This article is part of the series of articles called Semblie’s little school of electronics done by our apprentice-intern. This series of articles is intended for beginner electric engineering enthusiasts. We hope this will help you lay some foundations in your electrical engineering endeavors.

This is the first lesson in our series that should introduce you to some basics of electronic hardware development.
Our first project features the ESP32 which will be used to turn on and off a LED.

For this, you’ll need:

  • an ESP32 module
  • resistor, diode
  • 2x connector wires
  • a breadboard

To upload our code to the microcontroller we will use Arduino IDE.

In the Examples tab, select Basics and then Blink. Make sure to select ESP32 module in the menu.

Then add the according to pin and upload the code. Your diode should be blinking now.

Now let’s make our own Printed circuit board.



We will need to add a push button, USB to UART bridge, regulator, USB connector and an RGB diode.


Kicad has a really good 3D viewer which lets you see the components that you are adding.

Here is the file with all the materials used for this project.

PCB layout

We will keep the board small so only the basic rules apply. You should keep the decoupling capacitor close to MCU’s input pin and respect the antenna’s keep out zone. If you have a problem with routing you can always swap GPIO pins to keep the connections short and simple.

Let’s add some mounting holes with a diameter of 3.2 millimetres into each corner and move these push buttons next to the connector.

This is our RGB diode and its 3 resistors.

We have decided to go with an RGB diode instead a simple LED just to keep things a bit more interesting

That’s it, hope that you have learned something today.
If have any questions, please contact us at info@semblie.com, we are more than happy to help you out.

Benjamin Hodžić

Benjamin Hodžić


An electrical engineering student from Bosnia. He’s doing the apprenticeship at Semblie d.o.o. Tuzla.

Semblie is a hardware and software development company based in Europe. We believe that great products emerge from ideas that solve real-world problems.