Earthquake Detection Unit

About the project.

Earthquake Detection Unit (EDU) is a simple earthquake detector for the BeagleBone Green equipped with the Zen cape and the SW-420 vibration sensor. EDU attempts to approximately map the vibrations it detects to the Richter scale. The computed magnitude is then displayed on the 14-segment digit display. The digit display is reset back to zero after a prolonged period of inactivity, and the previously displayed value is logged in the ~/edu-logs/ directory. The logging files follow the naming convention edu__MM-DD-YYYY__HH-MM-SS.log, where the date and time specified in the file name is the date and time at which EDU was launched.

Installing prerequisites.

Begin by installing the necessary compilation tools.

$ sudo apt-get install build-essential
$ sudo apt-get install gcc-arm-linux-gnueabihf
$ sudo apt-get install g++-arm-linux-gnueabihf
$ sudo apt-get install binutils-arm-linux-gnueabihf
$ sudo apt-get install cmake

You may need to edit lines 4 and 5 of the edu_toolchain.cmake file to specify the paths of the C/C++ cross compilers.

Building the project.

In the EDU source code directory, create a build directory and change to it.

$ mkdir build && cd build

Set the source and build directory for CMake.

$ cmake ..

Finally, build the project.

$ make

The program executable is titled edu, located in the build directory. There are several tests in the build/Tests directory used to debug various components of the project.

Running the code.

In order for the BeagleBone to obtain the compiled binaries and run them, we set up a Network File Sharing (NFS) server using Ethernet over USB. Start by installing the NFS server program on the host computer.

$ sudo apt-get install portmap nfs-kernel-server

Next, we configure the server by appending a line to the /etc/exports file by specifying the build directory, the USB IP address and the netmask. In my case, since my EDU project folder is in the home directory, I would write the following.

/home/vmishel/EarthquakeDetectionUnit/build 192.168.7.0/255.255.255.252(rw,sync,no_subtree_check)

Restart the server so that our changes to /etc/exports can take effect.

$ sudo exportfs -rav
$ sudo /etc/init.d/nfs-kernel-server restart

Check to make sure that the correct directory is exported.

$ showmount -e

Now we must mount the NFS server on the BeagleBone. First create a mount point.

$ sudo mkdir /mnt/edu-remote-build