FOSDEM 2018 the biggest European even for Open Source technologies is approaching!

Screenshot from 2018-01-23 11-08-37

If you have not been to FOSDEM yet you don’t know what are you missing 🙂

Thousands of people who support Open Source meet together for weekend in Universite Libre de Bruxelles, share ideas and talk on interesting topics for the community.

Here is the list of all dev rooms which will be available. Needless to say for us most interesting is the CAD and Open Hardware dev room.

Looking forward to see you there!

TERES I DIY Open Source Hardware Modular Hacker’s Laptop update


TERES-I DIY laptop first shipments started in September last year and we quickly sold the first initial production run. Immediately we start to get valuable feed back. Meantime the spare parts now are online and can be ordered.


Some of the feed back was quite pleasant like this one sent from Martin Krastev:


Този път ви пиша не с въпроси по подръжката, а като потребител на Терес с
няколкоседмичен опит и впечатления ; )

Знам, че по идея Терес-А64 е бил замислен като хакерски ноутбук, но вече
седмици го ползвам като машина за разработка:
1. Освен проектите, по които работя, Терес сам си компилира и
компилаторите, които ползвам — 2-та ГБ памет наистина правят паралелното
компилиране възможно, та дори да е само -j2 или 3 (нещата, които компилирам са сравнително тежки, и по-голяма паралелност вече опира до суоп файла).
Така че голямо благодаря за ъпгрейда на паметта!
2. Въпреки нищожното охлаждане на чипа, Терес успва да държи по-голяма част от времето 1152МХц, което беше много приятна изненада за мен.
3. Клавиатурата се оказа доста ергономична, въпреки че в началото имах
опасения, че ще е малка.
4. Избора на чип от програмна гледна точка също се оказа удачен – някои
прозиводители на А53-базирани чипове орязват архитектурни фийчъри (демек – инструкции), но allwinner не са от тях (за изненада! ; ) Това ми позволява да не се тервожа, че код писан за по-глеми армове може да не тръгне на Терес.
5. Батерията носи добре на натоварване – дълги компилации не угасват по
средата! : ) А и шината за sd карти държи прилична скорост – напъно
сравнима с вътрешния флаш (при прилична карта, разбира се), така че и
проблемът с допълнително дисково пространство за големи проекти е решен.

Ами това е засега! Исках само да ви кажа, че с Терес сте в правилната
посока, тъй както сте създали напълно ползваем работен ноутбук за арм
програмисти, което си е постижение!


Google translate does satisfactory translation so I would not challenge my English translation skills 🙂


There were two issues we couldn’t catch during our tests and went with the first lot to our very impatient customers:

1. LCD backlight, some LCDs cause the backlight circuit inductor L11 to resonance at annoying audible high pitch harmonic frequency caused by the 300Hz PWM.


According to best Murphy’s law practices this problem didn’t show at the first few laptops we build and tested, but when we shipped the first lot some people complained back about it, so we had to find quick solution.
1.1. adding bigger capacitor 100 uF in parallel to C204 was solving completely the issue, but the boards were already produced and shipped to customers;
1.2. adding double adhesive tape which to press the L11 to the plastic cover solved the issue in most of the cases, if this was not enough sealing the L11 with superglue also stopped the noise, which was caused by L11 vibrations, needless to say this was quick dirty and messy fix

Инфорамция как да ъпгрейднем фърмуер на touchpad и бутони:

This issue was completely fixed with adding 100uF to second production lot

2. Touch panel buttons issue. We run out of GPIOs on the keyboard board so ADC was used to scan these two buttons. Again everything was OK when we tested the few laptops we assembled in house, but soon after the shipment people start complaining that sometimes they press left button but laptop register right button and etc, quite annoying!
2.1. the problem was partially fixed with changing the firmware, we posted new keyboard PCB firmware and instructions on GitHub but this not always solved the problem
2.2. the good fix solution was to decrease the resistor values on the PCB and use 1% precision resistors instead of 5% used initially

We do apologize to all customers who had experienced such problem, we guess they are not many, but if someone has still such issue after the firmware upgrade we will send free PCB3 replacement, just please send us your requests to

In the current KITS this issue is solved.


The initial version of the Linux software was not in best shape, the community helped us a lot and we are now on the third release. Special thanks to Alexey Korepanov for reporting lot of issues and fixes! He also made his own Gentoo distribution for TERES-I at GitHub!


As you all know we suck at mechanical engineering and we had to find all plastic parts from Chinese laptop supplier. Some people asked about possible 3D designs of the laptop case but we are not capable to do this. So one of our customers Jeff Moe who obviously has mechanical engineering skills decided to re-design the plastics and make them as models in 3D printed format – he sends me pictures of his progress from time to time which I post here. So 3D makers be patient – there will be soon 3D printed designs and replacement parts for TERES!

EDIT: Jeff just noted me that the design is made by Brent MacKenzie from the Colorado Printing Project.



IMG_20180118_182208 (1)IMG_20180118_183356

It looks the LCD back plastic he designed is even easier to assembly than the original one.




I will post more in my next post about our progress in turning TERES-I DIY Laptop in portable lab with additonal FPGA board which makes from TERES component tester, Logic Analyzer and Digital Storage Oscilloscope with Sigrok.

A20-SOM204 and SOM204-EVB preliminary info is uploaded on our web


SOM204 is SODIMM form factor System-On-Module we are working for a while (actually from so long time ago that SOM204-EVB platform is made in Eagle which we dropped to use officially from quite some time ago).

The SODIMM connector has these signals:

  • Power supply: +5V, GND, LiPobattery, RTC_backup, Stepup-Output, Stepup-enable, USB+5V
  • Interfaces: Gigabit Ethernet, Megabit Ethernet, CAN, SATA, PCIe, USB2.0 HOST x2, USB-OTG, USB3.0 HOST, HSIC, UARTx3, SPIx2, I2Cx2, CSI, microSD, GPIOs with interrupts,
  • Display: HDMI, VGA
  • Audio: SPDIF, Line-in/out, Microphone, Headphone.

You can see complete SOM204 platform signals here.

The idea behind SOM204 is to make Universal interchangeable SOM with different performance and resources.

Our first SOM204 module is with A20 processor, it’s now in production and will be available for purchase next week.

The second SOM204 module is with A64, the third is with RK3328 which we expect to be ready for production around June. Next to follow is AM335X which will be ready by end of the year together with RK3399. The goal is to have 5 different modules by the end of the year.

A20-SOM204 comes with 1GB RAM, optional SPI Flash or eMMC Flash up to 64GB, two native Ethernets (this is the only A20 board with dual native Ethernets) Gigabit and Megabit, SATA and so on. The USB3.0 interface and PICe interfaces are not wired. On top on SOM204 platform LCD and additional GPIOs are exposed on FPC connectors:



The A20-SOM204 schematic is here.

A20-SOM204-EVB is evaluatuon board with A20-SOM204SOM204-EVB2

A20-SOM204 software is Armbian with mainline kernel and support for all SOM peripherials.


SPECTRE and MELTDOWN attacks and OLinuXino and SOMs


The #spectre and #meltdown attacks were subject to great concerns in the last weeks.

Eben Upton made brilliant explanation of how and why they work in his blog post.

There is already project on Github which can be used to test if your ARM AArch64 processor is vulnerable to such attacks.

As Cortex-A7 and Cortex-A53 are not affected of these attacks this means all our boards with A20, A33, A64 processors are immune.

For A10, A13, AM335X (Cortex-A8), RK3188 (Cortex-A9) we need to do some further investigation.

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.

Espressif got new competitor RDA5981 dedicated for IoT and audio apps


Few years ago Espressif released their first low cost WiFi chip ESP8266 and turned upside down the WiFi connectivity for small MCU. They have been left relatively to no competition from the big Western chip makers who couldn’t match their aggressive pricing, but later there was semi successful competition from Realtek and now there is another competitor who is focused on low cost IoT audio applications but their chip is quite good for general purpose WiFi stuff also. The RDA5981 is based on Cortex-M4 inside

  • running at 160Mhz
  •  160KB SRAM
  • 4MB Flash
  • build in USB 2.0 host interface allow USB devices to be connected to the module directly which is advantage toward Espressif chips
  • Support Bluetooth 2.1 EDR + BLE4.2
  • SDMMC interface
  • 2x 10bit ADCs
  • SIDO x1, I2C x1, I2S x2, PWM x8, IR, SPI x4, UART x2, GPIO with interrupts x14
  • operating temperature -30+80C

According to the PR message their focus is voice recognition / audio play and they shipped already 200 Millions of these chips ин 2016. Looking at the features above they can be used for other IoT applications as well if their SDK is easy enough to use by maker community. The question is will be they smart enough to be more user friendly as ESP.

I check their web and even to download their datasheet they require registration :). I understand this as – we hide our product info from our potential customers as we do not want they to evaluate our chips. These registrations beside pissing off potential customers do not hide anything from their competitors as they would easily register with fake info and get them anyway, but obvious this is the way most Chinese companies work.

via Twitter (Thanks to Rudi!)

EDIT 10-01-2018: There is actually GitHub repo with the datsheet, so their web may be not updated!

Amazon FreeRTOS IoT ported on STM32-E407 board


Amazon announced few weeks ago about their AWS stack support for FreeRTOS. As their development kit is not yet shipping, Roedan Embedded Systems decided to fork their GitHub repo and port to available boards like STM32-E407.

via Twitter

Previous Older Entries Next Newer Entries