A simple homemade oscilloscope from a smartphone

A good oscilloscope is too expensive equipment for the average radio amateur, for whom soldering microcircuits and repairing electronics is just a hobby. If you need to monitor electrical signals without obtaining extremely accurate results, it is quite possible to get by with a homemade device. Such an oscilloscope connects to the smartphone screen and operates under the control of a special free application. Its production will be inexpensive and will take only a couple of hours, taking into account the collection of materials.
A simple homemade oscilloscope from a smartphone

Materials:


  • 3.5 mm plug from headphones;
  • wires;
  • heat shrink;
  • Zener diode 2.2V;
  • resistor 2.2K;
  • resistor 1K;
  • test clip;
  • marker body;
  • furniture nail.

Oscilloscope assembly


The figure shows a diagram of a simple oscilloscope - a probe for a smartphone, which needs to be repeated. It is very important to use resistors with the same color coding as in the example, as this will allow you to get maximum sensitivity and accuracy from the device.
A simple homemade oscilloscope from a smartphone

Assembly should begin by preparing the 3.5 mm mini-jack plug from the headphones.The plastic part is cut off from it, after which 2 wires are soldered as shown in the oscilloscope diagram.
A simple homemade oscilloscope from a smartphone

Soldered wires must be additionally secured and insulated. To do this, it will be enough to use 2 layers of heat shrink tube.
A simple homemade oscilloscope from a smartphone

A simple homemade oscilloscope from a smartphone

Next, you need to solder a single-core wire to the head of a small furniture nail.
A simple homemade oscilloscope from a smartphone

A simple homemade oscilloscope from a smartphone

The soldering area on top is insulated with heat shrink. The nail will serve as a positive electrode.
A simple homemade oscilloscope from a smartphone

The wire with the nail is inserted into the marker body with the rod removed. As a result, the electrode must replace the writing tip of the felt-tip pen. You also need to run the wire from the 3.5 mm connector into the punched hole in the back cap of the marker.
A simple homemade oscilloscope from a smartphone

A simple homemade oscilloscope from a smartphone

Next, you need to connect in parallel and solder the zener diode with a 1K resistor. According to the device diagram, a 2.2K resistor is soldered to them.
A simple homemade oscilloscope from a smartphone

A side hole is made in the marker body closer to the writing part. A separate wire is threaded into it, the second end of which comes out of the back of the felt-tip pen.
A simple homemade oscilloscope from a smartphone

A zener diode with a 1K resistor is soldered to the output wire. You also need to connect the power cable from the 3.5 mm jack to them. It is important to maintain the polarity, as in the diagram. The second wire from the mini-jack is soldered to a 2.2K resistor.
A simple homemade oscilloscope from a smartphone

A simple homemade oscilloscope from a smartphone

The wire with the nail must be connected to the remaining end of the 2.2 K resistor. All connections are protected with heat shrink. After this, the resistors and the zener diode must be hidden in the marker body, closing it with the back cap.
A simple homemade oscilloscope from a smartphone

You need to solder a test clip to the wire coming out of the side of the marker, connected to the 1K resistor and the zener diode.
A simple homemade oscilloscope from a smartphone

After this, the hardware of the device is completely ready.
A simple homemade oscilloscope from a smartphone

Next, you need to install the Oscilloscope Pro 2 application on your smartphone. The oscilloscope connects to the phone and can be used for its intended purpose under the control of this program.His test clip is used as a ground and the stud electrode on the marker is a plus. The application in conjunction with a homemade device allows you to set response thresholds, view the signal shape on the display and much more.
A simple homemade oscilloscope from a smartphone

A simple homemade oscilloscope from a smartphone

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Comments (13)
  1. Mikhail S.
    #1 Mikhail S. Guests 18 June 2019 14:02
    16
    Everything would be fine, but low sensitivity and a narrow frequency range negate all the charms.
    Overall, it will be a nice toy, but not suitable for practical use.
  2. Dmitry
    #2 Dmitry Guests 22 June 2019 12:37
    5
    Where are the characteristics of this miracle? Maximum voltage, frequency, etc.? Without this, it is impossible to understand whether such a craft is worth starting.
    1. Guest Anonymous
      #3 Guest Anonymous Guests August 2, 2019 12:20
      3
      If you read carefully, everything is clear - voltage 2.2 V, frequency 22 kHz.
  3. Ivanovich
    #4 Ivanovich Guests 22 June 2019 16:35
    3
    But the program is different!
  4. Andreus
    #5 Andreus Guests 24 June 2019 20:29
    8
    The program in the video is completely different and apparently paid.
    The one indicated in the video, complete G.
    The author is unlucky.
    1. Well
      #6 Well Guests June 25, 2019 07:02
      6
      This one might be.But there are dozens of such programs, and many are free. Not long ago I made such an oscilloscope. Low-frequency, of course, but it’s just right for my needs!
      1. critic
        #7 critic Guests 7 August 2019 11:08
        4
        and what did you want, no matter how sound input
  5. Guest Mikhail
    #8 Guest Mikhail Guests 2 July 2019 12:34
    5
    3 kilo ohm input impedance? Don't tell my hooves...
  6. critic
    #9 critic Guests 7 August 2019 11:13
    9
    Why in the probe diagram is the active end (stud) soldered to the plug to the ground contact, and the passive end to the microphone contact?
    1. 👀👀👀
      #10 👀👀👀 Guests 27 March 2020 13:54
      4
      Well, actually, the active end is soldered to the MICROPHONE contact, and the passive end goes directly to ground.
  7. novel
    #11 novel Guests 29 November 2019 14:12
    6
    and what voltage is it designed for? up to what parameter limits?
  8. Guest Vyacheslav
    #12 Guest Vyacheslav Guests September 17, 2021 11:31
    3
    How can you find out if the phone's jack has a microphone contact? Something like zero effect on 2 copies - except for external noise, no graphs...
  9. Victor
    #13 Victor Guests 7 November 2023 23:31
    1
    It shows something, but I couldn’t get a normal sinusoid. The plug must be from a 4-pin headset