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!

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.

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 🙂


iCE40HX8K-EVB OSHW FPGA board is in stock


iCE40HX8K-EVB is upgrade of our iCE40HX1K-EVB with more logic cells FPGA so bigger Verilog projects could be synthesized.

GPIO1 34 pin bus is same as iCE40HX1K-EVB and all DAC, ADC, IO, etc modules are compatible, on top of this there are plenty of additional GPIOs on 4 40 pin 0.05″ step connectors.

512KB fast SRAM is on board, with iCE40-IO board you  can connect VGA monitor and PS2 keyboard, so you can make your own custom CPU (for instance RISC-V) computer with monitor and keyboard.



ESP32-EVB now get much better

ESP32-EVBESP32-EVB revision A was made quick and has too many errors 🙂 some were due to the non very clear documentation, like that we assumed that all ports could have internal pull-ups but  when we try to write the software we found that the GPIOs we used for the buttons has no such. Other were done by our engineer negligence.

We had small 100 pcs series from Revision A, but after all issues we encounter just decided to trash it and just move forward to revision B.

Now in Revision B all interfaces are tested and confirmed to work fine 🙂

What we keep:

  1. Two relays 250VAC/10A
  2. LiPo charger which allow ESP32 to work without external power supply
  3. Reset and User button
  4. micro SD card
  5. UEXT connector to add temperature, humidity, etc sensors
  6. GPIO with all signals available on 0.1″ proto friendly step connector

What we add:

  1. USB connector now is also used for automatic programming of ESP32 so no need for external serial cable, with DTR and RTS bootloader mode is entering automatically
  2. Ethernet now is correctly wired and works 🙂
  3. We were surprised to read ESP32 has CAN and we try and it works great, so in the new revision we add CAN driver
  4. We add Infrared transmitter and receiver, so now you can control all your home appliances with IR control like TVs, VCRs, Air conditioners, and everything else with IR control

What we removed:

  1. second button, with all above peripherals the ESP32-WROOM-32 module resources are gone, there is no single GPIO unused left

Revision B schematic can be reviewed here . The PCB is now routing.

Color TFT 2.8″ LCD 320×240 pixel display board with UEXT compatible to ESP32-EVB is also coming soon.

TERES I Do It Yourself Open Source Hardware and Software Hacker’s friendly laptop is complete


We are proud to announce that our TERES I laptop is complete. We have assembled units and now working on the software.

The building instructions are uploaded here and you can see that it’s pretty easy to build one yourself.

This weekend in Bruxell at FOSDEM we will have table in Hall AW where every one could touch and play with the very first built laptops.

All spare parts are uploaded at the web.

Hardware CAD files and Linux build scripts are on GitHub. TERES I is completely designed with KiCAD FOSS so everyone can download and learn, study, edit, modify.

Hardwarewise everything is OK and works, the software need some care to be completed, power supply management, Linux distribution, and few more details need attention, but we hope everything to be complete till Friday!

FOSDEM 2017 is approaching, are you ready for soldering workshops and playing with TERES-I DIY Hacker’s friendly OSHW laptop?


FOSDEM is the biggest event in Europe about Open Source technologies.

Every year thousands of FOSS/OSHW enthusiasts and professionals meet in Brussels in ULB (Universite Libre de Bruxelles) in 41 Dev Rooms and talk about interesting problems they have faced during the year.

We just got e-mail that Olimex is approved for booth there!

So prepare for soldering workshop fun with the OSHW-GHOST and FOSDEM-85!

TERES-I Do It Yourself Hacker’s friendly modular Laptop designed completely with KiCAD will be also present at the booth.

KiCAD developers are in EDA room and as far I heard there will be very interesting tutorials and how-to’s examples how to implement simple new commands and extensions to KiCAD for people who want to contribute code.

So plan in advance your flight to Brussels, we looking forward to see you there 4th and 5th of February 2017!

Previous Older Entries