program to drive 8 * 8 matrix relay

Discussion in 'Programmer's Corner' started by cktcrazy, May 15, 2011.

  1. cktcrazy

    Thread Starter New Member

    Mar 27, 2011

    i am doing the program to drive a single relay out of 64 relays connected in matrix . i ve use 2 port of at89s8252 to connect 64 relays. i ve used to 2 ULN and UDN driver for this purpose.

    i ve connected port p1 to row and port p2 to column of the matrix relay through ULN and UDN driver.

    i tried some logic to drive a single relay . but it did n't work.
    as i making the row pin connected to a relay low and the column pin of that relay to high it is not working as desired . as i set low to row pin all other relay connected to this pin also get activated which is not my desired requirement.

    For example suppose i want to operate 34th number relay i.e . by getting the 3 and 4 command from 4*4 matrix keyboard .

    then i applied some logic to get the 5th row and 2nd column.
    i.e. 34/8 =4 ,reminder 2

    4 +1 =5 got row
    reminder 2 column

    Now i want to operate the relay connected to 5th row and 2nd column.

    well how to achieve this goal of operating this particular relay

    I have attached the circuit diagram .PLZ go through it.

    and help me in this regard. Its very urgent .Waiting for ur response

    regards from cktcrazy
  2. hgmjr


    Jan 28, 2005
    It might help if you provided us with the code you are using to activate the relays.

  3. John P

    AAC Fanatic!

    Oct 14, 2008