[7 Oct 2013]: All interfaces confirmed working

We’ve had confirmation for a few weeks that all interfaces are now working. There are a couple of modifications that would be nice to have made: most of these for a 2.5k run can be done with flying leads. We are now waiting for the MEB schematics to be made available so that they can be reviewed.

[July 15, 2013] First Batch (Group photo)

The A20 CPU Card first batch is now ready for shipping. They’re to be picked up and then sent out shortly. Thank you to the 20 Free Software developers brave enough to take one of these at this very early phase. The picture below is one from a desk at Wits Tech’s offices.




Please note: this EOMA68 CPU Card will come with an A20 CPU because pricing is the same. If an A10 is specifically needed, it can be made available by special order.

eoma68 a20 demo [lkcl YouTube channel, July 2, 2013]

Rhombus Tech EOMA-68 Initiative [lkcl YouTube channel, May 6, 2013]

Short video describing the benefits of EOMA-68 CPU Cards

[Dec 18, 2012] Or a PCMCIA card size SOM boosting the industry.
Source: Rhombus-Tech / allwinner a10 / news
14 Dec 2012: First Revision EOMA-68 Sample CPU Card

Many thanks to Wits Tech for sending the sample all the way over from China, it arrived today.


Allwinner A31 – ARM Cortex A7 Quad-Core SoC [Rhombus-Tech, April 2, 2013]

… If you would like to register your interest in an EOMA-68 CPU card with an Allwinner A31 CPU, please follow the instructions at the orders page. … Unsurprisingly, this CPU has been chosen as the first CPU for an EOMA-68 CPU module. The critical decisive factor however was the immediate support of Allwinner’s Board of Directors for releasing full GPL Source Code, to help the RHT Initiative to foster better relations and closer ties with Free Software Developers. …

Rhombus-Tech/ allwinner/ a31/ news

4 Apr 2013: Preliminary PCB layout: components fit

With some guesses as to the size of the AXP221, the layout has been roughly completed, components placed, and power planes begun. Manual work on laying out copper pads for the AXP221 cannot begin however until its size is confirmed. However there is still quite a lot left to do, such as setting up the Design Rules for the auto router to complete the LCD, HDMI, NAND, SD, SATA. Ethernet etc. This is also progressing well.

4 Apr 2013: Preliminary PCB layout nearly completed

Approximate layout (placement) almost done – the bit that’s missing is the AXP221. With no datasheet or PADS layout that’s the main thing which is holding things up. With little experience at this, it’s hard to tell if the idea of overlapping the SATA IC with the Ethernet IC is a good idea. We shall see!

2 Apr 2013: PCB layout started

A very rough layout has begun, and the process of synchronising the PCB layout with the schematics has started. Approximate positioning shows already that this is achievable, although it may be a little tight on the PMIC side. The bottom left corner is reserved for the AXP221. The connectors are to be placed in exactly the same locations as for the A10/20 and iMX6 CPU Cards.

Thanks to Allwinner for providing the DDR3 RAM layout, this CPU Card will have four 16-bit-wide DDR3 RAM ICs, in two separate banks providing a total 64-bit-wide memory access (similar to the iMX6 CPU Card). The provision of this pre-tested layout will greatly accelerate the time to completion of the PCB.

31 Mar 2013: Schematics, PCB layout and GPL Source code received

After discovering the low-cost JM20329 USB-to-SATA IC, the creation of an A31 EOMA-68 CPU Card made a lot of sense. A request to Allwinner for example schematics, PCB layout for the DDR3 RAM section, GPL kernel source code and u-boot source code was sorted out within under 24 hours – thank you!

Due to the parts having been sourced and the parts created for other projects, the first revision of the A10 EOMA-68 Schematics was sorted out in a little under four hours. The PCB will however take a little longer!

Rhombus-Tech / allwinner a10 / news

31 Mar 2013: Images of A10 PCB

Thanks to Wits-Tech, here’s a screen-shot of the PCB that went to the factory for printing and component population 10 days ago: it should be back very shortly. We’ve arranged for 5 samples, one of which will have an A20 CPU.

23 Mar 2013: Litkconn show PCB and Case match up

Litkconn and Wits-Tech very kindly helped to confirm that the PCB size is now correct, and that it’s practical to fit the PCB into the case. The plastic of P/N CH-PC-20 has been cut (the end removed) and a new one will need to be made. The current thinking is to create a 1.5mm thick aluminium stamped plate from sheet metal that, as part of the stamping process curls the ends inwards, to clip into the plastic edges left and right. It will also be glued (to the metal tabs) and then just for paranoia a sticky label wrapped around the whole lot, with the Serial Number on it. Clearance above the Micro-SD Card and Micro-HDMI is only 0.7mm: plastic isn’t going to cut the mustard.


The PCB design was actually completely re-done, hence it took slightly longer than strictly necessary. This included re-laying-out the Micro-HDMI and Micro-USB parts, and hilariously the PCB designer got them the wrong way round again. However due to the prior experience it was possible to check this before the PCB went out. …

End of updates

More information:
preorders from Rhombus-Tech (I have neither affiliation to them nor business interest in these cards)
– in the The upcoming Chinese tablet and device invasion lead by the Allwinner SoCs [this same blog, Dec 4, 2012] post
– all details: in section “7. Possible further hardware advances sustaining this new trajectory” of the $99 Android 4.0.3 7” IPS tablet with an Allwinner SoC capable of 2160p Quad HD and built-in HDMI–another inflection point, from China again [‘Experiencing the Cloud’ blog, Dec 3, 2012] post


  1. Allwinner is not listing this card on its site (as of Dec 18, 2012), however you can find all currently available cards on its site as Dev-Kits (starting actually with Pro A10 Kit). It is easy to compare those cards in size by comparing them based on the picture size of the A10/A13 SoC on each of the cards relative to this EOMA-68. The target manufacturing cost of EOMA-68 for Rhombus-Tech is $15 when there will be orders for 100K units taken altogether (see Rhombus-Tech FAQ). In the end (as the result of all that, i.e. smaller package and target 100K orders) Rhombus-Tech’s price should be much lower than e.g. the price of A10-Cubieboard which was selling for $49 + shipping (see: Android-powered Cubieboard is already sold out [TG Daily, Sept 11, 2012], and the “sold-out” status is still the case). This is explicitly indicated by Rhombus-Tech in the pricing section of its preorder page as:
    1. Regarding pricing: the hardware NREs from the factory are $USD 2,000. Therefore, based on the number of committments so far (23 as of 2011Dec12), pricing looks set to be around $100. By the time the number of preorders reaches 30, that will be around $75 (30 reached as of 2011Dec17). (Update: as of 2012Mar01 the alpha units have reached 141 and it’s down to $41 per unit assuming NREs of $2,000 and component costs of $30. Please note: we do not yet know the unit cost! this is entirely preliminary!).
    2. The mass-volume (100k units) cost will be somewhere around $15: the more committments received, the closer the price will get to that. One expression of interest has been received for 1,000 (stable) units: a pricing evaluation request is outstanding with the factory and will be reported as soon as it is received.
    3. Please note: this cost excludes a case, power supply, packaging, shipping, tax, customs and import duty. and profit.
  2. I made a rough calculation of pre-orders two months ago, and found that:

    [committments so far:
    – 23 as of Dec 12, 2011
    – 30 as of Dec 17, 2011
    – 141 alpha units as of Mar 01, 2012
    large (=5 or more) number of units on preorder after Mar 01:
    215= 43×5
    so the whole project looks quite feasible from the point of view of achieving the $15 unit cost for which 100K units should be on order
    as it was already included in section “7. Possible further hardware advances sustaining this new trajectory” of the $99 Android 4.0.3 7” IPS tablet with an Allwinner SoC capable of 2160p Quad HD and built-in HDMI–another inflection point, from China again [‘Experiencing the Cloud’ blog, Dec 3, 2012] post

2 thoughts on “EOMA-68

  1. Pingback: Allwinner roundup — China Sourcing Fair 2013 Hong Kong | USD 99 Allwinner

  2. Pingback: Allwinner interest in 2013 | USD 99 Allwinner

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