13.06.2019 NeoPixel Ring HSV - Neverending story

Previous articles (0, 1, 2) and videos on using the HSV (hue, saturation, value) color model have shown that readers still have difficulty setting the right value to obtain the desired color on the rotating ring. We'll try to resolve this in this article. Using the two buttons and an OLED display we set an appropriate color and its value can be read directly on the display.


22.04.2019 Node-RED: Debug HTTP endpoint

I'm working on continuing the article on Node-RED. In the following article, I will deal with ESP8266 and the DS18B20 temperature sensor. But before we program it all, I'll write this article about HTTP server debugging, which is basically the flow I'm preparing for ESP8266.

16.04.2019 ESP8266 - HTTP server, favicon and error handling

In the previous article, we found that our HTTP server cannot handle hypertext that points to a nonexistent page. We've found that the browser will also request favicon.ico for each page.

12.04.2019 ESP8266 - HTTP server with multiple pages in SPIFFS

In the previous example, we created an HTTP server with three pages. If you look at the source code of the server, you will find the html directory where are the source codes of HTML pages. In this directory I created the design of each page.

11.04.2019 ESP8266 - HTTP server with multiple pages

In this article, we'll build on the articles we learned to create a simple page and give it a nice responsive design. We will now try to create an HTTP server that contains multiple pages. You will be able to switch between pages using hypertext.

07.04.2019 ESP8266 - HTTP server and responsive design

In the previous article, we created an HTTP server with one page. Pages are formatted with HTML tags. Use these tags to design a basic page structure that looks amateurish.

06.04.2019 Node-RED: Arduino and DS18B20

Node-RED can work with serial port. In this article, we will connect the Arduino and the DS18B20 temperature sensor to the serial port. Arduino will send the measurement results through the serial port, and Node-RED will parse them to make it easier to process.


28.03.2019 Node-RED: First flow

This article will show you how to create flows. It will be a simple example based on an example from the official documentation. The generated flow will have one input, one function that modifies the data and one output on the debug console.

26.03.2019 Node-RED: Installation

Node-RED is a flow-based environment that lets you create data flows. It works as a package for Node.js that installs on your computer.

10.03.2019 ESP8266 - HTTP server with one page

In this article we will program the HTTP server using the ESP8266 microcontroller. It will be a simple HTTP server that provides one page. In the example, we'll show you how to program this server.


20.02.2019 Arduino IoT (Internet of Things)

Large companies promise a great future from IoT, and Arduino is not out of the question. In recent months, we've noticed that both Arduino Cloud and Google Cloud have gone from beta to more complete versions. I do not follow Amazon and Microsoft but they also work intensively on IoT.

08.02.2019 ESP8266 - SPIFFS file system

The ESP8266 microcontroller allows you to store data using the SPIFFS file system. The data is stored in internal Flash memory. Flash memory is divided into several blocks.


30.01.2019 ESP8266 - Thermometer with DS18B20

In today's article, I would like to start working on a simple thermometer theme, which I will gradually improve. In the first article we create a simple thermometer with the ESP8266 microcontroller and the DS18B20 integrated circuit. The result will be displayed on the OLED display.

05.01.2019 ATtiny85 - DS18B20 Thermometer

In this article we will describe the project of a miniature thermometer. We will use the ATtiny85 microcontroller and the DS18B20 integrated circuit. The result will be displayed on the TM1637 display.

02.01.2019 Arduino Slovakia in 2019

In 2019, we continue the course. The form of the articles on the blog has settled in the way it suits me. I have set a reasonable compromise between the needs of our children and the pursuit of free time in electronics.


30.12.2018 DS18B20 - Parasitic power mode

The integrated circuit DS18B20 (1-Wire digital thermometer) can be connected in two ways. In normal wiring, pin 3 connects the VCC and the circuit is powered from there. The other option is to connect the pins 1 and 3 to each other and connect both to the GND.

22.12.2018 ATtiny85 - A/D converter

In this article we will discuss A/D converter in microcontroller ATtiny85. We will build on previous articles in which we described the A/D converter in Arduino Uno. In this article, we will show the basic use of the converter and we will identify differences.

05.12.2018 General MIDI 1 Sound set

In a simple way, General MIDI defines a list of sounds. It does not define how those sounds should sound. It only defines a list of sound names.

02.12.2018 Waltz for Esterka

Our little Esterka likes music. That's why I am playing to her improvised simple melodies on the synthesizer occasionally. I'm using a small Korg Volca FM synthesizer.


12.11.2018 A/D converter - TL431 external voltage reference

In the articles on the A/D converter we have already addressed the internal voltage reference. The AREF pin enables us to connect external voltage reference that we can adapt to our measurement requirements. The TL431 is a component that provides us with such a reference voltage.

03.11.2018 A/D converter - an eight bit resolution

The A/D converter in Arduino Uno has a resolution of 10 bits. If you do not need such a large resolution, we can also use a resolution of 8 bits. This will allow us to convert the analog value to a digital value that has exactly 8 bits.


23.10.2018 ATtiny85 and TM1637 display

For several months I am writing series for beginners on ATtiny85 microcontroller. You can use this microcontroller as a miniature Arduino replacement. But miniaturization also brings problems.

21.10.2018 Arduino and TM1637 display

Sometimes we need to display only one number from the Arduino. Then we can fit a small display that displays data using the 7-segment display. The ideal solution is the TM1637 module, which also includes a display driver on the board, which takes care of displaying the data.

11.10.2018 A/D Converter - Free Running Mode

The A/D converter has one interesting option to measure the analog signal as quickly as possible. Starting a new analogue measurement can be triggered by the end of the previous measurement. This mode is called Free Running.

02.10.2018 LED strip as a light for your camcorder

Filming the Arduino using the aluminum frame on the desk requires a lot of light. I used the aluminum half-meter strips that I connected to a laboratory power supply. I attach these strips to the frame during the film to get a uniform light that will replace the daylight.


24.09.2018 A/D converter - Measurement with an interrupt when done

In the previous article, we have programmed an analog measurement that did not block Arduino during the measurement. The end of the measurement was checked using the bit ADSC. The end of analog measurement can also be controlled more conveniently with the interrupt that Arduino calls at the end of the measurement.

24.09.2018 Aluminium frame as a filming aid on the table

Filming small items on the table is more complicated than it seems. Using a tripod, you can only shoot sideways. And a tripod will always hinder somewhere.

21.09.2018 A/D converter - Measurement without blocking

The function analogRead is programmed to block the microcontroller during measurement. During that time you can not do anything else. If you need to make better use of the microcontroller's time to process other tasks, it is advisable to modify the analog measurement so that it does not block the running of the program.

12.09.2018 A/D converter - Internal voltage reference

If you use the Arduino analog-to-digital converter, implicitly it is set so that the reference voltage is AVCC. This default setting allows you to measure with a resolution of approximately 4 mV. You have more options to change this resolution.

10.09.2018 Korg Volca FM - Chinese improvisation

For a long time, I was wondering if the monotonous Chinese music could be played with Arduino. That's why, using my Korg Volca FM synthesizer, I recorded a simple Chinese pentatonical melody, on which I wanted to try the basic methods to create a true copy of the melody using Arduino. Melody consists of two parts.