A20-OLinuXino-LIME2 review and updates


Sorry for blogging so late for A20-OLinuXino-LIME2 but last two month every week I had to travel somewhere.

This is also the reason for the two last weeks without Weekend Programming Challenge and Friday Free Board Quiz.

I promise these will be resumed next week after Open Fest :)

A20-OLinuXino-LIME2 is product of the continual improvement of our OSHW OLinuXino boards based on your feedback, tips and suggestions.

The major differences to A20-OLinuXino-LIME are:

1. Much better routing of DDR3 memory. We increased the number of layers to 8 vs the 6 layers in LIME, we put the DDR3 memory closer to the A20, we layout the tracks shorter, as result now LIME2 runs with DDR3 on 532Mhz on LIME there were problems to run DDR3 at more than 400Mhz.

2. Double the memory, LIME2 now is with 1GB RAM and we expect 8Gbit DDR3 memories to experiment on having LIME2+ with 2GB RAM (shhhhht do not tell anyone and do not ask when it will be available as we also don’t know if these experiments will be successful).

3. Faster Ethernet, now we use A20 GMAC instead of EMAC so LIME2 have Gigabit Ethernet.

4. GPIOs 0.05″ connectors now made right. When we designed LIME we first though to use female connectors instead of male, but when we finished the design we realized that this time we will break the order we made all “mother boards” to have male connectors (to may connect to ribbon cables) and the shields/modules/capes to have female connectors. In the last moment we decided to make LIME with male connectors and we had the dilemma – to go again to re-routing and prototyping or just to assembly the female connectors with male, we wanted to release LIME earlier so we went with the latter without realizing that this way when cable is attached the cable numbering will be mirrored!

Once we made this mistake we continued it with A10-OLinuXino-LIME-UEXT as otherwise we couldn’t have functional extension board.

Then we had internal discussion if we have to make these GPIOs right, the problem was that there were already many thousands LIMEs sold so what to tell to our customers who already bought LIME and made shields for it? So we left it “as is”.

In LIME2 we decided to make it right and LIME2 is with connectors which have no mirror, but this make them incompatible with LIME :(  What we will do now is to make new version of LIME with correct GPIOs, but we will keep the production of the old LIME too, just have to figure out how to name the new board to not add more confusion to our customers.

So to conclude about the GPIOs:

LIME and LIME2 connectors are with different layouts (mirror). This means you can’t use A10-OLinuXino-LIME-UEXT on A20-OLinuXino-LIME2. We have A20-OLinuXino-LIME2-UEXT which is in production and will be ready around 10th of November in Stock.

Also new version of our A13-LCD4.3 A13-LCD7 and A13-LCD10 is developing which have standard 40 pin LCD connector to attach to A13-OLinuXino and A20-OLinuXino-MICRO + two small connectors for direct connection to LIME and to LIME2. I hope this is not confusing for you too :)))

Here is picture on the new LCDs:


as you can see you can connect directly now any of our boards including LIME and LIME2 without need to go through adapter board.

I’m sorry for all these confusions but we decided to make thing right and move forward than to keep the GPIO error forever (Arduino for this reason keeps the shield connectors off 0.1″ step, they made initial mistake but decided to not correct it).

Now we will have the inconvenience to keep LIME (mirrored GPIOs), LIME2 (correct GPIOs) and NEW-LIME(correct GPIOs) but this is our mistake and we want to fix it.

EDIT: Something important! Debian and Android images for LIME and LIME2 are different because of the memory and Gigabit ethernet, so if you have LIME download the images for LIME if you have LIME2 download the images for LIME2!!!

Open Fest 2014 is approaching, get ready for the Hardware Hackathon!


This weekend is Open Fest 2014 in Sofia! We will be there with table and Hardware Hackathon. This time we will have two new boards to assembly but we will keep this as secret :)

Also Olimex will have lecture “Programmable Home” presenting the new boards and solutions we work on for Home Automation.

Here are some pictures of the Hardware Hackathon we did on Open Fest in 2013.


This time we will have more and different boards to choose from, and of course the Hackathon will be free (as beer, not speech ;) ), so you can take the board you assembly with you after the Hackathon.

Looking forward to see you there!

Radxa Rock Pro/Lite Is OSHW Now!


Tom Cubie is an ex Allwinner software developer who helped a lot in the beginning Linux-Sunxi community with information about Allwinner chips, when the initial Linux support was done.

He together with another Allwinner employee made Cubie Tech startup and start developing low cost Cubie boards with Allwinner chips.

At one point of time Tom become interested in Allwinner direct competitor – Rockchip, but it was problem to implement inside Cubie Tech board with Rockchip as this would cut all connections between Cubie Tech and Allwinner, so he decided to split and made new startup Radxa dealing only with Rockchip boards.

I know that Tom as being Linux developer loves in his heart Open Source, but at the same time he was very afraid to take the final step and move his projects as OSHW as in China everyone copy everything.

It’s common practice when you have successful product other companies to make inferior quality clones, made with lower quality and lower grade components but at lower than your price, and because many people look at China just as low cost source they prefer to buy the lower cost clones than the originals although most of these clones are pure junk, (but hey I got Allwinner board for $12.34 and Arduino clone for $1.23 on Alibaba!). This makes the business in China very difficult and everyone hides his designs and knowledge to have advantage toward the copycat competition.

This is also big obstracle for the OSHW movement in China, if you check on Kickstarter/Indiegogo all projects which come from China and claim to be Open Source Hardware are just marketing and pseudo OSHW they publish just the schematics as PDF file and eventually software sources, and “promise” to release everything when they complete the project … which usually never happens.

Let’s take as example the populart Vocore project which inspired RT5350F-OLinuXino ;) they claim on Indiegogo this is OSHW project : https://www.indiegogo.com/projects/vocore-a-coin-sized-linux-computer-with-wifi

They got funded, produced the boards and shipped them, on their site vocore.io you can read:

You will not only get the VoCore but also its full hardware design including sch, pcb, bom; full source code including boot loader, os(openwrt), applications. You are able to control EVERY BIT of your VoCore

then on download page you have access just to PDF files.

I write all this above just to show you what big step Tom decided to move forward yesterday! He wrote on G+ :


Here is the G+ original post.

Obviously Tom follow my blog posts and after my post yesterday for the differences between Pi and OLinuXino and what benefits OSHW gives to the Business he finally decided to go OSHW for his new Radxa Rock Pro/Lite design (at least looking at the commit timestamp). This is something I just could just applaude! Good work Tom and Welcome to OSHW movement!

Keep the good job going! Sharing the knowledge just increase our power!

RT5350F-OLinuXino Update



We startd our OLinuXino with RT5350F back in July right before our Summer vacation.

As soon as I blogged about it we got tons of useful tips and advices on the blog and by e-mails, like info about RT5350F frequency tunning, Antenna design, Overheating internals, which was not obvious from the skinny info on the web.

We decided to build two prototypes one with integrated and one with discrete baluns and on the picture above you can see the version with balun on left and discrete components on right side. Here is how the boards look on back side:


Our first intention was to make this board with 64MB of RAM and 8MB of Flash, but after reading more carefully the datasheet we found that this will require two RAM memory banks and two chips, which would increase the size of the board, so we decided to keep the size and make only 32MB RAM, but to increase the Serial Flash to 16MB.

The prototypes start working from the very first time, which makes me to worry about what we did wrong :)

The schematics and CAD files are on GitHub. Note these are preliminary and we have to update them with the latest components exchanges like SPI memory now is W25Q128FVSSIG and RAM is W9825G6JH-6.

Although we got tip for the tendency RT5350F to overheat (it uses internal LDO for 1.2V which dissipates enormous amount of heat and can cause the chip to desolder from the high temperature, we are non-believers and wanted to try ourself… well the result is that RT5350F really overheats :) as this 1.2V could be feed from outside too, this will be solved in the next revision and we will put small external DCDC to release RT5350F from this heat source inside the chip.

This is our test setup we made small carrier board with 5 Ethernet ports and USB host to may test the board functionality, do you see the big heatsink :) :


the cable on the left side is JTAG for initial uboot programming to the SPI Flash, the small board on the right side is the USB-Serial for the console.

The OpenWRT is running fine, so after all tests are done next week we will experiment to lower the heating and make new prototypes.

What we still didn’t decided yet is what EVB to make for this board?

Initial though is:

  • x1 or 2 Ethernet ports
  • x1 USB host
  • x2 RELAYs
  • few GPIOs with optical isolation
  • UEXT with UART/SPI/I2C for connecting UEXT modules
  • small 4 digits 7-segment display
  • all this put in nice compact DIN enclosure

it will be easy to put on DIN rail and to measure things and connect to Internet:


Definitely with these problems of the overheating the board will have no problem to run on negative temperatures, just the problem will be if the ambient temperature rise above 40-50C :) but let’s see what will happen with external DCDC in the next revision.

As always we are open to hear your suggestions :)

OLinuXino now can be produced in Industrial grade -45+85C

hynix micron
When we made OLinuXino design our intention was to make it working even in Industrial temperature ranges -45+85C.

Unfortunately we struggled to big problem, we couldn’t find DDR or DDR3 memory in Industrial temperature.

Most of the DDR memories are used for consumer products – phones, tablets, computers with 0-70C operating temperature.

At Electronica 2012 exhibition I went through all memory producers and only Micron confirmed they have industrial grade memory, then when I wanted to place order the European distributors asked me something like EUR 20 per chip and minimum order of 5K pcs which was insane if you want to build low cost product.

The situation with SD cards is similar, to find 4GB SLC Sd-card Class10 in industrial temperature and certification the prices were starting at EUR 30 for 1000 pcs, also not good option.

So for a while we put this industrial grade idea aside, but I was keep looking for industrial DDR memory sources.

Now I’m happy to tell you that we finally found DDR memories in industrial grade for both imx233 and Allwinner chips, so we now can manufacture these boards in industrial grade temperature:

  • iMX233-OLinuXino-NANO
  • iMX233-OLinuXino-MICRO
  • iMX233-OLinuXino-MAXI (we have both LAN9512-iJZX and DDR in industrial grade)
  • A13-OLinuXino-MICRO

as GL850 USB hub can’t be sourced in industrial grade these boards can’t be made industrial:
iMX233-OLinuXino-MINI, iMX233-OLinuXino-MINI-WIFI, A13-OLinuXino

We are now searching industrial grade Ethernet PHYs to may offer also these boards in industrial grade:

  • A10-OLinuXino-LIME
  • A20-OLinuXino-LIME
  • A20-OLinuXino-LIME2
  • A20-OLinuXino-MICRO

note that the price of the industrial versions will be a bit different due to the higher price of the industrial grade memories and Ethernet PHYs

for iMX233-OLinuXino-NANO and MICRO this is +EUR4.00 for iMX233-OLinuXino-MAXI and A13-OLinuXino-MICRO this is +EUR 5.00

also note that the industrial grade boards may be subject to MOQ of 50-100 pcs and will not be shipped from stock as standard products but you may need to wait 1-2 weeks to be assembled, tested and packed.

OLinuXino and Raspberry Pi compare


While we have been on Linux Con lot of people came to our table where we had our OLinuXino boards.

One of the most asked question was: What is the difference between OLinuXino and Raspberry Pi?

This is self understandable as Raspberry Pi is the most popular small Linux board and it’s natural people to have heard of it – RPi Foundation with the Broadcom support made sure it’s all over the news, while OLinuXino is still small project.

As we hear this question again and again I though it would be good idea to blog about it so people can read and instead to tell them one and same thing again and again to just refer them to this blog post.

Raspberry Pi Foundation goal is to teach kids programming for this purpose they have created small and low cost Linux board, which helps them to reach their goal. Many people use this small computer for other purposes as well, this is not the best design in the world, nor fastest and the richest in features, but it’s just good enough for RPi foundation to achieve their targets and this is why they do not develop/improve it more since their start.

What they have is one board which they were selling half populated as Model A and completely populated as Model B, then recently they made some small improvements and named the model B+ to name the changes they add some more GPIOs and replaced the linear power supply with DCDC to make it more power efficient, sure they have also module which though is with almost same price like the Model B but having less functionality as complete product, so I guess its not so popular as less usable for most of RPi community.

When we designed our first OLinuXino based on imx233 we wanted to make Linux board which everyone could make even alone at home (the project was inspired by Raspberry Pi, but looking from aside all the troubles they had with deliveries and manufacturing at the beginning we wanted to give option to people to MAKE their own LINUX computer at home).
OLinuXino is Open Source Hardware project so soon after we made our first boards we got lot of feedback, tips and suggestions from our small but efficient community which was formed around OLinuXino, so we continued to experiment and went to less DIY chipsets as our collaborators wanted to see more and more power, so we switch to A13 SoC which is the first TQFP Cortex-A8 processor, then to A10s, A20 Dual Core chips and this process don’t stop even at the moment.
For the last 2 years we made more than 20 different OLinuXino boards with prices from EUR 18 to EUR 65 and with processors from ARM9 to Dual Core Cortex-A7.
Now We have Rockchip RK3188 prepared for production with Quad Core Cortex-A9, in the design pipeline is our first big.LITTLE octa core Cortex-A15/A7 A80 design and probably next year we will have Cortex-A57 64 bit ARM OSHW board.

So let’s start with the major difference:

OLinuXino project is completely Open Source Hardware project, this means everyone can look at our CAD files, see how we have done them, learn, study and modify them for his own need, and even later to manufacture and sell products based on it. For these two years there are hundreds of derivative designs made by individuals and companies, thousands of people learned that to create Linux computer running at 1Ghz is not so difficult!

OSHW business model is more attractive not only for hobby users, who benefit from the knowledge sharing, but also for companies as it gives them INDEPENDANCY. They are FREE to buy from the creator Olimex, or to make the project themself, or if they can’t manufacture to HIRE someone else to make it for them! This secure their business. Even if Olimex decide to stop producing OLinuXino (hypothetically) at one moment of time, this will not hurt them as they have ALTERNATIVES.
If I have company which want to make commercial product I would go with project where everything is UNDER MY CONTROL and this is what OSHW gives to the business.

To get back to the comparison, A10-OLinuXino-LIME selling for EUR 30 is close to Raspberry PI $35 selling price so let’s see what are the similarities and differences:


  • both boards run Linux
  • have SD-card for boot
  • both boards have native HDMI with Full HD for connection to TVs
  • two USB hosts, Ethernet
  • about same size


  • Cortex-A8 1Ghz ARMv7 processor vs. ARM11 ARMv6 obsolete technology makes A10-OLinuXino-LIME to run up to x4 times faster than Raspberry Pi
  • OLinuXino can run standard Debian, Ubuntu, Fedora, Arch etc as use ARMv7 and is officially supported and have access to the standard repositories and packages for these distributions
  • USB hosts can source up to 1A current for the USB devices connected, allowing such devices like USB-3G modems to be connected
  • OLinuxino have USB-OTG
  • OLinuXino have Native 100Mb Ethernet interface not USB to Ethernet converter like RPi
  • OLinuXino have Native SATA and SATA power supply which allow Hard disks to be attached directly!
  • OLinuXino have 2 MIPI parallel camera interfaces
  • OLinuXino uses power efficient DCDC converters, while RPi uses linear regulators (fixed in Model B+)
  • OLinuXino have 160 GPIOs available for the user while RPi have 17
  • OLinuXino can drive directly LCDs with parallel and LVDS and touchscreen, while RPi count only on HDMI displays
  • OLinuXino have build in Lithium Polymer battery charger and step up converter, so when you attach LiPo battery to OLInuXino it will charge it, and if external power supply is removed the battery power will be used to generate all power voltages includein these for the USB host and SATA, i.e. you can run OLinuXino for hours on single 3.7V LiPo battery.
  • OLinuXino can run Android 4.x while PRi have no power to do this
  • OLinuXino community is smaller
  • OLinuXino LIME can have DUAL-CORE Cortex-A7 A20 SOC which not only increases the speed with 40% but also decreases the power consumption by 30% vs. A10 Cortex-A8 processor
  • OLinuXino LIME2 have 1GB RAM memory and Gigabit Ethernet interface.

So overall OLinuXino offers more security for the business, more different products with different features which to match different use cases.

Olimex is OSHWA member now


I already blogged for my visit in Rome for the OSHW Summit 2014.

While chatting there with Drew Fustini he asked me if Olimex is OSHWA member and I reallized that while being busy with developing OSHW projects Olimex actually forgot to become an formal OSHWA member, so when I returned back I quickly rectified this and applied for Supporting Corporate Membership.

Few weeks later I got this in my post box these nice stickers!


Now I just have to figure out  where to place them proudly!

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