+ Post New Thread
Results 1 to 4 of 4
  1. #1
    Junior Member level 1
    Points: 1,018, Level: 7

    Join Date
    Mar 2009
    Posts
    19
    Helped
    1 / 1
    Points
    1,018
    Level
    7

    multiplexing 2 Sim Cards....

    Hello, i want to connect 2 sim cards to a GSM module. And wants to select Sim card through microcontroller.i tried using buffer for selecting sim card, but Main problem comes when it come to selection of I/O pin, b/c as it is a bi-directional pin so i cant use 74ls245 b/c it needs the direction of the data to be told...so what should i do ?



    attached image is of what i want to do, but i cant think up of transcievers that could be used,....
    thanks.

    PS: i dont want to use relay, b/c i made need to add 1 or 2 more sim cards, so us of relays wont be feasible.
    Last edited by tariq7868; 4th April 2011 at 11:50.

    •   AltAdvertisement

        
       

  2. #2
    Full Member level 3
    Points: 4,899, Level: 16
    vinoth8051's Avatar
    Join Date
    Dec 2009
    Location
    Delhi, Kanpur, Madurai, India
    Posts
    179
    Helped
    67 / 67
    Points
    4,899
    Level
    16
    Blog Entries
    3

    Re: multiplexing 2 Sim Cards....

    Hi Tariq7868,
    Kindly check this image, In local indian market we are getting dual simcard adapter, It may help you...
    S. Vinoth Kumar



    •   AltAdvertisement

        
       

  3. #3
    Full Member level 3
    Points: 4,899, Level: 16
    vinoth8051's Avatar
    Join Date
    Dec 2009
    Location
    Delhi, Kanpur, Madurai, India
    Posts
    179
    Helped
    67 / 67
    Points
    4,899
    Level
    16
    Blog Entries
    3

    Re: multiplexing 2 Sim Cards....

    Some more ICs are available (Googled), check this up...
    4557f.pdf
    and Dual Sim Card Adapter
    Hope this helps...
    S. Vinoth Kumar


    1 members found this post helpful.

    •   AltAdvertisement

        
       

  4. #4
    Junior Member level 1
    Points: 1,018, Level: 7

    Join Date
    Mar 2009
    Posts
    19
    Helped
    1 / 1
    Points
    1,018
    Level
    7

    Re: multiplexing 2 Sim Cards....

    thanks alot, using 4557f would solve my problem, but unfortunately, this ic isn't available here & would cost a lot to get it shipped. So i am seeking for a cheaper solution like using one of the 74xx series or somthing like this...



--[[ ]]--