2$ DIY Low cost USB Oscilloscope

Were you going to buy a 100-1000$ valued USB oscilloscope? No need of that when you can make one at just 2$.

An Oscilloscope is a device which can analyze realtime voltage or pulse signals and plot their waveform graph in a display. It is also known as CRO, DSO or, an O-scope.

It helps us in analyzing circuit output signals and pulses. Normally it is used in microcontroller projects but it’s also useful in making Any kind of Oscillator for Inverters to check what the output frequency and waveform is.

Image courtesy: usboscilloscope.info


Wondering how is this possible?

Well, this will work with soundcard. Wait, I’m not talking to use your PC’s soundcard, as if I told so, the USB term shouldn’t have been mentioned. I’m asking you to buy a USB Soundcard. Nowadays they are very cheap.
Get at eBay.com from 0.99$
Get at eBay.in from 100 Rs


Why I am asking to buy a USB soundcard and not to use the PC’s internal soundcard?

Because, if you give high voltage or spikes to the input, it may burn and if it’s a USB sound card , it will cost 1-2$, but if you burn PC’s internal Audio system, replacing the motherboard will cost you 40$.


Which software?

Well, there are many soundcard oscilloscope software, but I’d recommend you use Soundcard Oscilloscope or Zelscopeonly, because they provide good functional GUI and Soundcard Oscilloscope has signal generator too so that you can generate signals by the sound out port of USB sound card and analyze signals given to the MIC IN port of the USB soundcard.

Points to remember:

  • USB sound card can handle +-1V i.e, 2V p-p . If you intend to give high voltage, use voltage divider.
  • It can’t analyze DC signals and Ac signals<10Hz
  • Use shielded wire and insulated probes.

Got some question or suggestion ? Just leave a comment, I’ll be happy to talk about it.

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6 Responses

  1. David says:

    When you hit a USB soundcard with too many volts, how does it fail? Is the motherboard truly safe?

    • Arup says:

      The audio controller chip burns in the case. That’s why I recommend using an cheap USB sound card. If you do this directly to motherboard, motherboard’s main audio IC may burn.

  2. Daniel Williamson says:

    The PC motherboard will never truly be safe, but putting a cheap sound card in the way as a sacrificial component during the event of a failure, minimises the risk to the PC motherboard. Id rather spend a few $ knowing it’s likely to take the impact before my expensive motherboard.
    Oh…and just buy a PicoScope 🙂

  3. ben says:

    what is circuit this your project?

  4. Faz says:

    Hi. I think you may have the answer!
    For a live demonstration I would like to plot the wavelength of different lasers (one at a time). I am looking for a very cheap way of doing this thoughts are: laser diode……photosensor -> [your help] -> your idea for USB oscilloscope.
    Are you able (and willing to help me achieve this?
    With thanks

  5. Steve says:

    Too sensationalistic
    100 – 1000 bucks scopes can measure tens of Megahertz freq waveform. Soundcard you can’t barely check the form of a 10kHz wave.. Almost useless

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