RT5350F-OLinuXino design is almost complete


RT5350F

 

This one was inspired by the VoCore project which recently ran on Indiegogo.
We have not hear for RT5350F before, but when we saw it we instantly though it’s good candidate for tiny OLinuXino.
RT5350 is nice small MIPS architecture chip running on 360Mhz and specially made for routers.
It have build-in 802.11n WIFI, 5x 10/100 Ethernet MAC+PHYs, 28x GPIOs, 2x UARTs, 1xSPI and 1x I2C.
Perfect for IoT tiny Linux running board collecting data from sensors and logging or sending it to the Cloud.

What we like in VoCore is that they commit to release it as OSHW design, but the schematic they made available on their page have few significant errors compared to the reference design from Ralink, if these errors are intentional or not we do not know, but the schematic they publish will not work for sure and this is not so good sign :)

Another thing is that they decide to use 32MB RAM while the chip can support more, and to make size as small as possible they didn’t break out all Ethernet interfaces.

Also they decided to use chip antenna, which are well known with their bad performance, so probably their design will be with very limited WIFI range.

This is why we decided to make it properly and our preliminary schematic is now complete.

Our version is with 64MB of RAM, 8MB Flash and all RT5350F pins are available on 2x 34 pin 0.1″ step connectors.

We put proven design for PCB antenna + option for external antenna on connector.

The PCB size become 40×40 mm vs. 25 x 25 mm but we think the benefits are more compared to the bigger size.

We probably will have the first prototypes in September taking into account our Summer Break 1-15 of August.

The price of RT5350F-OLinuXino module will be EUR 15 for single quantities and will drop to EUR 10 for 1000 pcs. i.e. less than Arduino but with 64MB RAM, Linux and WIFI on board!

51 Comments (+add yours?)

  1. Radu - Eosif Mihailescu
    Jul 23, 2014 @ 17:49:06

    I want two, please :-) Is there any preorder page?

    Also, how are the Ethernet ports connected (can’t see any in the picture)? Via a daughtercard, maybe?

    Reply

    • OLIMEX Ltd
      Jul 23, 2014 @ 17:55:27

      I’m afraid if we had to add 5x RJ45 connectors on the board the size would go well above 40 x 40 mm :)
      everyone could wire how many he needs on daughter board

      Reply

  2. David
    Jul 23, 2014 @ 18:03:27

    nice one!! i can not wait to hace a couple.

    how this gets linux kernels when flash is still blank? USB, serial, microSD?

    Reply

  3. John Harding
    Jul 23, 2014 @ 18:10:14

    Ooh, ooh, me too! Sounds great. :-)

    Reply

  4. Vassil Kalkov
    Jul 23, 2014 @ 18:39:55

    Reply

  5. Lumpi
    Jul 23, 2014 @ 19:03:09

    Please add an u/fl antenna connector!

    Do you also plan offering a baseboard with USB and Ethernet connectors?

    Maybe this will become my first Olinuxino board :-)
    Will have to see with our customs…

    Reply

  6. Jon Smirl
    Jul 23, 2014 @ 19:36:01

    Tsvetan, I sent you an email about this

    Reply

  7. Luciano Ventura
    Jul 23, 2014 @ 20:39:47

    Antother great project from you guys! Sure I´m going to buy one!

    Reply

  8. rajtantajtan
    Jul 23, 2014 @ 21:02:37

    What schematic errors are there compared to the reference design? Maybe you should help the poor guy with the schematic errors. It’s not easy to be a young player in this business :)

    Reply

  9. sittisak
    Jul 23, 2014 @ 22:09:45

    Looking forward to have this product on my desk!!!

    Reply

  10. thewyliestcoyote
    Jul 23, 2014 @ 22:41:33

    IFA antenna,
    NOOOOOOOOOO!

    would it be possible to make a version with a SMA or a RP-SMA connector?

    Looks awesome and super useful.

    Reply

  11. Todor Yordanov
    Jul 23, 2014 @ 23:12:09

    Don’t forget to add FCC,CE and three unique mac address.

    Reply

    • Lumpi
      Jul 23, 2014 @ 23:50:25

      I prefer it being affordable rather than having fcc, in any case useless outside of the us. CE well what should i say? Its a eval board not an end customer appliance… I doubt olimex is doing worse than the average chineese wifi ap manufacturer… So i think no ofcom will find your signal in between the millions of wlans… Else i have to go and find my hamradio licence ;-)

      Reply

      • Todor Yordanov
        Jul 24, 2014 @ 10:03:06

        If any FCC,EC + MAC’s i can spend 1k per month, if not Palavrov can help me :).

  12. Atanas Palavrov
    Jul 24, 2014 @ 00:06:12

    Six will be even better ;)

    Reply

  13. Vonger
    Jul 24, 2014 @ 03:03:25

    Haha, what is the error on the sch, could I know that?

    Reply

    • OLIMEX Ltd
      Jul 24, 2014 @ 08:43:32

      your public schematic v1.0 have issues with the oscillator, RESET and WIFI part

      this schematic will never work, I hope this is just preliminary and you solved your issues before run production :) but anyway it’s bad thing to publish just your non-working schematics ;) this is not in the OSHW spirit, either publish correct schematic either do not publish anything until you fix all your problems and do not mislead other people who will try to learn from your design

      overlapping RT5350 with the memory chip on back prevent RT chip cooling and will heat excessively the memory on the back. SDRAM memories have problems with high temperatures more than with negative temperatures

      I read that you come from software world, your design attempt is great for novice, please do not take me wrong, I like what you do :) I would not know about RT5350 if I didn’t read about your project

      Reply

      • pyrofer
        Jul 24, 2014 @ 12:40:40

        Is this the error with a 27pF cap that people with the VoCore Alpha were told to fix manually by relocating a cap?

      • Vonger
        Jul 25, 2014 @ 03:07:43

        Why not open yours, now? :D

      • OLIMEX Ltd
        Jul 25, 2014 @ 08:10:18

        no problem at all, we usually open the CAD files as soon as we have tested prototypes, so we make sure what we open is not with errors
        you can check OLinuXino at GitHub there are CAD files for all our other OLinuXino boards

  14. Dave
    Jul 24, 2014 @ 04:54:08

    I’ve been waiting for this board!

    Reply

  15. Julien Zoidberg
    Jul 24, 2014 @ 12:38:39

    Oh yeah; thanks Olimex, that’s a damn cheap board for so many possibilities. I wish I waited before buying a VoCore as I wasn’t expecting the problems you pointed out… unless they fix the design following your suggestions, but I guess it’s too late.

    Reply

    • OLIMEX Ltd
      Jul 24, 2014 @ 17:03:25

      Do not regret for $20 board :) if they have opened their schematics and PCB layout earlier they could get advices earlier, but they are Chinese and so afraid others will copy their design that still can’t set up their mind for Open Source Hardware and cooperation

      Same situation as this project I spotted yesterday: wrtnode.com what they claim is “first and only Open Source Hardware OpenWRT project” – no CAD files though on their web, they claim on their pages they have sold hundreds then put just schematic in PDF format and write “we will eventually upload the PCB files later” :)

      or:

      http://www.lemaker.org/ “Banana Pi is an open-source hardware product.” again no CAD files :)

      I’m afraid VoCore go in the same direction

      Reply

  16. Andromeda
    Jul 24, 2014 @ 13:47:32

    But size does matter so much? ;-) I don’t ask for 5 eth ports (there are plenty of routers if one needs one of them and they are even in a nice box) but a single eth port + a single USB port on the board would make a much more useful board (IMHO). If the board would be 40 x 60 mm where is the trouble?

    Reply

  17. Christopher Campbell
    Jul 24, 2014 @ 14:40:27

    with all the high speed devices will there be a Gbit version?

    Reply

  18. Vonger
    Jul 25, 2014 @ 02:57:33

    The fact is not you think. I want and I will open v1.0 release version, but in China, the situation is a little different. If I public it now, the small company in ShenZhen will make many low quality copys even before my batch done, that is not good.
    And the bug on sch is not intent to do. At least, my version 0.3&0.5 are working very well, and they are totally opened.
    On my blog, I am not only showing the final result, but also want to share the process how I done it. :) From my side, VoCore is not a pcb board but an art.

    Reply

    • OLIMEX Ltd
      Jul 25, 2014 @ 08:14:28

      please read this: http://olimex.wordpress.com/2014/07/15/when-one-project-can-be-named-open-source-hardware/

      if you do not intend to open your CAD files maybe you should remove the OSHW marketing from your pages until you open the files and comply with the OSHW definition?

      I do not buy the copy reasons

      Now when you hide your board design does this stop small companies in China to release RT5350F based boards? There is Ralink reference design for RT5350F which is much more complete than your schematic. Look at taobao there are RT5350F modules like yours starting from RMB 40

      You completely miss why people do OSHW – to share knowledge and build better products, you already had successful funding, sold thousands of boards, promised to people open design (many people may have supported you because of this your decission), but now do not keep your promise for some reasons, this is not correct

      Reply

  19. Vonger
    Jul 25, 2014 @ 03:04:52

    And under that v1.0 sch, I have said that is not the final result…

    Reply

  20. Arie Nap
    Jul 25, 2014 @ 17:37:38

    The inverted F antenna that is on this board does not look well suited to this board as the tip of the antenna folds into the board.

    Do you guys have a network analyzer to measure antenna return loss? Or a spectrum analyzer with a nice reference antenna to do some preliminary antenna performance measurements in an open field ?

    The tuning of the inverted F antenna is very sensitive to the shape and size of the board, transferring an antenna from one board to another sized board will not work as expected! Best practice is to put a 0402 pi filter in front of antenna to retune the antenna for every board.

    Reply

    • OLIMEX Ltd
      Jul 25, 2014 @ 17:51:01

      thanks for the tip we have spectrum analyzer and RF probe, we are going to experiment with different PCB antenna shapes as well

      another issue to think of is the 2.4G frequency tuning, it’s generated by pll from the crystal on the board, and even crystals with 10ppm may cause frequency shift.

      RT5350F have EEPROM where you can write values to adjust the frequency in right value

      professional WIFI testers cost $30K we have to develop something simple for the production test and adjustments

      Reply

      • Arie Nap
        Jul 25, 2014 @ 18:26:20

        I have experience with ZigBee chips and associated antenna design.
        Production tests are always difficult and OEMs usually just buy expensive testers. We have developed our own test system to measure RF power and frequency accuracy, but it is not trivial. Our frequency accuracy measurement is based on a frequency divider followed by a frequency counter.

        Crystal oscillators in RF designs are much more critical compared to other designs. WiFi chips require 25 PPM accuracy. Not sure about the architecture of the RT5350F, but usually you can get away by buying a crystal specifically tuned for the chip with the right load capacitors. Crystal accuracy depends on much more than only the crystal when coming down to 25 PPM. You have to know the load capacitors and the characteristics of the crystal to determine the frequency accuracy. Just buying a 10 PPM crystal and teaming it up with some load capacitors will not get you to 10 PPM. Temperature and aging also cause some extra frequency offset. This means you have to specifically buy some crystals according to your (or Realteks) specification. If you place these crystal you might not need the EEPROM tuning of the crystal. The great advantage of the EEPROM tuning is when you produce very big numbers; then the cost of the tester becomes irrelevant and you can buy some cheaper crystals and dial out the offset of the cheap crystals.

        If you have any further RF application question just shoot me an email or try contacting the chip vendor, I am sure they help you find a suitable crystal with the right load capacitors.

        The antenna always stays your design and the chip vendor can only advice you on that subject, so I do not know how you could tune an antenna without a network analyzer. Spectrum analyzer is great for analyzing the actual performance, but tuning the antenna requires a network analyzer.
        This tutorial describes the hands-on approach on antenna tuning, really a good read (it is the work I do from day to day :) )

        http://colinkarpfinger.com/blog/2010/the-dropouts-guide-to-antenna-design/

  21. Ana
    Jul 25, 2014 @ 22:26:55

    Lots of talk about spirit OSHW and share knowledge, but yours System-On-Module boards no OSHW. Why reason?

    Reply

    • OLIMEX Ltd
      Jul 25, 2014 @ 23:06:52

      When we make OSHW design we make it clear and do it properly.

      We have 600+ products, some of them are OSHW some are not. I do not see anything wrong in this, they have different purposes, serve different goals and different market needs. Where do you see us to say that we will do only OSHW and not closed source projects for customers?

      With the same logic you can ask people who write Free/Open Source Software what is their reason to work on private projects during their day-job. This sounds ridiculous isn’t it?

      I do not mind if people do closed source boards and projects or open ones but it’s not right to use OSHW name just as marketing buzz word, as this wear OSHW meaning and spirit.

      It’s not right to name project OSHW then to not comply with the requirements for OSHW and make excuse for this or that reason.

      Reply

      • Brendan
        Jul 28, 2014 @ 08:50:48

        opensource development is always available pre-final release with lots of bugs (at least in software world). Even final releases have bugs, so I don’t think you can hang the poor guy for that. If it claims to not be tested and based on reference design then that’s enough warning for people to double check the schematic themselves. The spirit of pensource is about getting it out there to the public so that they can contribute back (either features or fixes).

      • OLIMEX Ltd
        Jul 28, 2014 @ 13:58:56

        how do you contribute when there are no sources? just preliminary schematic in non editable PDF format with errors, this guy has run production and he claims the production device is working i.e. he fixed his errors, he do not publish his corrected schematics and hide the CAD sources, but still call his design Open Hardware :)

      • Max
        Jul 29, 2014 @ 01:28:21

        Please don’t take this the wrong way, but what I believe is that the point of Open Source and Open Hardware is indeed to facilitate cooperation for the benefit of all, not to beat others on the head with it, ‘holier-than-thou’ style. Sure, when and if the guy’s been selling his stuff for like half a year with missing documentation, one is entitled to bring that point up – if one really wants to make a case out of it; but nitpicking before he even shipped his first batch is… quite disingenuous, and IMHO not in the OSHW spirit at all. That said, I rather like both designs – kudos to you for deciding to make an OLinuXino based on this chip. I’ll be definitely watching…

  22. The Visitor
    Jul 26, 2014 @ 17:51:52

    It would also be great to see some cheap (about $20) modules like this based on Atheros. Atheros seems to be a bit less awkward, better supported by systems like OpenWRT and haves higher clocks, etc.

    OSHW would be a plus over cheap chinese stuff which is nice and good prices but really sucking at documentation up to degree you have to reverse-engineer most of extension pinout yourself by looking into AR9xxx pdf and tracing PCB tracks to headers, which is time consuming stuff to say the least.

    Reply

    • Lumpi
      Jul 28, 2014 @ 22:31:10

      I ylso would prefer atheros based, but maybe this will be the first ever truely stable and supported ralink/mtk based router.

      35€ is a good price for an experiment! And definitely better than my collection of broken (not bricked) routers…

      Reply

  23. Michele
    Jul 27, 2014 @ 12:39:29

    wow , great Olimex!!! I can not wait to order a 20 pieces.!
    Olimex all life!

    Reply

  24. David
    Jul 29, 2014 @ 10:37:51

    Nice. 2xUART so I can get a serial console and a separate serial port to take GPS NMEA sentences and a 1-PPS signal to discipline NTP. I wonder if I can externally clock the RT5350F SoC with a GPS disciplined clock generator (e.g., very low phase noise SiLabs Si571 chip)? This is a recipe for a very inexpensive yet very high performance NTP time server!

    Reply

  25. Jordi
    Jul 29, 2014 @ 21:25:56

    Please more flash memory. Like carambola2 16MB.

    Reply

  26. gicho
    Aug 11, 2014 @ 10:42:56

    Tsvetan,
    do you have plans to use newer Mediatek products? 5350 is quite old one and it now shows its age – mostly power and heat problems. I have an alpha vocore and the heat is an issue.
    There is a newer alternative – MT7620 – http://www.anz.ru/files/mediatek/MT7620_Datasheet.pdf. Its faster, better wireless, more interfaces and has more features. Comes in either BGA or QFN. Supported in OpenWRT. Chinese module present too.
    Also, there was another SoC from Mediatek but I cannot recall precise number. It was SoC with built in 256Mb of memory (on chip). I know it from vonger’s blog :-).
    Being in position of well known company, you can get more information from mediatek.
    Vonger had made an interesting product but I don’t see Olimex in position to follow after VoCore? Take the lead with better design.
    Have you considered crowdfunding for some projects? If VoCore made 1000% of its goal, I think you will have success too.

    Reply

  27. Stelios
    Sep 22, 2014 @ 23:04:19

    Hello!
    Do we have any progress on this product? Would love to get my hands on a couple of those little boards :-)

    Reply

  28. Trackback: RT5350F-OLinuXino Update | olimex

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