Sitara System On Modules expands with new processor AM3359 and SLC NAND Flash option


We have more Sitara SOMs in stock:

  • AM3352-SOM with AM3352CZBZ100 running at 1Ghz
  • AM3352-SOM-IND with AM3352CZBZA100 running at 1Ghz (-40+85C)
  • AM3352-SOM-512-IND with 512MB SLC NAND Flash on board
  • AM3359-SOM-IND with AM3359CZBZA80 running at 800Mhz(-40+85C)
  • AM3359-SOM-512-IND with 512MB SLC NAND Flash on board

Sitara internal bootloader do not handle well big NAND Flash memories, so for the moment 512MB is what we can use with current design.

SOM204 version with eMMC will be available by the end of this year and it will allow up to 64GB eMMC Flash options.


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.

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

TERES-I Do It Yourself Open Source Laptop update


We are glad to tell you that we finally have TERES-I released!

It was long way but finally we have laptop which works satisfactory to be released.

What we changed since revision B?


Main board now is with 2GB DDR3 ram and 16GB eMMC Flash memory. We add two new connectors CON3 and CON4 to interface the further FPGA module which will turn TERES-I in oscilloscope and Logic Analyzer.

The debug UART multiplexes now with Headphones, so you can plug serial cable to headphone jack and re-direct Debug console UART to Headphone jack. After you finish debugging you can restore Headphones functionality to this jack. We work on USB-Serial cable with headphone jack for the laptop.

We got new 9500mAh battery which now is in TERES kit.

Another improvement is 5V 3A adapter which allow battery to be charged to full in 3 hours. The adapter has charge indicator and comes with convenient 3 meter cable, so you can lay on your bed while your laptop is connected to power supply.

Please give us some days to update all latest Hardware files on Github.

Work-in-progress User manual and Assembly instructions are here.

The software is let’s say about 90% ready state, but works satisfactory even now.

The laptop comes with pre-installed Ubuntu 16.04 LTS with Mate, Firefox browser, Video player, Open Office, Arduino IDE and IceStorm for FPGA development. We will try to include KiCAD later.

Python libraries to access I2C, SPI, UART, GPIOs will be add when ready.

FPGA module with ADC/DACs/IOs will be ready in the next months, it will be easy to insert inside with the other existing boards.

TERES-I is now for sale.

This project took lot of time and we have long list of registered interest for ordering, bigger than the number of laptops we could build in the first run. We guess many of these registered users are duplicated for black and white version and will take just one, but be prepared that after you order your laptop will not be shipped immediately but in 2-3 weeks (or less) depend on workload and number of orders to be processed. Once/if the first run is sold we will make the laptop out of stock and will work on second run which may take few months to complete, but we will produce this laptop until there is interest for it, so if you do not succeed to order during the first run, do not give up 🙂


EDIT: very important notice to add: TERES-I is not designed to scratch everyone’s itch. If you want high performance laptop. If your work involve 8-16-24 core processor power and 4-8-16-32GB RAM memory to do video editing or to compile Linux kernels and Android distributions etc. this is not your laptop! TERES-I software is far for complete and not using 100% performance and features of A64 chip yet, it will work much better and faster in future, now it’s work satisfactory for daily work in motion.

When TERES-I was designed we wanted to make laptop which allow you to travel and do internet browsing, emails check, embedded code development, programming arduino, making PCBs etc. With the further modules it will become more like traveling laboratory to sniff protocols on hardware level, to generate signal patterns etc.


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.

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