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Anyone here in MD? Looking for local prop coding/hardware h$$$lp ... — Parallax Forums

Anyone here in MD? Looking for local prop coding/hardware h$$$lp ...

turbosupraturbosupra Posts: 1,088
edited 2009-12-31 05:23 in Propeller 1
I ask for local, because some of the data acquisition/testing really needs to be done on my car locally.

A lot of people have been really helpful on this forum (especially Stefan), but I have a project that really needs to get off of the ground ASAP, after 3.5 months (start to present) and the 6 months that I estimate it will take me to learn what others already know, to complete a relatively simple project is just too long [noparse]:([/noparse] .

I don't want to come across as taking the easy way out, but what will take me 6 months and a spring semester of 1 or 2 prerequisite EE classes, could probably be done by someone with a decent amount of experience, in an evening or two, so I'm willing to pay for someones time and the ability to ask a few questions along the way so that I can learn as well.


In short, I need a circuit/code that can read my vehicles tachometer signal, or crank signal, send out a 14v pwm signal based on rpm, read when an inputB is < 1.65v and > 1.65v and output 3 different voltages depending on the state of the rpm pin input and inputB.


If interest in making a few extra bucks, please let me know, thanks for reading.

Comments

  • ElectricAyeElectricAye Posts: 4,561
    edited 2009-12-31 05:23
    I'm in Maryland but I'm sorry to say I am both totally swamped with work and also very inexperienced. However, I do know that this forum can be quite helpful if you can break up your project into distinct parts, ask specific questions, and have time to try a few things yourself. Of course, if you're really crunched for time and just want to hire someone to do it all then my feeble bit of advice is worthless, but here's something to think about to maybe help you get started.

    Maybe "Divide and Conquer" would be a reasonable way to begin:

    Consider using the IRF3708 MOSFET with the Propeller and the PWM Object.
    The Propeller's built-in counter modules can count pulses from your tach and command the PWM Object to output whatever PWM you desire based on rpm.
    Perhaps you could use a comparator circuit or two to monitor whatever inputB is. The outputs of the comparators would feed into the Propeller and tell it when inputB has exceeded the comparators' thresholds.
    Where I'm totally clueless: how to output 3 different voltages depending on the state of the rpm pin input and inputB. Perhaps the Propeller can have 3 dedicated output pins, each of which will drive a MOSFET that can output whatever voltage is required. You'll have to ask the forum for better advice on this.

    Generally speaking, I would say your project doesn't sound very difficult. It's just a matter of cobbling together existing Objects and writing the code that brings it all together. I really don't know anything about the electrical systems of cars, but I'm sure there are people on the forum who know all about it.

    To get some idea of how to work with the MOSFET and the PWM Object, check out this:

    http://forums.parallax.com/showthread.php?p=844589

    Anyway, that might be something to think about until people get back from the Holidays and can really help you out.
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