DC Voltage Calibrator

Part 1

In this project we will design and build a DC Voltage Calibrator, providing a voltage range from 0 to 10 volts in 1 milli volt steps. The user interface will be a TFT display with touchscreen.
Below are links to version 1 of the software for the Arduino Nano. Also a zip file which contains the schematic, PCB artwork (Version 2) and component layout:


Parts List link below:

Below is a link to my KiCad files for this project:

Part 2

In part 2 of this project we will make a number of improvements and build the unit in to a project case and carry out some tests.
Below are links to download the latest software version plus some zip files with all the project information including schematic, PCB artwork, wiring layouts and parts list plus project case template and front panel artwork:


For the project case simply search on eBay for “7.8”x6.9″x2.7″ Plastic Electronics Instrument Plastic Case Box Shell w/ Handle”
Also available from www.banggood.com as:
7.8 x6.9 x2.7 plastic electronics instrument plastic case box shell

In part 3 we will use new double side PCB’s and improve the accuracy of voltage reference below 2 volts. We will remove the need for calibration of the 1.024V Ref. Also a new battery option will be added. You can download the latest version of Arduino software, schematics and KiCad files from the links below: http://www.scullcom.com/DC_Voltage_Calibrator_Ver6.ino

Parts list can be downloaded from the link below:

Below are links to download the latest Gerber Files for PCB production:




16 thoughts to “DC Voltage Calibrator”

  1. This a great project that I intend to take advatage of. As an enhancement to assist with the calibration of the higher voltage ranges, could a further stage, perhaps utilizing a high voltage op amp (and of course, a suitable power source) be added to take the voltage up to about 100 volts?

      1. Louis, I only discovered your youtube channel in the past week, but was extreemly impressed with the DC load and DC voltage calabrator. I see that you offered boards for the voltage calabrator at one point and was wondering if you still had any available? I haven’t finished the DC load videos yet, so im not sure if you made any boards for that one, but if you did I would be interested in that as well.

  2. Hi Louis,
    I have assembled your DC calibrator as it works very fine, great project.
    But i have tested two similar display, one have a touch chip XPT2046 and works fine, another have a HR2046 chip, and touch don’t work!
    I discovered that the touch works but x and y position are reversed, as the image were upside down.
    I have to change some settings in yours sketch?
    Best regards

  3. Louis, you have done a great job with this project – congratulations…

    Watching the video on voltage setting I thought the use of the touch screen was a bit fiddly in operation. Would it not be better to use a rotary encoder?

    While the touchscreen method does avoid accidental changes to the output setting – which could be possible when using a continuously variable control, it would not be disastrous imo – though it might if calibrating an analogue meter depending on the range setting.

    What do you think about this idea as a possibility?

  4. Or, alternatively, if sticking with the touch screen, use up and down arrows on the screen to increase or lower the output voltage.

    Either of my suggestions would probably require the step resolution to be increased as it takes some time to scroll up or down in 1mV, 2mV or 4mV steps. Who requires anything better than 100mV steps?

  5. Hi Louis,
    Yes, I would be interested in getting a set of the
    pcb’s required for this project.
    I live in the States so, let me know the overall cost + shipping to Calif (Zip 95678).

    Thank You Sir,

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