Getting UID from RC522 blocks code

Projects Programming
1

I'm making a little parking lot, which includes mostly opening a servo motor using either keypad, bluetooth(hc-05) and freshly added, Rfid(RC522)
I cant get inputs from other sources if i want to get the UID from the rfid. meaning when I added the only piece of code that I found that returns the UID it seems to block all the void loop() hence all the other inputs/code dont work.
Heres the full code:

#include <Servo.h>          //Servo Motor
#include <SoftwareSerial.h>//Bluetooth functions library:HC05 IS SUPERIOR!
#include "TM1637.h"        //4 digit display functions library
#include <SPI.h>
#include <MFRC522.h>
//Credit to Baroryan

//copyright (c)*/
const int rs = 38, en = 39, d4 = 36 ,d5 = 37, d6 = 41, d7 = 40;//Defining LCD PINS
const int DA=31, D0=30,D1=33,D2=32,D3=35;//Defining KEYPAD data PINS
const int servoPin=43,buzzer=42,rx=53,tx=52;//Defining(By order): servo pin, buzzer pin, 4DD pins, and bluetooth pins(rx tx)
//buzzer pin is 36!
//,CLK=34,DIO=35

#define SS_PIN 45
#define RST_PIN 44
int count = 0;
int cnt=0;//this cnt is used later on to make sure all 5 chars are equal.
int cnt2=0;//used for switch case to count how many chars were already received
int cnt3=0;
char c=0;//this is where we place the char received from the user

char password[5] = {'8', '5', '2', '0', '#'};
char keysPressed[5] = "";
char keys[5]="";

byte customChar2[] = {
  B00000,
  B00000,
  B01010,
  B00000,
  B10001,
  B01110,
  B00000,
  B00000
};


byte customChar[] = {//Custom Char for lcd screen, in this case; a heart.  
  0x00,
  0x00,
  0x0A,
  0x1F,
  0x1F,
  0x0E,
  0x04,
  0x00
};
//  #define DA 25 Used to define Keypad pins and other misc using #Define which talks to the processor->
//  #define D0 24  ->decided to use const int instead.
//  #define D1 27
//  #define D2 26
//  #define D3 29
//  #define servoPin 37
//  #define buzzer 36
//  #define CLK 34 
//  #define DIO 35
void lcdSetup();
void gateOpenSequence();
void returnKey(int key);
void wrongPassword();
void Beep();
SoftwareSerial Bluetooth(rx,tx);//intialize bluetooth to pins
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);//intialize LCD to pins
MFRC522 mfrc522(SS_PIN, RST_PIN);   // Create MFRC522 instance.
Servo servo;//intialize servo
byte nuidPICC[4];


void printHex(byte *buffer, byte bufferSize) {
  for (byte i = 0; i < bufferSize; i++) {
    Serial.print(buffer[i] < 0x10 ? " 0" : " ");
    Serial.print(buffer[i], HEX);
  }
}

void setup()
{
  Serial.begin(9600);
  Bluetooth.begin(9600);
  SPI.begin();      // Initiate  SPI bus
  pinMode(DA ,INPUT);
  pinMode(D0 ,INPUT);
  pinMode(D1 ,INPUT);
  pinMode(D2,INPUT);
  pinMode(D3,INPUT);
  mfrc522.PCD_Init();   // Initiate MFRC522
  lcd.begin(20,4);
  lcdSetup();//Self Created function that turns lcd to our preffered default screen "Home screen"
  servo.attach(servoPin);
  servo.write(5);
  pinMode(buzzer,OUTPUT);
  digitalWrite(buzzer, HIGH); 
  delay(200);          
  digitalWrite(buzzer, LOW);
  Bluetooth.print("Enter 1 to open the gate!");//Write to user bluetooth terminal instructions
  lcd.createChar(2, customChar2);
  lcd.createChar(1, customChar);
}

void loop()
{


  if (!mfrc522.PICC_IsNewCardPresent()) 
  {
    return;
  }
  //Select one of the cards
  if (!mfrc522.PICC_ReadCardSerial()) 
  {
    return;
  }
  //Show UID on serial monitor
  Serial.print("UID tag :");
  String content= "";
  byte letter;

  for (byte i = 0; i < mfrc522.uid.size; i++) 
  {
     Serial.print(mfrc522.uid.uidByte[i] < 0x10 ? " 0" : " ");
     Serial.print(mfrc522.uid.uidByte[i], HEX);
     content.concat(String(mfrc522.uid.uidByte[i] < 0x10 ? " 0" : " "));
     content.concat(String(mfrc522.uid.uidByte[i], HEX));
  }
  Serial.println();
  Serial.print("Message : ");
  content.toUpperCase();
  if (content.substring(1) == "17 27 C7 A6" || "BA FA 21 28") //change here the UID of the card/cards that you want to give access
  {
    Serial.println("Authorized access");
    Serial.println();
    delay(3000);
  }
 
 else   {
    Serial.println(" Access denied");
    delay(3000);
  }
  
  char Data=Bluetooth.read();//Recieves Data from bluetooth and places it in variable 'Data'
  if(Data=='1'){//if data from bluetooth equals to 1(1 recieved from bluetooth IS NOT an integer, it is a char.)
    gateOpenSequence();//Self created function that executes all actions when Gate need to be opened.
  }
  while(digitalRead(DA)==1){         //While recieving characters from keypad.
    int key =digitalRead(D3)*8 + digitalRead(D2)*4 +digitalRead(D1)*2 + digitalRead(D0);//Certain formula used to decipher what key has been pressed
    returnKey(key);//Self created function that translates key deciphered to keypad layout. puts key pressed into variable 'c'
    Serial.print(c);
    if(c!='D') keys[cnt3]=c;
      
    switch(cnt2){
      case 0:
        if(c!='D'){
          lcd.clear();
          lcd.setCursor(9, 0);
          lcd.print(keys[cnt3]);
          ++cnt3;
          ++cnt2;
          Beep();
          break;
        }
        else break;
      case 1:
        if(c!='D'){
          lcd.setCursor(8,0);
          lcd.print("*");
          lcd.print(keys[cnt3]);
          ++cnt3;
          ++cnt2;
          Beep();
          break;
        }
        else{
          lcd.clear();
          --cnt3;
          --cnt2;
          break;
        }

      case 2:
        if(c!='D'){
          lcd.setCursor(8, 0);
          lcd.print("**");
          lcd.print(keys[cnt3]);
          ++cnt2;
          ++cnt3;
          Beep();
          break;
        }
        else{
          lcd.clear();
          lcd.setCursor(9,0);
          cnt3--;
          cnt2--;
          lcd.print(keys[cnt3-1]);
          
          
          break;
        }

      case 3:
        if(c!='D'){
          lcd.setCursor(8, 0);
          lcd.print("***");
          lcd.print(keys[cnt3]);
          ++cnt2;
          ++cnt3;
          Beep();
          break;
        }
        else{
          lcd.clear();
          lcd.setCursor(9,0);
          lcd.print("*");
          cnt3--;
          cnt2--;
          lcd.print(keys[cnt3-1]);
          break;
        }
      case 4:
        if(c!='D'){
          cnt2=0;
          cnt3=0;
        }
        else{
          lcd.clear();
          lcd.setCursor(9, 0);
          lcd.print("**");
          cnt2--;
          cnt3--;
          lcd.print(keys[cnt3-1]); 
        }
      break;
    }
    while(digitalRead(DA)==1);//Making sure we wont get double input from one press, forcing the loop to stay there as long as a key is pressed
    if(c!='D'){
      keysPressed[count] = c;//Placing key pressed into an array
      count++;//raising array index
    }
    else{
      keysPressed[count]="";
      count--;      
     }
    if (count == 5)//when count reaches 5, meaning array is full check if array 'password' is equal to the 5 keys the user just entered.
    {
      for (int i = 0; i < 5; i++)
      {
        if (password[i] == keysPressed[i])//if keys are the same add one to cnt, if cnt equals to 5, it means all keys were the same
        {
          cnt++;
        }
      }
        if(cnt==5){
          gateOpenSequence();
          cnt=0;
        }
        else{
          wrongPassword();
          cnt=0;
        }
        }
      }
  }


void returnKey(int key)
{ 
  char arrkey[16]={ '1','2','3','A','4','5','6','B','7','8','9','C','*','0','#','D' };
  c=arrkey[key];
  
}

void lcdSetup(){
  lcd.setCursor(0,0);
  lcd.write(2);
  lcd.setCursor(1, 0);
  lcd.write(1);
  lcd.setCursor(18,0);
  lcd.write(1);
  lcd.setCursor(19,0);
  lcd.write(2);
  lcd.setCursor(2,0);
  lcd.print("----Welcome-----");
  lcd.setCursor(0,1);
  lcd.print("|  Enter password  |");
  lcd.setCursor(0,2);
  lcd.print("|and then press '#'|");
  lcd.setCursor(0, 3);
  lcd.print("|------------------|");
}
void gateOpenSequence(){
  int start = 0;
  int desired = 105;
  lcd.clear();
  lcd.setCursor(6,0);
  lcd.print("Welcome");
  lcd.setCursor(8,1);
  lcd.print("Home");
  count = 0;
  digitalWrite(buzzer,HIGH);
  while(start<desired){
  servo.write(++start);
  delay(10);
  }
  delay(1000);
  digitalWrite(buzzer,LOW);
  lcdSetup();
  while(start>5){
  servo.write(--start);
  delay(10);
  }


}
void wrongPassword(){
  lcd.clear();
  lcd.setCursor(7,0);
  lcd.print("Wrong");
  lcd.setCursor(6,1);
  lcd.print("Password");
  lcd.setCursor(4, 2);
  lcd.print("Achalta ota");
  count = 0;
  for(int jj=0;jj<3;jj++){
    Beep();
  }
  delay(2000);
  lcdSetup();

}

void Beep(){
  digitalWrite(buzzer,HIGH);
  delay(200);
  digitalWrite(buzzer,LOW);
  delay(200);
}

I will really appreciate in help as I cant seem to find any explanations about this two functions:

if (!mfrc522.PICC_IsNewCardPresent()) 
  {
    return;
  }
  //Select one of the cards
  if (!mfrc522.PICC_ReadCardSerial()) 
  {
    return;
  }

Thanks in advance,
Barzy.

2

Its what you have written in your code.

If no card is present, return.
means it should start the loop from top.

You have to give your program a better structure and give other things a chance to be executed even if no card was presented.

For example you could put such things before the two if's.

I assume the next problem is your while .
This could block again.

My proposal is you come up with a clear program flow on a chart - then we can discuss how to make the code better.

3

I have found a better piece of code that does not block my code, and works absolutely perfect when runs alone, for some reason when I implement it into my code it doesn't work at all, in fact it seems the functions themselves just stopped working, as the one that did work but blocked the code doesn't work anymore(still blocks the code). Adding the bits of code.

Rfid code that doesnt block and works:

#include <SPI.h>
#include <MFRC522.h>

#define SS_PIN 45
#define RST_PIN 44

MFRC522 mfrc522(SS_PIN, RST_PIN);

void setup() {
  Serial.begin(9600); 
  SPI.begin(); 
  mfrc522.PCD_Init(); 
  Serial.println("Ready to read UID");
}

void loop() {
  if (mfrc522.PICC_IsNewCardPresent() && mfrc522.PICC_ReadCardSerial()) {
    byte buffer[4];
    for (byte i = 0; i < 4; i++) {
      buffer[i] = mfrc522.uid.uidByte[i];
    }
    mfrc522.PICC_HaltA();
    Serial.print("UID: ");
    for (byte i = 0; i < 4; i++) {
      Serial.print(buffer[i], HEX);
      Serial.print(" ");
    }
    Serial.println();
    if (buffer[0] == 0x17 && buffer[1] == 0x27 && buffer[2] == 0xC7 && buffer[3] == 0xA6) {
      Serial.println("Good job");
    }
  }
}

Should I send my full code with it implemented as well?(It replaces in the same location the last code.)
Thanks a lot for the reply anyway!

4

as already written, my opinion is that your first code is not well structured.

If I where you - I would start from scratch. Code #3 seems to be a better start.

But I would start with a sheet of paper and draw a flow chart. Afterwards an implementation should be easy.

5

Problem is, I tried to make a flow chart and came to the same conclusion that, all 3 systems gotta work at the same time, meaning all of their input codes just have to work on the same loop at any order it seems

6

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