Project Ara MDK FAQ

Questions are ordered from newest to oldest

September 29, 2014

Q: Why did the dates of the first module developer prize challenge change?

A: As we've communicated to our developers, we have had some delays in manufacturing dev boards. We've adjusted the prize challenge deadlines in accordance with the latest estimate for developer hardware shipment.

August 13, 2014

Q: I’ve been contacted and told that I was selected to receive Spiral 1 developer hardware. So where is it?

A: First of all, congratulations. We had a tremendous interest in developer hardware and we regret that we weren’t able to get everyone who wanted (and merited one) a dev board. For those lucky ones, however, we apologize for the delay. The boards are in fabrication and unfortunately encountered a manufacturing defect (the boards were plated with the incorrect material), causing several weeks of rework. We still estimate that developer hardware will ship during the month of October. We will adjust prize challenge timelines accordingly as we definitize the ship dates. Again, we are sorry for the wait. We are just as anxious to get these to you as you are to get them!

Q: I was part of the Ara Research Scout program and am one of the top hundred scouts. I was told I would get an Ara phone. When can I have it?

A: We’d like to extend our thanks to the more than thirty thousand Ara Research Scouts who participated in DScout missions to help support user research for project. Indeed, we promised the top scouts an Ara phone when we get to our market pilot in 2015. We will contact these scouts individually with further details once plans for the market pilot solidify.

Q: If I have some components on the bottom side which wouldn't fit otherwise onto the PCB, am I allowed to mill cavities into the module base as long as it doesn't affect the overall stability/robustness of the module base?

A: Yes, custom milled cavities are allowed in the module base as long as the structural integrity of the module base is maintained and can survive typical usage over the life of the module.

Q: Is the 0.5 mm FR4 PCB a requirement?

A: No, the 0.5 mm FR4 PCB is a reference implementation for the current prototype. There is no specification for the PCB beyond those related to the the interface block(s), which are part of the PCB.

Q: When and how are the EPMs activated upon module insertion?

A: In the current prototype, EPMs are manually activated and deactivated by the user with an Android application. EPM control may be augmented via the supervisory controller and Bridge ASICs; details of these functions will be provided in a future MDK release. Module insertion and EPM control use cases will also be detailed in a future MDK release.

Q: Is there an EPM specification for maximum holding force when in the attach state? Is there a specification for minimum pulse length, maximum energy, and whether the pulse train can be periodic or aperiodic?

A: The maximum holding force for the attach and release states are 30 N and 3 N respectively. There is no specification for the maximum holding force for the attach state; however, the maximum force in the release state should be 3 N to allow users to remove the module easily. The EPM drive timing in the MDK is a reference implementation and not a specification. A different EPM design may use an entirely different drive timing implementation or even entirely different means to operate the EPM.

Q: Do you have near-field EM physics model (e.g., COMSOL) simulations available for the reference EPM design?

A: Yes, we will provide the COMSOL models for the EPMs in the next release of the MDK.

May 29, 2014

Q: When is the prize challenge announcement?

A: We are in the process of finalizing the terms and conditions of the prize challenge. The current schedule is to announce the challenge shortly after the initial dev board release, although the two are separate (i.e., you can get dev boards without competing for the prize and vice versa).

A: Update - The first prize challenge was also officially announced at Google I/O. You can find details about the prize challenge at


Q: When will you release the next version of the MDK and what changes will it include?

A: MDK version 0.11 (alpha) is now available for download. This version includes administrative corrections, updates to the power and thermal specifications based on feedback we’ve received, additional reference materials including module shell and endo CAD files, PCB Gerber files, build instructions for prototype EPMs, and separate sections for known vendors of module components.

Q: Are developers allowed to file patents for their module ideas? How is module IP protected from other module developers?

A: Yes, module developers can file patents for their module ideas. Please see the video from the developer conference that addressed this specific question. Note that the MDK License is the governing legal document and trumps anything in the video or that we say here.

Q: How are the PCB and safety shield mounted to the base? How are EPMs mounted?

A: Mount points and mounting brackets for the PCB, safety shield, and EPMs will be specified in MDK version 0.15 scheduled for release around September. The PCB and safety shield are soldered onto the base in the current version of the prototype.

Q: How will the Metamorphosys tool chain help me develop an Ara module?

A: The Metamorphosys tool chain can be used to rapidly model an Ara module and evaluate design feasibility, performance, and spec compliance. Metamorphosys provides free, open source “glueware” and a common modeling environment across multiple existing (largely free) tools and several new ones that we created (or more precisely, it provides semantic integration across several domain-specific modeling languages commonly used for electronic device design). In other words, module developers can virtually assemble and perform digital, analog, cycle-accurate software, thermal, and other coupled simulations prior to or in conjunction with building and debugging a physical prototype.

Q: How do I get a copy of the Metamorphosys tool chain that was demonstrated at the developers conference?

A: The Metamorphosys tool chain is currently being readied for alpha testing with a small handful of brave developers. If you are interested in early access and would like to participate in the alpha test, please send an email to

Q: Is the Metamorphosys toolchain required to develop an Ara module?

A: Absolutely not. It’s a parallel development from the Ara team that we think will be helpful to Ara developers in the long run, but it is by no means required to create a module.

April 24, 2014

Q: Do I have to participate in the module prize challenge in order to get dev hardware?

A: No, you are not required to participate in the prize challenge to get dev hardware.

Q: Will the MDK include specifications for the endo itself?

A: No, the MDK includes specifications for modules and only addresses interfaces between modules and the endo. Specifications for the endo itself should not be necessary for most module development. However, see below….

Q: Will CAD of the endo be released?

A: Probably. Due to a number of requests, we will likely include the CAD models of the endo with the next MDK release due out in May.

A: Update - CAD of the endo frame is now in the MDK version 0.11 (alpha).

Q: Does the MDK include CAD of the standard module shells?

A: Probably. Although the fulfillment approach is that the module shells will be supplied externally to the module developers to enable aesthetic customization by the user, we have gotten much feedback that it would be useful to have the reference geometry. We will likely include it with the next MDK release due out in May.

A: Update - CAD of the standard module shells is now in the MDK version 0.11 (alpha).

Q: Will the RTL for the UniPro Bridge FPGAs be made available?

A: No, we don’t own the RTL, and so it is proprietary to a third-party vendor. We will make UniPro Bridge FPGAs available as part of developer hardware kits however. And of course you are welcome to buy/build your own UniPro interface. UniPro bridge ASICs should also become available later in 2014.

Q: How do I write software for my prototype module?

A: The prototype software is a customized version of Linaro Android version 13.09, which will made available on a git repository around the time of the developer hardware release. Guidance on writing software for the prototype platform implementation is provided in the MDK, including how to use existing services like I2C or creating a custom Android image with your specific device drivers compiled.

Q: Will slides/videos from developer conference be posted?

A: Slides from the first developer conference will not be released. However, recordings from the livestream will be captioned and made available on

A: Videos from the first developer conference is now on

Q: Are modules that join two endos or attach a flip screen to an endo supported by the MDK?

A: This is not currently allowed by the industrial design language in the MDK. However, the whole purpose of getting a very early MDK draft out was to get developer feedback and adapt. We think some of the concepts out there are pretty cool. And to the extent that they don’t compromise other aspects of the design, e.g., structural integrity, we will try and make sure they are supported by the platform.

Q: Will the EDA files in the MDK be published in Gerber format?

A: Yes, we will publish the EDA files in Gerber format in the next MDK release.

A: Update - Gerber files are now in the MDK version 0.11 (alpha).