This is a service-only application used to program and set up access to USRP hardware on Android devices. Specifically, the USRP B2xx series over USB needs USB permissions and to have the firmware and FPGA images programmed when first powered on. This applications is designed to listen for a new USRP hardware device connected over USB and make sure it is programmed and enabled for other GNU Radio applications to use.
Programming happens in two stages. First, the device's firmware image must be installed. When first run, the program will ask the user for permission to use the USB device with this application;
"SDR HW Setup Open SDR HW Setup when this USB device is connected?"
Check the "Use by default of this USB device" and click ok. It will then load the USRP's firmware image, which actually changes the device as far as the system is concerned. It should then ask again for permission to use the device. Again, click to use by default and OK. It will then go to the second stage and install the FPGA image onto the device.
This is an application that really only runs a service in the background. Once the service is launched, the application kills itself and lets the service continue. It produces notifications in the notification bar, which you will see as the GNU Radio logo. Looking at this, it will provide messages about the current behavior. If everything is working well, it will say that it is:
- loading the firmware
- that loading the firmware is done
- that the firmware is loaded and it is now programming the FPGA
If something goes wrong, it may either get stuck in one of these states or lose connection to the USB device, at which point it will provide a USB error message in the notification area. This last is easily triggered when trying to run the app by hand when a UHD device is not plugged in.
Another intermittent issue observed is that the firmware is loaded correctly but the program never moves on to load the FPGA image. The notification bar will just keep saying it is loading the firmware, which only takes a few seconds. If this happens, just unplug and replug the USRP and watch to make sure it continues on to the FPGA programming part this time.
This application only interacts with the UHD devices over USB, but it still requires a few libraries to be built through the Android NDK. We have instructions for building the necessary dependencies for GNU Radio applications. For this program, we only need a subset of them, including:
- Boost
- libusb
- UHD
For Boost, see http://gnuradio.org/redmine/projects/gnuradio/wiki/GRAndDeps. And for libusb and the UHD library, see http://gnuradio.org/redmine/projects/gnuradio/wiki/GRAndRFE.
When following the instructions, the JNI setup in this application, controlled by GrAndroid.mk, assumes that the installation PREFIX is /opt/grandroid. If you use a different prefix, amend then line in GrAndroid.mk:
GRLIBPATH := /opt/grandroid/lib