identifiying pre programmed mcu communication

Discussion in 'Embedded Systems and Microcontrollers' started by sss r1, Aug 7, 2008.

  1. sss r1

    Thread Starter New Member

    Aug 7, 2008
    first of all , i want to say hello :) i'm new here and this is my first post.
    i'm a newb to mcu's so plz be patient guys.

    the problem:
    i've bought a gauge cluster unit for my motorcycle from a different model .
    most of the time those gauges work alike , the speed sensor sends square wave signal which is translated by the gauges mcu to the 7 seg speed display.
    the rpm sensor works the same way ... and the temp sensor also...
    now with this new gauge i got , things are a bit complicated. it gets all the data via serial communication of some kind from the main engine control unit.
    now i need to convert my sensors data to serial data , so it can be received by the gauge.
    the problem is , i dont know what type of data is send , how many bits at a time... things like that.
    the mcu inside is nec 78063 (a) , heres the datasheet i found
    its a 8bit mcu .
    any help would be great .
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    Your information is a bit confusing. Let me see if I can restate it.

    The old gauge cluster was set up so each instrument took the analog input as a direct input and converted it to digital on the spot.

    The new cluster can only display digital data sent from a central microprocessor as a serial data stream to each gauge.

    If that is correct, then the new cluster should be able to function if you can route the inputs to it properly. Do you have any documentation that describes the connections to the new cluster?

    Without the wiring diagram/schematic for the new instrument cluster, it's just not possible to say what you need to do to make it work.
  3. sss r1

    Thread Starter New Member

    Aug 7, 2008
    thanks for trying to help!
    the old cluster had inputs from all the sensors individually.some of them were analog inputs , and some were digital .
    for example , the input for the speed was a simple square wave signal. with increased freq the claster showed higher speed.
    the imput of engine temp was from a simple thermstor etc...

    now , the new cluster gets only one digital signal which supposed to transmit all the sensor data from the ecu.

    old system = all the sensors connected directly to the gauge.
    new system =all the sensors connected to the ecu and then transmited via digital serial communication to the gauge.
    so the signal the new gauge is getting is not a simple square wave . its a digital signal that holds data for few sensors.
    i hope i explained it better this time .