Articles 2018



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.


26.08.2018 MIDI in Korg's musical instruments

When you find the MIDI electrical specification on the Internet, you will find only ugly scanned images thirty years old or so. But it does not harm us when we learn from experts. In one Korg service manual, I found a nice circuit diagram of the electrical circuit that they use in their synthesizers.

20.08.2018 Arduino and MIDI out - chords

We continue our experiments with MIDI. In the previous article, we've shown how MIDI out is connected and we've played a few scales. Now is the time to create some music.

14.08.2018 NeoPixel Ring HSV - Return of rotating circles

In the discussion of the video about rotating circles the question was raised whether the red color could not be adjusted to other colors. This article is about finding the right color. Using three potentiometers, you can customize the basic HSV color model and you can also set the rotation speed.

07.08.2018 ATtiny85 - PWM

ATtiny85 has 3 PWM outputs. They are located on pins 0, 1 and 4. In this article we show how PWM is used.

01.08.2018 ESP8266 - Writing text strings with an HTML page

When using ESP8266 as a webserver, you will often encounter examples of strings that are extremely laborious. Any minor change in the HTML code of the site is terribly difficult. C++11 allows us to write text strings more conveniently.


13.07.2018 Cica Mica against ATtiny85

Little Petrík is no longer Bambíno and the click of the switch is no longer fun. Cica Mica came to his place, and she likes clicks on the switch.Will we repeat the success of the first box in which was the ATtiny13A? We do not know.


28.06.2018 Arduino and MIDI out

In this article, we'll show how we can use musical instruments using Arduino. We will use the MIDI protocol, a serial protocol that sends messages to musical instruments. The instruments by the sent message know what note they are about to play.

09.06.2018 Korg Volca FM + PO-12 play Phil Collins

I have a little bit of fun with synthesizers to test their sync and a 16-step sequencer. The Volca FM is a three-voice FM synthesizer, which is a copy of the famous Yamaha DX-7 synthesizer. Dimensions and price predetermine it for domestic experimentation, but it is not a problem to use it professionally.


11.05.2018 Get current weather data using ESP8266

This article will show you how to download online weather data using the ESP8266 microcontroller. We will use to do this.


29.04.2018 Get current weather data using Node.js

In this article, we'll show you how to download online weather data. We will use to do this.

27.04.2018 Edit the robots.txt file for Blogger

Blogger's default setting prohibits indexing of pages that are on the search path /search. If you use labels on a blog, they will be banned by default because they are on the same path. If you want to have them indexed, use this steps.

21.04.2018 NeoPixel Ring HSV rotating circles

The boring theory of the transformation between the color space HSV and RGB is shown in the previous article. In this article we will use the HSV color space again. We'll create rotating animations on NeoPixel Ring using it.

15.04.2018 NeoPixel Ring HSV test

The NeoPixel Ring contains at each point three LEDs that make up a pixel. The resulting color is set using three RGB components. Such coloring is complicated for man, because not everyone can imagine the resulting color, which consists of three components.

10.04.2018 Video stabilization using the program ffmpeg

Each of us who has ever shot a video with a free hand knows the unpleasant feeling that will appear when you watch a recorded video. Without a tripod, the video is almost always shaky. And the shaked video does not affect the viewers well.


27.03.2018 ATtiny85 - Simulation of the fire using NeoPixel Ring

Two years ago, I programmed a fire simulation for Arduino Uno. In this article, we try to do this simulation using the ATtiny85 microcontroller. To prevent the program from being exactly the same, we modify the simulation slightly to set the flashing of the flame.

13.03.2018 ATtiny85 development board on a breadboard

I recently introduced a SMD development board for the ATtiny85 microcontroller on these pages. In today's article I would like to show it in action. This development board has been incorporated into my other boards that I use on breadboard.

09.03.2018 CTC timer in ATtiny84 microcontroller

ATtiny84 contains two timers. One is 8-bit and the other is 16-bit. In this article, we look at timers from CTC mode.

06.03.2018 Rotate the letters received through the serial port

Rotating letters by a specified number of letters is an undemanding task that is also suitable for the beginner. The original idea comes from Caesar's cipher where it rotates by 3 letters. Another modification is the ROT13 algorithm, where it rotates by 13 letters.

05.03.2018 What characters are sent to Arduino via the serial port from Monitor?

For the beginner, it is not easy to understand that, in addition to the visible characters, the invisible characters are also found in the ASCII table. With Serial Port Monitor, we can easily communicate with the Arduino. This program shows what you're sending to the Arduino.


26.02.2018 ATtiny85 - Buttons

Buttons are simple parts that you can use to communicate with the microcontroller. Typically, microswitches are used, which can also be found in conventional consumer electronics. In today's article we will explain the basic use of the buttons and we will program a simple state machine in which we will have to make a button debounce.

24.02.2018 Can Arduino be damaged when is used as an ISP programmer?

This question is asked by people trying to program another microcontroller using the Arduino. If other components are connected to the microcontroller, and the microcontroller has a program that manipulates the pins through which it is programmed, is there a real chance that Arduino will be damaged? To get the answer to this question, let's look at how ISP programming works. The ISP programming algorithm is as follows: A reset signal is set, which the target microcontroller switches to the programming state.

13.02.2018 State machine for Arduino

When you create a project using the Arduino and use buttons and LEDs, you usually create some type of state machine. The state machine responds to the buttons and outputs signals outward via the output pins. You may not even realize that you are creating the state machine that has to adhere to a lot of rules.

09.02.2018 Keep track of uninterrupted Arduino communication using Node.js

If you have Arduino connected to your computer and is sending some data to your computer all the time, the communication may stop. Arduino will jam or the connection through the serial port is disconnected. In this example, we'll show you how to track this communication in Node.

03.02.2018 Simple development board for ATmega328P

The simple development board for the ATmega328P microcontroller and its variants can be easily build on a universal printed circuit board. I've used a version called a stripboard. It is characterized by the fact that it has horizontal copper paths that fit the microcontroller pins.


24.01.2018 DPS3005 cheap programmable laboratory power supply

If you belong to an unpretentious electronics fan and occasionally need an adjustable source of constant voltage or a constant current source, then you can buy this cheap source. It is sold in several modifications and can be bought with a box. The entire power source can be put together from the supplied parts in two hours.

20.01.2018 Andrej Sládkovič, AngularJS and Node.js

In today's article we will continue to work on the poem Marína by Andrey Sládkovič. The aim is to get this poem into the Arduino. Because with Arduino itself, development would take a long time, we will make a small stop at Node.

17.01.2018 Parsing the output from Arduino using Node.js

In this article, we will show how the output from Arduino can be parsed in javascript. Arduino will measure the temperature using the DS18B20 sensor and send the results to the serial port. We will process the contents of the serial port using the code in Node.

07.01.2018 Schmitt trigger as an oscillator

The Schmitt trigger allows you to create an oscillator with a small number of components. We need an integrated circuit 74HC14, a resistor and a capacitor. In this article we explain the principle of oscillator operation and we will visualize the voltage using the Arduino.

03.01.2018 ATtiny85 - Fuses

In the previous article, I forgot to mention it. The ATtiny85 microcontroller is factory-set at 1 MHz. In this article we'll explain how to change this setting and set a higher frequency with fuses.