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digital voltmeter by usb using ATmega8

Discussion in 'AVR' started by faraday, Jun 16, 2013.

  1. faraday

    faraday Member

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    HI all
    I wanna to measure an input voltage from -5V to +5V via ATmega8
    how can I use USB connection for that?
    the output goes to PC via USB connector
    and what is the circuit for this project?
     
  2. faraday

    faraday Member

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  3. kubeek

    kubeek Well-Known Member

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    the first thing is that to measure +/-5V you need a +/-5V supply, so you will need some chip to make the negative rail. Then you need to feed your measured voltage into opamp to translate it into the 0-5V range that the micro can measure.
     
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  4. dave

    Dave New Member

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  5. dougy83

    dougy83 Well-Known Member

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    You don't need a dual supply; a simple resistor divider will work.

    You can choose the circuit and base software that suits you best from the demo projects on the page you linked.
     
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  6. faraday

    faraday Member

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    Hi
    thanks for replying, I did it by resistor divider and VUSB :eek:

    2013-06-22-152630.jpg
     
  7. remon7

    remon7 Active Member

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  8. wkrug

    wkrug Active Member

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    For that solution I would take a FT232 Chip. That's a USB to serial bridge.
    PC drivers are availible at the FTDI Homepage ( VCP Driver ).
    At Controller side You can use the Integrated USART. That will make the programming and communication easy.
     

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