TUXCON FOSS and OSHW conference 2018 in Plovdiv is just 18 days away, so plan your visit properly ;)


TuxCon 2018 conference about Free Open Source Software and Open Source Hardware will be June 9 and 10th in Plovdiv.

This is community driven event done by volunteers with the support of local IT companies and it’s totally free to participate.

In Saturday 9th of June in the Technical University building there will be two rooms, for lectures and workshops.

Hacking Risc-V core, implemented on iCE40 FPGA and playing with it’s instruction set and making small “monitor” program which allow you to enter programs written on machine code and executed on iCE40HX8K-EVB + iCE40-IO will be demonstrated, so if you want to touch and make your first program on RISC-V “computer” with VGA monitor and keyboard you may find Rangel Ivanov lecture interesting.

Plamen Vaisolov is retro computer maniac and keep working on them, implementing modern floppy disk emulators and other peripherials. He will share his experience with all these who miss Karateka and Load Runner 🙂

Neven Boyanov will talk about his experience with LoRA network and how to start on low budged.

Dimitar Gamishev has two interesting talks, one is for the Open Source Hardware and Software GPS car navigation he made. In the  second he will speak about the home assistants like Google Home and Alexa, how to implement them with small Linux computer like OLinuXino and even with ESP32-Lyra and how to impress your girlfriend by switching on and off appliances and lights with your voice.

There will be KiCAD workshop where everyone (even with no knowledge) will learn how to install, configure and make small robot PCB with KiCAD. Then some general knowledges about PCB materials and how to prepare all files and send to PCB board house for manufacturing. How to select the components, footprints, good routing practices, DRC/ERC checks, Gerber generation and tips how to design your PCBs in way to be produced at lower cost. At the workshop will be our design engineers and you can talk to them directly about issues you encountered when worked with KiCAD or other CAD product.


In Sunday 10th of June we will have traditional Soldering workshop at Olimex training building, where we will assembly and program with Arduino small robot which can follow line or escape from labyrinth. This will be the same robot which PCB we will design in the KiCAD workshop in the previous day. We will go detailed through the program and study how modifications affect it.

The workshop with end with barbeque in Olimex backyard 🙂


We are looking forward to see you in Plovdiv soon!

Arduino Day 2018 in Plovdiv


Arduino Day is on 12th of May and celebrating at near 500 locations all around the world.

TuxCon and Smarty Kids foundation are participating in this initiative and organize event in Plovdiv in Grand center from 15.00 to 17.30.

The event is free and anyone can participate and learn how to program ESP8266-EVB boards with Arduino and to control servo motors remotely.

The original Arduino map is wrong, so if you want to participate please do not go to Saedinenie but to Plovdiv 🙂

The room has limited seats so we advice you to register in advance. If there are more people interested the organizers are ready to do it again for all these who can’t manage to register on time.

MOD-BME280 precise Humidity, Temperature and Pressure sensor Open Source Hardware module with UEXT and Breadboard connector


BME280 is digital humidity, temperature and pressure sensor with I2C and SPI interface.

You can see on this link comparison of different Humidity sensors

The operating conditions are:

  • Temperature -40..+85C;
  • Humidity 0…100 % Rh;
  • Pressure 300…1100 hPa  (+9000m..-500m above sea level);

The sensor works on 3.3V and is with very low power consumption 0,1..3,6 uA.

The easiest way to connect MOD-BME280 is with UEXT connector to any board with UEXT connector as shown on the picture above.

For boards which has no UEXT connector MOD-BME280 can be connected via four jumper wires on breadboard:


The KiCad files are uploaded on GitHub.

The demo software use Adafruit BME280 libraries with two small modifications. The default address in MOD-BME280 is 0x76 while Adafruit library is set to 0x77.

UEXT connector requires D8 to be set LOW to power and 10 ms delay to settle the power before addressing the sensor. The code is at GitHub.

When you run it you will see this:

Screenshot from 2018-03-27 14-35-38

The sensor is very precise, if you move board up and down you can see altitude changes. The 171 meter is the altitude of Olimex building.

MOD-BME280 is perfect for IoT application for environmental conditions logging due to the low power consumption and precise measurements. It can be used both for indoor and outdoor applications.

Is it hot or not? Contactless preciese Infra Red temperature measurement with Open Source Hardware MOD-IR-TEMP


MOD-IR-TEMP is UEXT module which could be easily connected to all our boards with UEXT connector. It has MLX90614 contactless Infra red thermometer which allow you to measure objects temperature from distance.

MLX90614 has internal temperature sensor which can sense temperature in range -40+125C and Infra red camera which can sense external objects temperature in range -70+380C with resolution 0.02C and is calibrated with precision 0.5C in range 0-50C.

There are two ways to connectMOD-IR-TEMP to other boards – first is to use UEXT connector:


MLX90614 works on +3.3V so it’s important if you use Arduino board to make sure it operates at 3.3V or you will damage the sensor.

OLIMEXINO-32U4 has jumper which selects on what voltage it operates 5 or 3.3V you must put the jumper in 3.3V.

The sensor is read via I2C, Adafruit has library included in Arduino library manager.

UEXT onOLIMEXINO-32U4 has power enable and to operate D8 pin should be placed in LOW state.

Here is code:

#include <Wire.h>
#include "Adafruit_MLX90614.h"

Adafruit_MLX90614 modIrTemp = Adafruit_MLX90614();

void setup() {
 pinMode(8,OUTPUT);   //the following two lines enable power supply 3.3V on UEXT connector
 digitalWrite(8,LOW); //you do not need them if you use wire jumpers

void loop() {

Serial.print("Ambient = "); Serial.print(modIrTemp.readAmbientTempC()); 
 Serial.print("*C\tObject = "); Serial.println(modIrTemp.readObjectTempC());

 delay(1000); // can adjust this for faster/slower updates

If you use breadboard you should connect MOD-IR-TEMP GND, 3.3V and SDA to D2, SCL to D3. In this case you do not need to set D8 LOW to operate.

MOD-IR-TEMP allow precise temperature measurement from distance, we are doing some experiments to measure PCB reflow temperature from distance and to measure body temperature.

Our experiments show that how good the temperature is measured depend on object surface. Dark objects temperature is measured better than shiny objects.

If you place your hand in the front of the sensor the temperature is measured correctly from distance 0 to about 5 cm, then the measurement start to register lower temperature. Our guess is that the build in optics has limitation, if you want to measure temperature from greater distance you should add proper optics.


OLIMEXINO-328 special version of Arduino made for low power battery applications

Screenshot from 2018-01-09 12-21-46

Our friends from IrDroid made evaluation of OLIMEXINO-328 board low power modes and blogged about it.

OLIMEXINO-328 is special version of Arduino made for Industrial applications – It can be powered from 9 to 30VDC. The board has build in LiPo charger and step up convertor so when external power is applied or connected to USB the LiPo battery is charged, if both External power and USB connection is missing the power supply is automatically back up by the LiPo battery and OLIMEXINO-328 keep running from battery.

All components of OLIMEXINO-328 work in temperature range -25+85C.

Low power voltage regulators are used to board can be bring down to few micro Ampers when not active.

New product in stock air/water normal closed magnetic valve driven with 12V with quick connect for 6 mm sleeve

Oli DudeN01

We have new product in stock:


WATER-VALVE-6-5MM-12VDC is electro-magnetic valve with normal closed path. It’s driven with 12VDC/0.54A and when power supply is applied opens the valve. It has quick connect for 6 mm sleeves and makes water/air pipes attachment and dis-attachment easy. The valve can work with 0-0.8MPa (0-8 bar, 0-116 psi, 0-7.9 atm) pressure of the air or water.

With this valve and ESP32-EVB you can make IoT watering system, which allow you to switch on and off water supply to your garden or plants via internet.

The demo code is written with Arduino for ESP32-EVB and sources are at Github.

When the server is run you can view the status in your local network:

Screenshot from 2017-12-07 14-59-34

You view the current time and with arrows can adjust time when the watering to start or stop. You can also directly drive your valve with ON and OFF buttons.


TuxCon-Kitty the OSHW TuxCon 2017 conference badge soldering kit is in the web shop


TuxCon 2017 conference was 3-4 of June in Plovdiv. Specially for the conference we made soldering kit badge, designed with KiCad and programmable with Arduino IDE.


Here is how it looks assembled:



The project is hosted at GitHub. It’s good way to learn how to assembly SMT components and how to install, setup and program with Arduino IDE.

Do not hesitate to make pull request for your Arduino sketch if you manage to compose your own music with this board 🙂


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