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Car dynamo output to USB input

Discussion in 'Automotive Electronics' started by dinop, Mar 20, 2017.

  1. dinop

    dinop New Member

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    Hi folks

    I am doing a school project where I need to import a "signal" from the power generator output of a car or motorbike into my laptop through its USB port.
    Does anybody know what would be the simplest/cheapest product to achieve this? I imagine that there would be a way to connect the positive and negative coming from the generator into some little PCB that has a USB port on it which then I would plug my laptop into and read the amps generated through some program installed on my laptop.
    So, essentially, when the driver revs up the engine and the dynamo charges the battery with more amps, I need to be able to see the amps in my laptop add perhaps even be able to show the exact amps flowing through the car generator. Does that make sense or am I talking crap? :mad:

    Thanks,
    Dinop
     
  2. Ian Rogers

    Ian Rogers Super Moderator Most Helpful Member

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    Can you program the laptop using any language? If you can then we go on...

    Can you set up a micro with USB output that will be able to read the current process it and send it to your PC program??

    If you answered yes to both of these then you can go ahead, otherwise you will be looking for "off the shelf" items...

    You can get "ADC reading software" that usually comes with a dongle, you would need one with current sense.

    Also look into IOT as I have bought a little WEB PCB.. Cost about 29 quid... It connects to the internet via ethernet... It has its own web page that you just log onto.. https://www.olimex.com/Products/PIC/Development/PIC-WEB/
     
  3. dinop

    dinop New Member

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    Hi Ian and thanks for your reply.
    Yes, this is a "greenfield" project so I have no restrictions, whatsoever.
    I am essentially trying to build or buy the cheapest device possible that would convert the revs of a running engine into a USB signal. I saw the PCB you linked to but it has an RS-232 connector, not a USB...
    My laptop does not even have an RS-232 so I would have to buy an additional RS-232 to USB adapter or something like that.
    Imagine that when the driver steps on the gas and perhaps the alternator generates more power to provide more amps to the battery, my device will send a bigger integer through to the USB.
     
  4. dave

    Dave New Member

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  5. Ian Rogers

    Ian Rogers Super Moderator Most Helpful Member

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    It has Ethernet... So has your laptop...
    Yep.. I know how it works.... If you need special stuff then sometimes the only way is to make your own.. It's relatively easy to do...
     
  6. dinop

    dinop New Member

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    So, do you think the way I am approaching the problem is correct? Assuming we have no access to the vehicles "engine computer" is the alternator amperage the best way to see how high the engine is revving?
     
  7. Ian Rogers

    Ian Rogers Super Moderator Most Helpful Member

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    Nope... The alternator current is only dependant on the depletion of the battery... Once it's charged the current output is much reduced... If you need revs, you need to tap into the AC before the diodes.. You might be better off with an ODBII device... Only £8 and display everything.... How old would the vehicle be...
     
  8. dinop

    dinop New Member

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    We are talking about modern vehicles. i.e. post 2005, I guess. ODB2 was the keyword I was looking for! :cool:
    I guess this is a connector that plugs into the car's diagnostics port and transmits various stuff, right?
    This would be the correct way to get the vehicle's speed or power output. Yeah? :woot:
    Magic! There seems be one with WiFi built-in for a very small cost! :)
     

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