Re: Have a question about Arduino? Ask me!

At: Re: Have a question about Arduino? Ask me!

> Thanks for the code man....those two lines really helped...

Glad to hear it!

> now I am facing a new problem...when I am trying to display the larger of the two counts its displaying the correct value but it keeps on displaying it line after line...

The loop() function is special in Arduino. You aren't allowed to return from it because there's nowhere

to return to. You can probably figure out a workaround. Maybe put all your code as a normal loop in

the setup() function, or use an empty infinite loop in place of returning from loop().

e14 Contributor over 12 years ago

Hi there..I am trying out a simple program of matching RFID tags..however it is showing wrong tag even when I am holding up the right one...wat am I doig wrong...the code is posted below...somebody please help...thanksin advance...

int count = 0; // A variable to count the length of the Tag DATA
char tag[]="19729083";
char input[10];
boolean flag=0;
boolean state=0;
void setup()
{
Serial.begin(9600); // Initialize Serial Communication - Both with the RFID reader & the Serial Monitor

}

void loop()
{

if(Serial.available()) // Check if there is Incoming Data in the Serial Buffer. This is data coming from the RFID reader
{
    count = 0; // Reset count to zero
    while(Serial.available() && count<10) // Keep reading Byte by Byte from the Buffer till the Buffer is empty
    {
      input[count] = Serial.read(); // Read 1 Byte of data and store it in the input[] variable
      count++; // increment counter
      delay(5);
    }

    Serial.println(input);//it is displaying the exact number that I stored,even then its showing wrong tag
    Serial.println(count);

    if(count ==10)// When the counter reaches 12 (the size of the ID) we stop and compare each value of the input[] to the corresponding stored value
    {
      count =0; // reset counter varibale to 0
      flag = 1;
      while(count<10 && flag !=0) // Iterate through each value and compare till either the 12 values are all matching or till the first mistmatch occurs
      {
        if(input[count]==tag[count])
        flag = 1; // everytime the values match, we set the flag variable to 1
        else
        flag=0; // if the ID values don't match, set flag variable to 0 and stop comparing by exiting the while loop
        count++; // increment i
      }
    }
        if(flag == 1) // If flag variable is 1, then it means the tags match
    {
      Serial.println("Matched!");
          }
    else
    {
      Serial.println("Wrong Tag"); // Incorrect Tag Message
    }

    for(count=0; count<10; count++) // Fill the input variable array with a fixed value 'F' to overwrite all values getting it empty for the next read cycle
      {
        input[count]= 'F';
      }
     count = 0; // Reset counter variable
}
}
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