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Start-Byte, Stop-Byte Issue — Parallax Forums

Start-Byte, Stop-Byte Issue

Hi everyone,

currently I am working with the 28140 in my company, and trying to read rfid-cards ( 2.12" 3.37") with a beaglebone black.
I can read informations from the card, but they dont fit to the datasheet of the 28140. It should be a ASCII-string of 12 bytes that starts with 0x0A and ends with 0x0D, but the string that I get looks like "01018749A0".
Maybe I have to reverse the string, but I dont see the 0D and have only 10 bytes either.
Maybe someone has an idea?!
Thanks very much for your help.

eyk107

Comments

  • Heater.Heater. Posts: 21,230
    edited 2016-08-03 09:11
    0x0a is line feed
    0x0d is carriage return

    These are non-printable characters so you won't see anything as a string.

    If that is the string, in ASCII, you get back then you have 10 characters. Which may well be correct
    Can you dump the received characters in hexadecimal so we can see them all?
  • thank you for your fast reply.
    I thougt, I see something like 'CR' or something like this. After reading the string as a hex-code, I get the following line:
    0A 30313031383734394130 0D
    Everything looks fine, thank you for your advise
  • Heater.Heater. Posts: 21,230
    Great stuff.
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