which digital circuit should i use?

Discussion in 'Homework Help' started by Blerona, Jan 2, 2015.

  1. Blerona

    Thread Starter New Member

    Jan 2, 2015
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    I need some help to start my project :/ I have to project a circuit that generates ASCII code for my ID. (ex. 141571634)
    For the first combination in input, the circuit will generate the first number of the ID in binary code, then for the second input, the second number of the ID and so on.
    Thank you very much!
     
  2. MikeML

    AAC Fanatic!

    Oct 2, 2009
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    Is this a school project? If so, it should be moved to "homework forum".

    You want to build just one where the ID code is known apriori, or a generic device that can store and generate any one of thousands of codes?

    Is it supposed to transmit the code serially, or 8-bits at a time?

    What techniques are you allowed to use? (Microprocessor, UART chip, discrete gates,)?
     
  3. Blerona

    Thread Starter New Member

    Jan 2, 2015
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    the assignment wasn't given with a lot of explanation and i'm a beginner in this field, i think just one where the ID code is known apriori
     
  4. MikeML

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    To do this project, you will need to learn something about the following list of topics:

    Finite State Machines
    Counters
    Read-only-Memory
    Digital Logic
    Clock Oscillator
    ASCII encoding
    ASCII serial transmission (if required)
    Handshaking

    Tell us what you have studied?
     
  5. Blerona

    Thread Starter New Member

    Jan 2, 2015
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    i am a freshman year, in computer science, we have learned combined circuit so far so it is all about multiplexers, encoders, decoders, demultiplexers, converters etc.
    p.s i'm new in this forum, i'm sorry for my mistakes.
     
  6. ardianlumi

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    Jan 2, 2015
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    We didn't learn, nothing from what you mentioned.
    We learned only basics digital circuits. like : mulitplexer, demultiplexer, encoder, decoder etc.
     
  7. djsfantasi

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    Apr 11, 2010
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    1. Nothing was given about how the digits were to be input? E.g., a keypad or switches.
    2. And how is the result (i.e. the generated ASCII) to be presented or output?
    3. Do you know by now how decimal digits are represented in ASCII? What I mean is what ASCII value represents a 1?
    4. And I am assuming that you know the binary values of the decimal digits are, correct?

    I'm asking these four questions to learn more about your assignment and to what extent your basic understanding is, regarding important concepts central to a solution.

    Edit: Who is asking the question? Blerona or Ardianlumi?
     
  8. GopherT

    AAC Fanatic!

    Nov 23, 2012
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    My logic lessons tell me that you are saying [ (-1)(-1)=1 ] you HAVE learned what was mentioned by @MikeML.
    My gut tells me you meant that you HAVE NOT learned it.
     
  9. ardianlumi

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    Jan 2, 2015
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    Through digital circuits i need this number [141533555] to be converted in ASCII code, i have to say that i dont understand very well what professor asked from our side but i think that, this number [141533555] i should convert to binary code first than i have to work with digital circuits, or there is another way?
    Thank you
     
  10. Blerona

    Thread Starter New Member

    Jan 2, 2015
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    We both have the same assignment.

    Nothing was given about the input, i assume we have to make a combination with binary numbers. The output has to be presented as a binary number, for the first number of the ID ex. 141568799, for number 1 it has to be 0001, for 4 - 0100 and so on.

    I can't ask any question to the professor because everything is part of the assignment.

    We learned about numeric systems, arithmetic operations, Bool Algebra, complement arithmetic, Karnaugh map, combinational circuits and some other that i mentioned earlier.
     
  11. djsfantasi

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    Apr 11, 2010
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    I thought you had to output the ASCII value?

    Where I am going with this is that you should be able to determine a pattern between the binary value of a digit and the ASCII value representing that digit.
    How many bits are needed to encode the digits 0-9? How many bits are there in an ASCII value? What is the difference or similarity between the two?

    Without knowing how you are going to input the digits, there's not much further I can go to direct you.It sounds from your vague description, that you simply have to have the bits of the ASCII value available as your output. But that's a guess. Also, based on your answer to my other questions, I have something in mind... but it's irrelevant without knowing how you are going to input the digits (or their values).

    Ardianlumi: I don't think it is practical to convert the entire ID to binary.
     
  12. WBahn

    Moderator

    Mar 31, 2012
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    As others have touched on, the specs are lacking.

    What do you mean by "the first combination in input"?

    What are your inputs? Are they the four-bit BCD encoding of a digit? Is the ID supposed to be hardcoded? What?

    As djsfantasi suggested, look at the possible digits and the ASCII codes that represent them. You should notice a VERY simple way of generating the latter from the former.
     
  13. MikeML

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    Seems to me that you need to build a black box. The Box has some number of inputs, and some number of outputs.

    From what you have posted, you seem to understand that there will be eight outputs, one each for each bit of the ASCII code. Some of those bits might never change.

    How many inputs are required and what do they do?

    One idea might be to have two inputs; call them A and B.
    A might be a signal to the black box that the user is asking for the first character of the code.
    B might be a signal to the black box that the user is asking for each subsequent character.

    This idea requires that the black box contain a counter (state machine) which keeps track of which character is to be output (first, second, third, etc). The sequence of outputing the characters can be restarted at any time by the order that A and B are asserted.

    A totally different approach would be to have four inputs coded as an address of which character the box is supposed to output, 0000=first, 0001=second, ... 1001=ninth(and last).

    There are probably a hundred ways to make this work. Now that I have provided a way of thinking about the problem, why don't you propose something?
     
  14. shteii01

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    Feb 19, 2010
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    I am thinking we are having language problem.

    My suggestion. Give us an example of what the system supposed to do. And by an example I mean step by step explanation of events. Like: "I press 1 on keypad, the display shows 0001. I press 2 on keypad, the display shows 0010."
     
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  15. ardianlumi

    New Member

    Jan 2, 2015
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    1.Create a digital circuit, which can generate ascii code for the ID.

    For the first combination, the first number of ID will be outputed from the circuit through ascii code and like this till the end of the number.

    This is the text that is in the assignment and its hard for us to, because we dont have full explanation.
     
  16. WBahn

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    Mar 31, 2012
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    So where is the ID coming from?
     
  17. ardianlumi

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    Jan 2, 2015
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    The ID is given [141533535].
     
  18. WBahn

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    Mar 31, 2012
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    What I mean, is that after you have built your circuit and it is inside a black box, how does the circuit know that '1' is the first digit of the ID. Does the person provide this information somehow, or does that information need to be stored within the circuit in the box?

    What is the user interface to this circuit? One button? Two buttons? What?
     
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