An oscilloscope clock is a unique and creative way to display the time using an oscilloscope, which is a test and measurement instrument typically used to visualize and analyze electronic signals. In one of my previous videos I presented you a way to make the simplest oscilloscope with a small 2 inch CRT tube. This time I will describe to you also a very simple way how to make a Oscilloscope Clock with the same CRT tube. There are several projects of this type on the Internet, but they are relatively complex for self-construction, so I decided to make an Oscilloscope clock in the simplest possible way. It even avoids the use of a mains transformer which is expensive and difficult to obtain, and initially the device works on 12V. But despite its simplicity, it is fully functional, highly adjustable, and has the option of automatically setting the time via the Internet. So it even outperforms more complex devices of this class.

  Basically the device consists of two parts, and one is a signal generator usually made with the help of a microcontroller, and the other part is an X-Y mode oscilloscope that visualizes this signal in the form of an analog clock. 
  First I will focus on the signal generation part. It is extremely simple and uses only an ESP32 Microcontroller board without any external components. 

The code is the work of Mauro Pintus (, and I just made a small modification, so now with a button we can choose between a clock with standard or Roman numerals. If you enter the data of your local Wi-Fi network in the code, the time will be updated automatically via the Internet, and if you do not have the Internet, the initial time that will appear when the clock starts can also be adjusted in the code in the (given) lines:
   int h=10;   //Start Hour 
   int m=8;    //Start Minutes
   int s=37;   //Start Seconds

   This project is sponsored by PCBWay. Visit the PCBWaywebsite and save big, with a time-limited promotion on purple solder mask. From September 1st to September 30th you can get 10 pcs of 2-layer 100x100mm PCBs in purple for only $5. PCBWayhas all the services you need to create your project at the best price.

  Otherwise, I successfully tested a version of the code where the time is set manually through three buttons, but for the sake of simplicity, I left this version out. This time I will not dwell on the installation of the code on ESP32 , as it is described in many detailed tutorials that you can find on the Internet. Regarding the connection method, pin 25 of ESP32 should be connected to X Input, and pin 26 to Y Input of oscilloscope. The ground from the microcontroller is connected to the ground from the scope. Also in one of my older videos you can see how this clock works on a commercial Oscilloscope.

  Next, I will briefly describe the method of making the X-Y mode oscilloscope. As I mentioned before, the device has a complete control of the position and size of the image, which is done with the help of four potentiometers, and there are also potentiometers for adjusting the intensity of the light as well as for focusing the image.

 As in my previous oscilloscope project, I will also use an inexpensive DC-DC step-up for power supply, where with an input voltage of 12V, the output voltage can be continuously adjusted within the range of 45 to 390 volts.

  So the complete device consists of the following components:
   - 2 Inch CRT display type 5LO38I
   - Step Up Power supply module 12V to 300V
   - LM317 voltage regulator with which we get a voltage of 6.3V for heating the tubes
   - Two EF80 tubes as horisontal and vertical deflection amplifiers
   - Six control potentiometers
   - "Mode" button
   - several passive elements, resistors and capacitors,
   - and ESP32 microcontroller board

   At the input...