to do a mini project in college

Discussion in 'The Projects Forum' started by dark dragon, Dec 11, 2008.

  1. dark dragon

    Thread Starter Member

    Dec 11, 2008
    0 about me:this is my first project and our sir said tat he wont help us so i asking u
    project: "adding and subbracting 2 single digit (base 10) number"
    i have created all blocks upto my knowledge so i need guidelines of practical implemetation....
    i also attacted blocks of operation i created

    plz see the block here:

    explantion of block:
    I/p: i prefer to place keypad for getting input
    buffer: 4 bit Parallel In Parallel Out shift register (2 number with complemented clk)
    (to store addend when clk is active low and augend when clk is high)
    process: it is bcd adder cum subbractor
    O/p : i prefer to use 7 segment disply

    actual problem now i am facing:
    1)i dont know how to use keypad i need circuit of that and how to use it
    2)is there any other way of storing addend and augend (is it necessary)
    3)how to use 7 segment display
    any suggestion of my circuit how to futher simplify it and make it more Relaiable
    any other idea for this process
    Last edited: Dec 11, 2008
  2. kahafeez

    Active Member

    Dec 2, 2008
    hey there dark dragon...... there should be alot more easier ways to do this bt i will do it using a microcontroller....
  3. kahafeez

    Active Member

    Dec 2, 2008
    bt if u r in the 1st year or 2nd year then this might not be a very good approach.... anyways i'll tell u what i know abt a few components

    1. keypad: scanning a keypad through a microcontroller(uC) is very easy. in case u dont want to use it. u can use the dtmf thing. this way each key is identified by the freq it generates... encoder ic are helpful to detect which key is pressed... dont know much abt dtmf bt its simple. not that complex u can try it out. dtmf stands for dual tone multiple freq. google it for more info.

    2. 7 seg. a 7 seg should have 8 pins. 7 for data and one is common. actually a 7 seg is 7 light emit diodes. so one is common. and there are two types of 7 segments. common anode or common cathode. if its a common anode then the common pin should be given Vcc or 5V or something like this. in case the 7 seg is a common cathode type then the common pin should be given ground.... i dont know abt buffers. and processer. may be u should used gates or something. and i think an ALU(arithmetic logic unit) is what u want to design. its easy and u can find it easily on the net as its a very common semester project.