
        } else {
          Serial.println("Checksum ERROR!");
        }
      } else {
          Serial.println("Incorrect packet!");
      }
    } 
  }
}


byte ascii_char_to_num(byte a) {
  a -= '0'; // 0..9
  if (a > 9) a -= 7; // A..F
  return a;
}
5 
            if (strncmp(rx_data+1, Card1ID, 10) == 0 || strncmp(rx_data+1, Card2ID, 10) == 0) {

What is the data type of rx_data ?
What is the data type of Card1ID and Card2ID ?

6

int rx_counter;
byte rx_data[14]; // 1+10+2+1

char Card1ID[] = "39005A9C88";
char Card2ID[] = "39005A9C85";

7

It apparently doesn't like you using "unsigned char" in place of "char" when working with characters. If you change rx_data[] from 'byte' to 'char' it works fine.

8

TXNS!

:slight_smile: