GNU Radio for Android

I have been slowly pushing out information here and there on my work on Android. I've been able to show it off at various conferences and workshops that I've attended over the past few months. It gets a lot of very positive feedback, and we know there are many, many exciting things we as a community of developers and wireless experts can do with this kind of a system.

It's time to start really pushing this project. I spent so much time getting things to work under the hood that I've completely lost track of any of the cool applications that I wanted to work on with it! But the more people that get access to this and know how to work with it, the more interesting the application space and possibilities will become. Because of that, I had been waiting for two things to finish before writing this post. First, I wanted to be able to use a bus-powered Ettus Research USRP with and Android device. And second, I wanted the process documented from the start of building the dependencies to the end of a working (if overly simple) app. Both of those are done.

To help get things started, I've created an Android support page on the gnuradio.org wiki:

• http://gnuradio.org/redmine/projects/gnuradio/wiki/Android

This page is designed to walk a developer through all of the stages from building the dependencies to GNU Radio itself, GRAnd, UHD, RTL-SDR, and gr-omsosdr. This should be pretty much copy-and-paste to get everything built and ready. The final part was finished just today: a walk-through for how to build a basic Android application that launches a GNU Radio flowgraph. This is done using Android Studio, which is the latest development environment for building Android apps. The project can be downloaded from it's Github page to provide a template to set up your own project and verify a working installation:

• https://github.com/trondeau/GrTemplate

Hopefully, we will continue to evolve the process to make setup and building apps easier in the future. The next step is walking through and providing the annoying boilerplate stuff for hardware access so you can start using USRPs and RTL-SDRs with your devices. But for right now, I want to make sure people who are excited about this stuff have a way to get in and start playing.

List of what we support on Android

So where do we stand with our GNU Radio support on Android?

• GNU Radio components:
  • Runtime, VOLK, Blocks, FFT, Filter, Analog, Digital, UHD
  • ControlPort
• Extras
  • gr-osmosdr including RTL-SDR and UHD support
    • HackRF support should be trivial but not done, yet
  • gr-grand: GRAnd (GNU Radio for Android) to support Android-specific I/O and capabilities such as:
    • audio input and output
    • shared buffers between app and flowgraph
    • sensors (e.g., accelerometer and luminosity)
• Tested hardware
  • RTL-SDRs
  • USRP B200 and B210 (the latter required external power on a Nexus 7)
• Android Version
  • Android Lollipop 5.0 or greater. Tested on 5.1.1
    • some complex support in previous versions is lacking in the ndk; we think we can get around it, just not out-of-the-box.

Updates and updates and updates

This blog has been rather silent lately, but that's not because there's not enough to talk about in the GNU Radio world. In fact, there's simply been too much! We've been too busy with events, adding new features, improving old features, and adding new website info that I keep forgetting to update here.

First, you can see for yourself the things that have been going on with the GNU Radio Project at the Events page. We just had hackfest at TU Delft that went quite well followed by another successful SDR Dev Room at FOSDEM. A Couple of the videos for that event are already online.

Meanwhile, coming up, we have:

• A hackfest hosted by Ettus Research.
• A GNU Radio Hacking Workshop before NEWSDR (details to come).
• A FOSS and GNU Radio session at the Wireless@VT Symposium.
• SRIF 2015 with Mobicom (details to come).
• GRCon15 (we're very close to announcing a date and location).

And fred harris and I are teaching another SDR class with the UCLA Extension program.

We have also announced our plans for the 3.7.7 release of GNU Radio, which will now include VOLK as a separate library.

And the GNU Radio community has been working hard on improving our websites. We are near to a release of our new CGRAN website, which now ties in nicely with PyBOMBS and will help us keep up-to-date with everything better. And we are working on a new front page for gnuradio.org. You know how you've hated being dumped into that Redmine wiki page? Well, that will still hang around as the developer's portal, but we want our main page to be more user friendly and to address the GNU Radio project as a whole, including GRCon and other events and where to find users and use cases of GNU Radio.

Along with all of this, we've been working on a number of features. I'll spend more time on each of these later, but wanted to get the word out there.

• Support for GNU Radio applications on Android. I'm calling this an alpha release since there's still lots to do to make things work smoothly here.
• Reviving ControlPort functionality by using the Apache Thrift project. We're close to having this merged into master, but the branch is up on my github page.
• Providing improved packet-based and burst digital signals. Again, a work-in-progress with the branch up on my github page.
• Adding sample rate and timing info on a per-item basis in a flowgraph. This will allow a block to ask for the exact time stamp of any item, and it provides a global understanding of the sample rate of each block. The code on my public branch works, but I have a better idea how to handle things when sample rates change during runtime.
• Improving our QA testing and continuous integration services. I've been rolling out a Jenkins server in my office (for now) that manages a handful of different nodes for different purposes. I have a box with the minimum dependencies we require for GNU Radio to make sure we're not moving past them as well as testing on various other things like OS X and 64/32-bit installs. And I even have a system testing our embedded SDK cross-compiler with on-board testing of the QA to see what breaks there. This will help ease my mind of missing something or overlooking some problems. I'll get weekly reports but can also kick off these tests whenever we need to get a state of the project.

I think that wraps up the main points of the project that we're working on. I'll update again with details of some of these projects when they've rolled out more fully, especially on the Android, ControlPort, the website, and GRCon items.