Android or Linux for Embedded Systems, Some Thoughts

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• Android or Linux for Embedded Systems, Some
  Thoughts

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While now hard to remember, there was a time when
the term embedded Linux was viewed with
suspicion. The outcrop of small, low-power,
Linux-based devices - and readily available open
source software - has since transformed the
industry nowadays its not why would you run
Linux here but rather - why wouldnt you?
With embedded systems boosting more performance
and graphics capabilities than ever before, and
with GUI-enabled touchscreen devices taking hold
in a wide range of applications, from small
control panels to huge infotainment screens,
Android - once viewed as a purely consumer OS -
is becoming an interesting alternative.
In this post, Antmicro, Toradexs long-time
partner and provider of software product
development services for mutual customers, as
well as the maintainer of Android images for
Toradex modules, explains the differences and
commonalities between those two operating systems.
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Over the years, we have developed numerous
software solutions and complete devices, both
industrial and consumer, running Linux and
Android, and we believe there is no silver bullet
- what OS is better for your use case depends on
the use case itself and your devices planned
life-cycle.
TAQ (Toradex, Antmicro, Qt) self-balancing robot
heterogeneous architecture w/ Linux by Antmicro
on Toradex Colibri i.MX7 SoM
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Linux is a great choice for the majority of
embedded use cases. Linux build systems such as
Buildroot and OpenEmbedded can be used to create
customized BSPs tailored to almost any size and a
wide array of application software and SDKs is
available, from gstreamer through Python to even
node.js. An OpenEmbedded/Yocto-based Linux is the
default distribution supported by Toradex, and a
vast development community supports a multitude
of programming language environments and
frameworks. Modern Graphical User Interfaces
(GUI) can be developed with many technologies
including Qt, HTML5, to the point that can make
it hard to choose. But once you build your base
OS image with the necessary software components,
update capabilities and APIs - a task for which
you also can use service providers like Antmicro
- you have all the freedom in the world to build
your application software, and it is not so hard
to change your mind down the road in case you
need that.
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Android, on the other hand, forgoes some of the
OS-level freedom in favor of standardization
there is an Android way to do things in order
to benefit from the good sides of this OS. In
return, you get a unified GUI framework, Java
programming paradigm and a familiar developer
experience (a natural consequence of Androids
smartphone/consumer origin) which can in fact be
critical for your use case, especially if your
device includes a touchscreen which is intended
for regular use by various people. For example,
if you have an already existing dedicated app for
smartphones/tablets that your users are
accustomed to - whether its a smart home control
center or a mobile industrial measurement device
- and you are building a dedicated device to
replace or complement them, Android is the
perfect choice. Without the need to rebuild your
user interface from scratch, you save vast
amounts of work and numerous user studies to get
the UI right, and people care most about what
they see and interact with.
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You will need an industrialised Android image
(with e.g. single-app lock in, customised
branding and OS abstractions for various
interfaces) to accomplish this, but it will
probably be a smaller investment than recreating
the user experience in Linux. Even if you do not
have a pre-existing app, you may also have an
in-house team of Android application developers
(or know a good Android application design
studio) who could potentially develop your UI for
you. With a much broader application development
community, tons of example apps, standardised
application packaging and emulators, developing
end user apps in Android is easy. The clear
separation between OS and application layer
through standardised APIs (in Android you use
different API levels to indicate compatibility)
means that you can reuse existing mobile apps or
have a separate team work on them and carry on
with testing or adjusting the user interface with
the target users while an embedded team works on
ensuring all the Android features you want to
support.
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Good use cases for choosing Android especially
includes scenarios with a larger, varied
community of users. That includes not only
typical consumer devices such as wearables or
smart home IoT, but also things such as corporate
devices used by industrial professionals in
larger numbers - from hand-held instruments to
networks of machines situated on site. Even
foregoing the application development experience,
the familiar user interface components, gestures
and interactions of Android may be enough to
warrant picking it over Linux.
As mentioned above, Android - although based on
the Linux kernel - has its own way of doing
things, including a fairly complicated
buildsystem (related to its huge codebase), and
the necessity to expose your kernel level
additions to the OS layer in order to make them
work in your application. There are also more
requirements from the hardware - since Android
requires graphics acceleration and memory for its
virtual machine, you will typically not be able
to run modern Android versions on a device with
less than 512 RAM or without a GPU. As with any
other choice, using Android in your embedded
device should be motivated by a need for the
benefits it provides.
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Antmicros Industrial Android running on Toradex
Apalis Tegra K1 SoM
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Antmicro has helped numerous customers choose the
right operating system for their devices based on
Toradex platforms, and provides Android demo
images and development services for Android 5.1
or 6.0 for the Toradex T30/i.MX6 and TK1 modules
to offer better time-to-market. If you need
assistance in deciding which option to pursue for
your next embedded device, Antmicro will be happy
to guide you further. For details please contact
mgielda_at_antmicro.com or visit www.antmicro.com.
you can also use an NDK to develop your
applications in C/C and C, use Qt as your
presentation framework or develop mobile apps
using Javascript in frameworks like Cordova or
React Native - but we are focusing on the most
popular scenario here.
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Thank you