Loading ...
Sorry, an error occurred while loading the content.

Re: UART is transmitting grabage on the hyper-terminal screen

Expand Messages
  • fourier902000
    ... I am sorry about my english!! when I type a character from the keyboard what I see is some other character which is different from the keystroke that
    Message 1 of 5 , Aug 28, 2008
    • 0 Attachment
      --- In booksbybibin@yahoogroups.com, "Mihai Galos" <mihaigalos@...> wrote:
      >
      > Dear fourier,
      > Please explain yourself using more words because your english
      > prevents us from understanding you.
      >
      > Such an UART behaviour as i think you are trying to describe at 1)
      > can be caused by :
      >
      > - capacitor values inconsistent with the datashhet for the max232
      > (or equivalanet) TTL to EIA sinal converter (you are using one, RIGHT
      > ?!)
      > - high noise environment
      > - uncalibrated bit rates (refer to setting bit rates in the AVR
      > datasheet)
      >
      > Kind regards,
      > Mihai GALOS
      >
      > --- In booksbybibin@yahoogroups.com,
      > "fourier902000" <fourier902000@> wrote:
      > >
      > > Hello
      > > I'am in the process of writing a Uart code that is intended to read
      > > sensor values and out those values a PC screen.
      > >
      > > However the first part of the process is completed, code run and
      > > compile but one thing ...
      > >
      > > 1) if a letter is typed from the keyboard I don't see the correct
      > > output. Meaning if A is pressed on the keyboard B is output on the
      > > screen.
      > >
      > > 2) The second part of my project is to take values from the A/D
      > > registers and displayed those values on the Hyperteminal.( any idea
      > > how to go about this ?)
      > >










      I am sorry about my english!!


      when I type a character from the keyboard what I see is some other
      character which is different from the keystroke that was depressed .

      How do you set the internal clock ?
      >
    • Mihai Galos
      Fourier, The clock for the UART is actualy the bit rate. See the chapter Examples of Baud Rate Setting in you microcontoller s datasheet. For example, for
      Message 2 of 5 , Aug 29, 2008
      • 0 Attachment
        Fourier,
        The clock for the UART is actualy the bit rate. See the chapter
        "Examples of Baud Rate Setting" in you microcontoller's datasheet.
        For example, for atmega48 running at 1Mhz(default) for a 4800bps data
        rate, set UBRR to 12. (U2xn bit is 0).

        When you say you hit a key and another character writes on the
        terminal, you give no info about the hardware you are using:

        1)What type of microcontroller?
        2)What is the wireing of the UART pins ?
        3)Are you using the max232 EIA to TTL voltage level converter?
        4)If so, are you using the correctly sized capacitors for this?

        We cannot help you unless you take some time and write in a lot more
        words the problems you are experiences and the hardware you are using.

        For further reading, see
        http://mihaigalos.ro/work/Embedded/Simple/UART/readOn.html
        (entire URL might contain spaces, delete any spaces and copy paste in
        browser).

        Kind regards,
        Mihai GALOS.


        --- In booksbybibin@yahoogroups.com,
        "fourier902000" <fourier902000@...> wrote:
        >
        > --- In booksbybibin@yahoogroups.com, "Mihai Galos" <mihaigalos@>
        wrote:
        > >
        > > Dear fourier,
        > > Please explain yourself using more words because your english
        > > prevents us from understanding you.
        > >
        > > Such an UART behaviour as i think you are trying to describe at
        1)
        > > can be caused by :
        > >
        > > - capacitor values inconsistent with the datashhet for the
        max232
        > > (or equivalanet) TTL to EIA sinal converter (you are using one,
        RIGHT
        > > ?!)
        > > - high noise environment
        > > - uncalibrated bit rates (refer to setting bit rates in the AVR
        > > datasheet)
        > >
        > > Kind regards,
        > > Mihai GALOS
        > >
        > > --- In booksbybibin@yahoogroups.com,
        > > "fourier902000" <fourier902000@> wrote:
        > > >
        > > > Hello
        > > > I'am in the process of writing a Uart code that is intended to
        read
        > > > sensor values and out those values a PC screen.
        > > >
        > > > However the first part of the process is completed, code run
        and
        > > > compile but one thing ...
        > > >
        > > > 1) if a letter is typed from the keyboard I don't see the
        correct
        > > > output. Meaning if A is pressed on the keyboard B is output on
        the
        > > > screen.
        > > >
        > > > 2) The second part of my project is to take values from the A/
        D
        > > > registers and displayed those values on the Hyperteminal.( any
        idea
        > > > how to go about this ?)
        > > >
        >
        >
        >
        >
        >
        >
        >
        >
        >
        >
        > I am sorry about my english!!
        >
        >
        > when I type a character from the keyboard what I see is some
        other
        > character which is different from the keystroke that was depressed
        .
        >
        > How do you set the internal clock ?
        > >
        >
      Your message has been successfully submitted and would be delivered to recipients shortly.