shift register

Discussion in 'Embedded Systems and Microcontrollers' started by wael_73, Mar 23, 2009.

  1. wael_73

    Thread Starter New Member

    Nov 13, 2008
    please i need to make circuit using microcontroller pic

    this circuit derive voltage to different 32 channels but in serial manner like shift rgesiter .
    i.e the first channel is go high (1) then go low(0) , some delay and the second channel go high then go low and so on until we reach 32 then we start again from channel 1 .

    would you suggest which microcontroller i will use , i think about pic 16f84 but it has 9 port only ,how can i extend this ports ?
  2. RiJoRI

    Well-Known Member

    Aug 15, 2007
    Look into serial to parallel converters. Using 4 converters will give you 32 lines. The converters will share Clock, Data, and Output Enable lines, and have individual Chip Select lines.

  3. wael_73

    Thread Starter New Member

    Nov 13, 2008
    thank you but can i use microcontroller because i need the time (on and off) to be programmed
  4. thatoneguy


    Feb 19, 2009
    You would use the uC for the clock, data, and enable lines, which would allow you to vary which lines are on when, and for how long. How critical is the timing?
  5. Tahmid

    Active Member

    Jul 2, 2008
    Hi Wael_73,
    This is an easy circuit. You can use 2 nos. of 1:16 multiplexers(74150) and a pic micro controller.
    You can very well use pic16f84/16f84A and this Pic does not have 9 ports, rather it has 2 Ports(A and B) and 13 input/outputs. Port A having 5(pin17,18,1,2,3) input/outputs and Port B is having 8 input/output(pin6,7,8,9,10,11,12,13).
    Last edited: Mar 28, 2009
  6. wael_73

    Thread Starter New Member

    Nov 13, 2008
    thank you fo replay i will read (god willing) datasheet of multiplexer ,try it