TERES-I USB debug cable


TERES-USB-DEBUG cable is now in stock. TERES has unique features to multiplex audio port between audio headphone output and serial console debug.

There are two ways to enable the serial debug via audio jack. First one is with teres1-debug on|off script and it will work until reboot:

sudo teres1-debug on

when you want to stop use

sudo teres1-debug off

this is good for try something while your laptop is working, but if you want to catch the early uboot messages you have to use another script:

sudo debug-switch.sh on

this will switch debug serial port permanently to audio jack until you execute the scriupt

sudo debug-switch.sh off

These scripts are included in the official image, but if you build your own you can install them from the GitHub sources

This is FOSDEM 2018


Last weekend in ULB (University Libre of Bruxelles) took place the biggest Open Source event in Europe – FOSDEM.

With 678 talks, split in 55 devrooms this is something every open source enthusiast waits whole year.

It’s amazing how the organizers make such event possible, between 8 and 10 000 people all around the world come together at one place. If you want to meet some open source project, Linux kernel or Linux distribution maintainer there is great chance to meet him/her there.

FOSDEM usually is made in the weekend Saturday and Sunday, but traditionally starts with Friday evening welcome beer party at Delirium cafe. Do not be fooled by the name nobody go there to drink coffee.


Delirium usually can’t hold all people so the streets around it looks like this:


Every year this event become bigger and bigger. I was always wondering how they manage to keep their WiFi infrastructure in order with so many people attending. This year for the very first time the WiFi was impossible to connect to, so I guess we reach the infrastructure capacity 🙂

In Saturday the talks started, needless to say for me most interesting was the CAD and Open Hardware devroom.

One of the most anticipated talk there was about KiCad 5 new features.

Wayne Stambaugh the project manager started his talk with red T-shirt from Digikey and announced that Digikey made the single most significant donation to KiCad team just few days before the conference. So he said them “thank you” by presenting his talk wearing their red T-shirt.


It was very interesting to hear that Wayne got feedback from popular PCB prototype providers, that about half of PCB projects now they receive for prototyping production are made with KiCad! It’s amazing to see the progress KiCad made for the last 4 years!

I personally like more the T-shirt Wayne was wearing when he closed his talk 😉 KiCad team really like the complex boards we design with their product and this was very kind gesture.


Another interesting talk was Introduction to LibrePCB . This is the first time I hear about this project and it looks itneresting. The author is obviously capable young man and thinkered a lot about how to make component libraries more easy to use, but while I was watching the talk I was wondering (as many others) why the author just do not join KiCad, which is already well established project and leading as features and completeness. We all know that KiCad team is very small and more people joining the project will make much more sense than to re-inventing the hot water, because you do not like some feature in this popular project. Well this is the open source 🙂 and everyone is free to scratch his own itch, but I would love to see Urban Bruhin helping KiCad to become better instead to duplicate the work creating similar product alone.

Jesús Arroyo Torrens presented Icestudio – graphical way to program FPGAs. I would say this is quite entertaining and easy start for beginners with no previous knowledge about electronics.


Juan Gonzalez-Gomez (Obijuan) upgraded this talk with very entertaining presentation about what he did with Icestudio and small funny blocks he created. He is using his daughter as beta tester. I recommend you to watch this talk when the video is available.

Juan and Jesus are part of Spanish community working with FPGAs. You can see more about what they do on this site FPGAwars.

Staf Verhaegen shared his findings about is it possible today to implement ASIC design with open source tools. Very interesting topic, let’s hope the time Makers and small companies will be able to make their own chips with Open source tools is approaching.

My talk was about current TERES laptop status and the experience we got during the development with KiCad. Using FOSS tool like KiCad is great to make OSHW, but if you want to use latest features and the daily builds, they are available only via ppa repository for Ubuntu. This means if you use other distribution you have to build from sources every day. Windows daily builds are not available at all. This confuses many beginners who can’t manage to open our files when they want to study them as they use old builds (official Ubintu repository KiCad version is probably one year old, same for Windows version). My slides are now uploaded at Slideshare.

Other devroom talks I found interesting:

Exploiting modern microarchitectures Meltdown, Spectre, and other hardware attacks 

Programming UEFI for dummies 

Improving Linux Laptop Battery Life

Kodi and Embedded Linux

Linux as an SPI Slave

How to keep your embedded Linux up and running

Drive your NAND within Linux

Image capture on embedded linux systems 

New GPIO interface for linux user space 

It was nice to see three four other talks at FOSDEM by Bulgarian speakers!

Automating Your Lights with Open Source 
Turning On the Lights with Home Assistant and MQTT
Testing Red Hat Enterprise Linux the Microsoft way 

Current meta of video compression and probable futures

Overall FOSDEM is must see event for anyone who is interested in FOSS/OSHW.

Bruxelles is excellent location and offers lot to see, both Wizzair and Ryanair offer low cost flights to this destination and I don’t know where else you can drink beer from half meter glass (not half litter but half meter!) so looking forward to see you next year 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 support@olimex.com.

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.

OLinuXino EEPROM content – one step ahead to single Linux image for all A20 boards


We are struggling for some time now to make one single image which to work on all A20 boards we have.

Our problem is that we have more than 20 different A20 boards/revisions/ etc and every time we have to add or improve something we have to generate and test enormous amount of images.

It’s not so easy task as this image should run on different boards with differnt memory speed etc settings, different ports connections etc.

To achieve one single image which to boot to all A20 boards our first step is to add some content in the EEPROM which all OLinuXino has.

The EEPROM now contain this info: Header, ID, Revision, Serial number, Configuration, Reserved area for future (MAC etc), Checkcum.

The new image we work on now (based on Armbian with mainline kernel) will automatically recognize the board from the EEPROM content and run.

What will happen if no valid EEPROM content is read (i.e. old boards), there is tool which to be used to write EEPROM content based on board revision.

We are going to release this image soon.


TERES-I update. First feedback from our customers


Today we shipped all pending orders for TERES-I and we start to get valuable feedback from our customers!

First thing – we missed the magnet assembly in the instruction manual (blush). This leaded to laptops not go in suspend mode when lit is closed.

We updated this in the assembly manual 1.1 which is now on the web and included in the GitHub too in sources so people who notice typos and want to help improveing the Bulgarian-English language in which the manual is written.

Another issue reported immediately which we missed during our testing is that on small percentage of the laptops the LCD backlight step-up inductor cause annoying sound when LCD backlight is with 50% brightness.


It’s a interesting phenomenia as the backlight PWM is 300Hz which is not possible to hear, but when LCD backlight is switch ON and OFF high current surges are happening and some harmonics cause mechanical resonance with this inductor.

The solutions may be few:

  • play with PWM frequency to get away from this frequency which cause the mechanical resonance – pure software approach which need lot of experimenting
  • adding small double adhesive matt on top of the inductor which make contact with the back plastic and this way absorb all vibrations – we start to add this mat as soon as we discover this issue to all laptops no matter if they buzz or not. Not very aestetish but quick and dirty solution:


  • Add more capacitors to the PWM power supply which to handle this current surge, adding 100 uF seems to remove the problem, but the first lot was already assembled and many laptops are already shipped – so this we will implement in the second assembly.


We have two reports about problems caused by the touch pad after “apt-get update / upgrade” we have to look more closely into this issue. For the moment we do not recommend you to update and upgrade your Ubuntu packages or if you do this and something stop working to revert to the original image – this is pretty easy just download the image write it to SD card, boot and run the eMMC copy script.

New Universal System On Module in SO-DIMM 204 pin form factor


We have now several SOMs for A13, A20, AM3352, RK3188.

Each of them with different layout and pinouts as our initial intention was to expose all possible features of every processor.

The experience we got from selling the SOMs for the past 5 years is that 99% of customers do not need all specific interfaces, but few common interfaces.
For instance very few customer need 12 UARTs and 6 I2C in their design, but almost all need Ethernet, HDMI, SATA etc.

Another important point is that soon or later the project they working on scale up and they need more memory or more processor power and with the current SOMs they have no option but redesign.

Every big customer need longevity assurance. They do not want to change their design every couple of years when the SOC manufacturer obsolete their processors, they do not want to re-design every 6 month when new processor with 4-6-8-10-12-24 cores appear to the market with preliminary buggy software support.

So with the years one another idea evolved – we should try to make one universal SOM layout with known interfaces on known pinout, so if customer need more memory he just switch to SOM with same pinout but more memory, if need more power he switch to SOM with same pinout but more powerful SOC.

We have experience with Allwinner, Rockchip and TI, so we considered these processors as potential new SOM SOCs:

A20, A64, RK3399, AM335X

After long discussions we decided that the universal SOM should have these signals:

  • HSIC
  • USB3
  • PCIe
  • Ethernet1 Megabit/Gigabit
  • Ethernet2 Megabit/Gigabit
  • WiFi+BLE
  • SATA
  • CAN
  • IR
  • CSI
  • HDMI
  • VGA
  • Audio In
  • Audio Out
  • UEXT1 -> SPI1, I2C1, UART1
  • UEXT2 -> SPI2, I2C2, UART2


The first SOM204 we made is obviously for A20.

Here are the schematics of A20-SOM204 and SOM204-EVB.

Here is our A20-SOM204 prototype:


Features are: 1GB RAM, 4/8/16/32/64GB eMMC Flash, Gigabit Ethernet interface, 2K EEPROM,
Optional features not assembled by default: SPI Flash with hardware WP, Second Megabit Ethernet.

With this SOM we tested A20 with two Ethernet interfaces: one Gigabit and one Megabit working together. The practice prove A20 can have two separate working Ethernets, but there is one issue both share same clock, so if the both Ethernet works together they can be only Megabit.

The second SOM204 module we work on is with A64.
The features are 2GB RAM, 4/8/16/32/64GB eMMC, Gigabit Ethernet interface, 2K EEPROM
Optional features not assembled by default: SPI Flash with hardware WP, Second Gigabit Ethernet (USB-Gigabit), SATA (USB-SATA), CAN.

The third SOM204 module we work on is with RK3399.
The features are 4GB RAM, 4/8/16/32/64GB eMMC, Gigabit Ethernet, PCIe, USB3, 2K EEPROM
Optional features not assembled by default: SPI Flash with hardware WP, Second Gigabit Ehternet (USB-Gigabit), SATA (USB-SATA), CAN.

A20-SOM204 and SOM204-EVB will be for sale in November. Prices will be comparable to existing A20-SOM A20-SOM-EVB.

A20-SOM204 is separate product and not meant to replacement A20-SOM neigher we have intentions to discontinue A20-SOM. Both products will be active and in production.

Software support for all SOM204 modules will include Android and Linux.

A64-OLinuXino Open Source Hardware board with 64-bit Cortex-A53 processor is in released



A64-OLinuXino OSHW board is now released. Current revision is Rev.C.

Features are:

  • A64 Cortex-A53 64-bit SoC from Allwinner
  • AXP803 PMU with Lipo charger and step-up
  • 1 or 2GB or DDR3L @672 Mhz
  • 0 / 4 or 16GB of industrial grade eMMC
  • SPI Flash in SO8 package with hardware WP (not assembled)
  • HSIC connector (not assembled)
  • Gigabit Ethernet
  • BLE/WiFi module
  • HDMI and MIPI display connectors
  • microSD card
  • Debug console serial connector
  • Audio In and Out
  • LCD display connector
  • GPIO 40 pin connector (not assembled)
  • UEXT connector (not assembled)
  • 5V power jack
  • Dimensions: 90×62.5 mm

For the moment we have three models:

  • 1G0G with 1GB RAM, no Flash, no WiFi/BLE
  • 1G4GW with 1GB RAM, 4GB eMMC and WiFi/BLE
  • 2G16G-IND with 2GB RAM, 16GB eMMC with industrial grade components -40+85C

The optional connectors and SPI Flash etc may be assembled upon request for small fee.

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