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:




25 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

    1. I am having the same problem with my screen how do I apply the command where should I put it thanks for any help …ps I do have the xpt2046 but the touch is not where the buttons are? It’s like upside down and mirrored thanks for any feedbac

  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,

  6. Hi Louis,

    I am interested in getting a set of the pcb’s required for the project. I live in the States (Zip 21032).

    Best regards,

  7. Hi Louis,
    I’ve been having a youtube marathon watching your projects after discovering your channel. Absolutely fantastic content. Do you still have any PCB’s for the DC Load Project and this (DC Voltage Source)? I’m located in the UK.
    Kind Regards,

  8. Hello Mr. Scully,
    I’m trying to contact you regarding The Worcestershire Regiment. Its an amazing source of history and it has helped me very much already.
    I know this is not what your Scullcom website is about but there didn’t seem to be a way or emailing you from The Worcestershire Regiment site.
    I’m wondering if you could assist me in finding people who I could contact, who might be able to help me?
    I’m a 3rd year historical stone carving student at the City & Guilds School of Art, and my main aim for my final year is the creation of a sculpture that is a development on Charles Sargeant Jagger’s work on the Royal Artillery Memorial On Hyde Park Corner. Charles Sargeant Jagger a former soldier of the 2nd Worcestershire Regiment in 1914 who was indeed injured 3 times and received the Military Cross.
    I’m particularly looking for possible patronage that would help me to purchase the stone required but also a suitable place that my finished piece could be placed and perhaps given as a memorial to The Worcestershire Regiment in what is the 100th year since the end of World War 1?
    I would be so very grateful for any help at all, as I’m finding it very difficult to find any contacts.
    Many thanks
    Sue Aperghis

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