Code not running as expected!

Projects Programming
1

Respected members,

I had modified a code that i have attached to this post and the modified code is as written below.

This code is to read a RFID tag using an EM18 RFID module and shows a necessary output.

This code compiles but does not give the necessary output as the original code. Can you kindly point out the mistakes that i have made while modifying it?
Please help.

char tag[] ="1C002492359F";
char input[12];
int count=0;
boolean flag=0;
int led=11;
int led2=8;
void setup()
{
Serial.begin(9600);
pinMode(led, OUTPUT);
pinMode(led2, OUTPUT);
}
void loop()
{
if(Serial.available())
{
count=0;
flag=1;
while(count<12 && flag!=0)
{
input[count] = Serial.read();
if(input[count] == tag[count])
flag=1;
else
flag=0;
++count;
}
if(flag==1)
{
Serial.println("Access Allowed!");
digitalWrite(led2,HIGH);
delay(4000);
digitalWrite(led2,LOW);
}
else
{
Serial.println("Access Denied");
digitalWrite(led,HIGH);
delay(4000);
digitalWrite(led,LOW);
}
for(count=0; count<12; count++)
input[count]= 'F';
}
}

Rfid_em18_real.ino (1018 Bytes)

2 
  if (Serial.available())
  {
    count = 0;
    flag = 1;
    while (count < 12 && flag != 0)
    {
      input[count] = Serial.read();

You check whether there is Serial data available and if there is (it may only be 1 byte) you read from Serial 12 times. Have you tried printing each char as it is received ?

3

The RFID tag contains 12 bytes of data and this is why i have to read from serial 12 times. It is used for comparing with a pre-provided RFID tag number. If the two serial numbers match, the output is shown.

4

Your presented code and the attached code don't seem to match. The attached code

char tag[] ="1C002492359F"; 
char input[12];        
int count = 0;       
boolean flag = 0;    
int led=9;
int led2=8;
void setup()
{
  Serial.begin(9600);   
  pinMode(led, OUTPUT); 
  pinMode(led2, OUTPUT);
}
void loop()
{
  if(Serial.available())
  {
    count = 0; 
    while(Serial.available() && count < 12) 
    {
      input[count] = Serial.read(); 
      count++; 
      delay(5);
    }
    if(count == 12)  
    {
      count =0;
      flag = 1;
      while(count<12)  
      {
        if(input[count]==tag[count])
         flag = 1; 
        else
         flag= 0;                                   
        count++; 
      }
    }
    if(flag == 1)
    {
      Serial.println("Access Allowed!");
      digitalWrite(led2,HIGH);
      delay(4000);
      digitalWrite(led2,LOW);
    }
    else
    {
      Serial.println("Access Denied"); 
      digitalWrite(led,HIGH);
      delay(4000);
      digitalWrite(led,LOW);
    }
    for(count=0; count<12; count++) 
      input[count]= 'F';
    count = 0;
  }
}

So which one do you need comments on? For the above, print the received characters to serial monitor

void loop()
{
  if(Serial.available())
  {
    count = 0; 
    while(Serial.available() && count < 12) 
    {
      input[count] = Serial.read(); 
      Serial.println(input[count]);
      count++; 
      delay(5);
    }
    Serial.print("Receive finished; count = ");
    Serial.println(count);
    ...
    ...

Does it consistently print 12 for the count?

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