Connecting a rs232 to a seven segment display

Discussion in 'The Projects Forum' started by fisantanic, Mar 8, 2010.

  1. fisantanic

    Thread Starter New Member

    Mar 8, 2010
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    hi all,
    i new to microcontrollers
    actually i do not know anything
    but i was told to build a module
    which has input as rs232 and output a 7 segment display
    how do i go about doing it and what ic chips do i use?
     
  2. t06afre

    AAC Fanatic!

    May 11, 2009
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    I guess you have selected a PIC MCU allready, so I will not comment on the MCU. But a common error many beginners do is to not include a RS232 level converter between the MCU and the RS232 device (PC?). A very common circuit for this purpose is a MAX232 variant. Just Google MAX232 for more info.
     
  3. fisantanic

    Thread Starter New Member

    Mar 8, 2010
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    ok then
    according to you im to connect a rs232 to a max232 then to a 7 segment display
    how do i do it?
    ive never studied this before...i dont know a single thing
     
  4. Papabravo

    Expert

    Feb 24, 2006
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    There is a bit more to it than that. Who told you to build this module and why would they have any expectation that you could succeed.
     
  5. beenthere

    Retired Moderator

    Apr 20, 2004
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    I suppose this must be a school assignment? Even if that is not the case, how is it that you are expected to do this with no background?

    You might be able to rig a MAX232 to stuff data into a shift register that feeds a display driver. What would the function of such a construction be? What is sending the data using the RS-232 protocol, why does it do so, and what is to be displayed?
     
  6. t06afre

    AAC Fanatic!

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    We have all been new to technology sometime;) But anyway tell us in some more details what you want to do. Then we will try to help. But we do not do others work or homework assignments in this forum. And such requests are quickly ignored by other members. But those who put in some effort will be rewarded by other members trying to help
     
    Last edited: Mar 9, 2010
  7. Papabravo

    Expert

    Feb 24, 2006
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    The reason I asked was not to impugn your motives, but to ascertain by who and why you would be given a task in those terms. As has been pointed out you may have some difficulty controlling a display with an RS-232 Receiver alone. A shift register is plausible although uninteresting after a short time. A microcontroller is a much more useful and interesting project.
     
  8. fisantanic

    Thread Starter New Member

    Mar 8, 2010
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    i am attached to this company(its part of my school course)
    you see im an electrical and electronics student but am very weak on electronics
    my company told me to build this module and gave me no other background information as to what it is used for and where
    all i know is i need to find an ic chip that can do rs232 input and output 7 segment display
    i have been looking at datasheets for 2 days ready...
    i cant seem to find any
    all i know thus far is rs232 transmit and receive data serially. and the 7 segment is driven parallely
    then i thought of using shift registers but "my boss" say he doesnt want a clock but rather use SIO
    how?
    thanks for all your help
     
  9. blueroomelectronics

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    Jul 22, 2007
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    You'll need to use a microcontroller.
     
  10. Papabravo

    Expert

    Feb 24, 2006
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    How many digits on the 7-segment display?
    What is producing the serial data that you need to display?
    What baudrate and framing is it using?
    When did he say he wanted this?

    Pretty lame of your boss to ask you to do something like that and give you zero support.

    Find a microcontroller with a UART and an SPI Port
    Go to the Maxim website and find the datasheet for the MAX6954
    While you're there look for an appropriate member of the MAX232 family with one transmitter and one receiver.
    And as far as your boss is concerned -- we never had this conversation.
     
  11. fisantanic

    Thread Starter New Member

    Mar 8, 2010
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    now he doesnt want a clock
    he wants a serial in
    i dont get it
    do you?
     
  12. beenthere

    Retired Moderator

    Apr 20, 2004
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    It would prove very beneficial if you could post up all the details about this project.
    This would be a good start.

    Some further explanation about why no clock might be interesting, too.
     
  13. t06afre

    AAC Fanatic!

    May 11, 2009
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    In engineering specifications are very important. And your boss must also be aware of that fact. Another important thing is resources. Without those two things every project is doomed. So I think you should go to your boss and say in a very polite way. That you need more specifications. Then ask him what kind of resources you will have available for this project. But you should also be honest with your boss and tell him that you can not do this project because you do not have needed qualifications yet. I never start on a new project without proper specifications and resources. And I also say no to projects then I feel I do not have the needed qualifications
     
  14. fisantanic

    Thread Starter New Member

    Mar 8, 2010
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    I told my boss "Sir i can't do this project"
    because as you guys said i need to know the all the specifications but the problem is I DO NOT EVEN KNOW what specifications to look out for..for example i dunno baud rate,framing rate,spi port(and never heard of rs232 before this attachment)...
    i have not studied them..all i studied were simple gates like nor,nand,xor flip flops and such and only learned how to program a microcontroller a few months back(so im not really good at it)
    he replied me that as an electronics engineer i should know all these stuff...
    maybe im just plain dumb
    i cant blame my boss actually..all he told me to do was to find an ic chip(and datasheet) to have rs232 as an input and a 7 segment led as an output and i cant do such a simple task like that...
    my boss has agreed to change my work...dunno what is it yet...
    tommorow ill know
    anyways thank you guys for all your help and suggestions...
     
  15. t06afre

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    I do not know of any IC that do such task. It could have been done by a microcontroller and some support circuits.
     
  16. Papabravo

    Expert

    Feb 24, 2006
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    The problem here is that you expected to find a universe that lined up with your bosses expectations. Either he doesn't understand the universe that exists or you were not able to understand his requirements as he stated them. It is unfortunate, because approached in the proper way this could have been a learning experience for both of you. I also agree with t06afre, that the chip you seek does not exist as an off the shelf item. Even if it did you would still have to find a way to get it on a board and test it. This in itself is a non-trivial task that requires some planning and some experience.
     
  17. fisantanic

    Thread Starter New Member

    Mar 8, 2010
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    I can't but keep on ponder on how easily i gave up on this task...
    I have decided to do the study on my own and for the sake of making myself happy i want to finish up this assignment...
    I don't know how to go about studying...I maybe wanna go study on serial ports first..
    any suggestions??anyone who can lead me in the correct path?
    any online books to refer to?
    I am gonna be an engineer..so i gotta learn it the hard way :)...
     
  18. turborx15

    New Member

    Mar 11, 2010
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    thats so nice ......l like it .. thanks
     
  19. Papabravo

    Expert

    Feb 24, 2006
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    There is a book on serial ports by Jan Axelson. She wrote several on USB that are quite good. Check on Amazon for a used copy
    http://www.amazon.com/Serial-Port-C...=sr_1_1?ie=UTF8&s=books&qid=1268322495&sr=1-1

    BTW I think your decision to give up on this project at this time was the correct decision for both you and your boss.
     
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