Shop OBEX P1 Docs P2 Docs Learn Events
Help in reading rfid tags correctly — Parallax Forums

Help in reading rfid tags correctly

ju_lee_oju_lee_o Posts: 2
edited 2011-04-29 06:41 in Accessories
Hello to all,

new to this forum and I really really need some help using the Parallax reader. I'm trying to display the tag's ID on an LCD using a an atmel micro-controller. I am able to receive the data from the reader but when I try to display the tag's ID on the LCD all I get is garbage. So I'm guessing my problem is in interpreting the data with the micro-controller?

If anybody could help with more info on how the Parallax reader sends the info. According to the data sheet it sends a 12-byte ascii string via the TTL so I'm assuming i can store each byte in a char array using a for loop. I've seen some codes online that do this and get the tag's ID without problems but are using a different RFID reader.

So any info and suggestions will be greatly appreciated THANKS!!!!

I'm using the ATMEGA32 micro-controller and the Serial Parallax Reader
running with a baudrate of 2400 and the MCU frequency at 8MHz

Comments

  • FranklinFranklin Posts: 4,747
    edited 2011-04-27 12:26
    . I am able to receive the data from the reader
    How do you know? Try displaying the data to a PC for testing or make sure what you get from the tag is correct (how I don't know but it is your circuit)
  • Mike GreenMike Green Posts: 23,101
    edited 2011-04-27 12:43
    There really isn't any more information than that provided in the reader's datasheet. The information on page 3 provides it all. We can't help you with the ATMEGA programming nor the debugging. If you have specific questions about what the information in the datasheet means, please ask, but the burden is on you to create a program that will receive and interpret what the RFID reader is documented to send.
  • ju_lee_oju_lee_o Posts: 2
    edited 2011-04-29 03:14
    @ Franklin, Yeah i got all the tag's ID from a hyperterminal using a PC first to make sure I was getting the correct data to display on the LCD

    @ Mike, Well actually i wanted to know if you could give me a bit more in depth info on how the reader sends the info to micro-controller. I know it states on the datasheet that it sends a 12-byte ascii string, so I'm guessing it will send e.g. $0A, $30, $46, $36, $38, $40, $43, $65, $30, $34, $46, $0D right?
  • Mike GreenMike Green Posts: 23,101
    edited 2011-04-29 06:41
    Right. There's no "in depth info" involved. If you're asking how an RFID reader works, here's one description I found on a simple Google search.
Sign In or Register to comment.