Unwanted characters received during serial transmission

[dhk]

Hello,

I am reading the data from the rfid reader via Arduino Mega and sending it to pc.
But when the data is read by the pc, in the end some unwanted characters appear(mostly smileys). I have defined an array of 15 but when I use strlen function to check the length of the data received, then it shows 16.
Also sometimes the data coming will be of 31 characters with the same data being appended at the end.


Can someone please explain why is this problem occuring?

 

[milan.rajik]

My RFID card gives data continuously if kept near the reader.

 

[hobbyckts]

What is the voltage level of your RFID reader and at what distance between your reader has been placed.