connection of 8*8 relay matrix to mcu

Discussion in 'Homework Help' started by santu, Dec 23, 2010.

  1. santu

    Thread Starter New Member

    Dec 23, 2010
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    hello , i am in big problem, i am using 89s52 mcu ,please anyone can tell me how could i connect a 8*8 relay matrix to mcu
     
  2. beenthere

    Retired Moderator

    Apr 20, 2004
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    How many I/O pins do you have available? What are the spec's on the relays?
     
  3. santu

    Thread Starter New Member

    Dec 23, 2010
    15
    0
    mcu has 36 i/o pins ,but i have others things also like graphical lcd , can , the mcu chip is at89c51cc03, and also i am using a 5 pin relay
     
  4. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
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    To be more specific - do you have 16 I/O pins to dedicate to the matrix?

    The number of pins on the relay is not significant. The coil voltage and current is very important.
     
  5. santu

    Thread Starter New Member

    Dec 23, 2010
    15
    0
    yes i have 16 i/o pins to dedicate to the matrix,specification of relays are current=12 to 14mA, contact voltage =12 v dc
     
    Last edited: Dec 24, 2010
  6. santu

    Thread Starter New Member

    Dec 23, 2010
    15
    0
    many many thanks for ur support ,alberto. hoping u would help me in future again.thank u
     
    Last edited: Dec 24, 2010
  7. Georacer

    Moderator

    Nov 25, 2009
    5,142
    1,266
    With those voltages involved, special care should be taken, not to bias the diode forward by accident.
     
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