GM gear indicator

Discussion in 'The Projects Forum' started by 49willys, Aug 11, 2009.

  1. 49willys

    Thread Starter New Member

    Aug 11, 2009
    3
    0
    First I'd like to say Hi and thanks for any and all help.

    The project I have is for a GM 4L80E transmission I want to keep the stock PRND switch and make a 1 character 14/16 sement display for it. The switch has 4 wires and a ground the arrangement is

    ABCD
    P 1010
    R 1001
    N 0011
    D 0101
    3 1111
    2 1100
    1 0110

    I don't know what I should use micro controller, led decoder/encoder and or combo's and programing to use. Thanks for your time Dave
     
  2. jj_alukkas

    Well-Known Member

    Jan 8, 2009
    751
    5
    If your BCD values correspond to the outputs displayed, you could have used a BCD to 7segment chip like CD4511 to display the data. But It wont. Then you will need to first realize the gating operation logic to the corresponding chip and then feed it to a 14 segment display driver chip(if it is available) or drive it to the display using diodes. However If you know programming, you are better off with a PIC 12f or 16f which would be cheaper and smaller and easier to build.

    You could also check if you could parallel another switch over your current PRND switch and make things simpler.
     
  3. t06afre

    AAC Fanatic!

    May 11, 2009
    5,939
    1,222
    If you are comfortable with using micro controllers so go for that solution. If you do something wrong you just reprogram, instead of rewire.
    Also if you are a micro controller beginner this project will suite you well.
     
  4. 49willys

    Thread Starter New Member

    Aug 11, 2009
    3
    0
    Thanks for your reply's, I don't want to do the diode route I've been looking at micro controllers, encoders/decoders just don't know where to begin,I'll look into the PIC 12f,16f controllers

    Thanks Dave
     
  5. jj_alukkas

    Well-Known Member

    Jan 8, 2009
    751
    5
    You will need 4 input+ 14 output = 18 ports on the microcontroller.

    PIC 12f has only 6 ports, PIC 16F72 would be the best for your application with 22 ports and flash memory.

    It is an excellent project to start for with microcontrollers with just a few lines of codes.

    Any PIC above 16F870 would also do.
     
  6. 49willys

    Thread Starter New Member

    Aug 11, 2009
    3
    0
    Here is a start I chose the pic16F886 and a common anode led. Can I use a 2.5 stereo jack instead of a DB9 I have a cable from another project (automotive) that will help to keep this compact.R 1-4 is 330ohm ?

    Thanks Dave
     
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