Need help with digital tachometer

Discussion in 'The Projects Forum' started by artofkicking, Jun 5, 2011.

  1. artofkicking

    Thread Starter New Member

    Jun 5, 2011
    Hi everyone. I am new here and trying to build a display for my motorcycle (vs1400).
    What I have in mind is a display for the engine speed in rpm's along with with other displays for voltage and temperature.

    My problem is with the tachometer.
    I figure on using a timing circuit based on the 555 chip like this:
    and a four digit display like the one at this site:
    my question is, What do I need to do to get the display show me what I want?

    I have been doing some research on the web when time permits but so far I have found no definitive answer to my question.
    Any help is greatly appreciated. If you have only a small part of the puzzle please post. You may have the piece of information that solves this design problem.

    Once I have a working unit, I intend to do a complete write up for anyone else who wishes to do something similar.
    Last edited: Jun 5, 2011
  2. someonesdad

    Senior Member

    Jul 7, 2009
    If you're going to use that display, note that it has an I2C interface (serial). The logical thing to connect to it is a microcontroller, which would also be good for measuring various voltages, doing the timing for the tach, etc. But this isn't really a beginner's project, as it will take some serious study to learn how to write the software. However, if you're interested in pursuing it, there are lots of people available for advice.

    I understand the desire to build it yourself, but you might want to first look around and find out what's offered commercially. If you value your time at a very low rate, say $10/hour, realize that the commercial device will cost you a lot less than designing and building one yourself. Of course, the latter approach gives you satisfaction and experience, so it might well be worth your time. You decide.
  3. artofkicking

    Thread Starter New Member

    Jun 5, 2011
    Thanks for the reply. You are correct, I just noticed the "analog" meter in the circuit.
    As far as the money goes, it is more about doing it myself than the money. I could say "look what I bought" or "Look what I made"
    I prefer the satisfaction of the later.:)

    P.s. I am looking at some basic stamp micro controllers, but as you said this is not a beginner project and there will be much research before the development of the unit.
    I already have the temperature sensor and the voltage output figured out. The total unit will also include high beam indicator, neutral as well as left/right signal indicator led's.

    It will be something special when it is completed
    Last edited: Jun 5, 2011