Simple MQTT temperature sensor

Note: this post was first published on Mevisys website.

In the previous post about monitoring temperature we have used a simple RS-485 connection to communicate with a sensor. While this approach is very simple and has been proven to work well in many applications it can be complicated when the amount of connected sensors increases. Also adding or removing sensors can cause complications.

Modern technologies allow us to connect sensors using existing computer networks. For example the incredible ESP32 SoC can easily be programmed to read data from a sensor and relay them over WiFi using MQTT protocol.

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Electronics workshop #2

After the wild success of the first workshop, it was time to make another one. Location and team remained the same: Marius and me had a room in Krikragaa HQ (in Pilies dirbtuves, Klaipeda) at our disposal. This time we have focused more on manufacturing process and simplified the circuit complexity as much as possible. Components: coin battery and flashing RGB LED. Skills taught: PCB preparation. Goal: make a flashing badge.

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Electronic Eglute workshop

A few weeks ago I had the opportunity to organize an electronics workshop in Klaipeda with help of my friend Marius and people from the Krikragaa. The workshop was a part of christmas events – market and workshops.

The goal of the workshop (apart from having fun) was to build a simple flashing circuit with six LEDs. To fit into the christmas mood better, LEDs were usually embedded into custom decorated cardboard christmas tree.

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Eppur is muove!

The final version of the BLDC driver is working, at last. It is a simple modular controller for sensored BLDC motors with easy-to-understand scalar commutation. The code is work in progress, and should be usable in a few days. The hardware was designed so it could be completely assembled manually without special instruments, and the PCB layout is also DIY-enabled.

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N900 USB port replacement

UPDATE 22.1.2018

My old N900 is collecting dust in a drawer for over a year now. However, the time to resurrect this beast might come soon:


About a week ago the USB port on my N900 stopped working. Again. This is another phase of a long battle against that strange force, which keeps breaking it. I have decided to finally give up on micro USB and find a different solution.

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4×4 direct drive RC car

For the first post in new category – electronics, I have decided to share a first glimpse of the project I’m working on for my diploma thesis. It is a model of electric vehicle, more precisely radio-controlled model car, driven by four microprocessor-controlled three-phase brushless (BLDC) electromotors. Rear motors are controlled by custom BLDC drivers based on PIC18 MCUs, front motors by custom driver based on STM32 MCU (my colleague’s work). These three communicate via SPI with the main computer – our beloved Raspberry Pi (currently model B with a mess of wires SPI level converter shield).

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