dependencies / configs

This code depends on some external libraries, namely SciPy and PyPRUSS. To run this code, your must have/do the following:

• A beaglebone using the latest version of debian (debian 8.7). May need to aqcuire a +4GB SD card.
• version 4.1.x of a non-TI based linux kernel: This code uses the uio_pruss module to control the PRUSS-ICSS. None of the TI kernels contain this module.
• python2.7
• SciPy: Mostly for human interface stuff where plotting is involved. Used in some of the signal processing math too.
• Disable the HDMI Cape on the BBB: This will free up some many of the PRUSS-ICSS pins.
• pypruss: a python wrapper for the c library responsible for sending high level commands to the PRUSS-ICSS.
• pasm: Compiler for the PRU assembly code. Seems to be included with beaglebones manufactured after April.
• beaglebone-universal-io: Collection of scripts that allow user to assign PRUSS.
• Make a cron job for terminal app: This allows seawolf to interact with acoustics without ssh.

To take care of these dependencies, please follow the steps below.

Flash the Beaglebone Black with the latest version of Debian Linux This will install debian 8.7 on the beaglebone.

1. Go to https://beagleboard.org/latest-images, and download the latest IoT image. As of the writing of this README, that would be the link labeled "Debian 8.7 2017-03-19 4GB SD IoT".
2. unzip the .xz file, write the image (the .iso file) to an +4GB SD card, and flash the image to the beaglebone. More detailed instructions on how to flash the beaglebone can be found on the internet.

Ensure that version 4.1.x of a non-TI based linux kernel is running on the BBB The latest images utilize version 4.4.x-ti-... of the linux kernel, which are linux kernel pushed by Texas Instruments (TI). These kernels do not support the UIO_PRUSS module, which the core acoustic code depends on. Per the advice in this thread(https://groups.google.com/forum/#!msg/beagleboard/6vKLJpJoPGY/kc-iW_fbAgAJ), we're going issue the following commands to revert the kernel back to 4.1.x:

 #on BBB through ssh:
 cd /opt/scripts/tools/ 
 git pull 
 sudo ./update_kernel.sh --bone-rt-kernel --lts-4_1 
 sudo reboot #upon reboot, your beaglebone will be running kernel version 4.1.x

(Optional) Make an Installs directory.
You don't have to do this, but it might be nice to have. The installs directory will act as a point of reference in this short guide.

 mkdir ~/Installs/
 cd Installs/

Install SciPy
Installing scipy is easiest if you use apt-get:

sudo apt-get install python-scipy

Install steinkuehler's BBB universal device tree scripts (No longer necessary)

 git clone https://github.com/cdsteinkuehler/beaglebone-universal-io.git
 cd /beaglebone-universal-io/
 make 
 make install

Now you can issue the command "config-pin" from the commandline and use it for easily manipulate some of the IO/Muxes. The boot.py script takes advantage of this. Also, the makefile had several .dtbo files get copied to the firmware directory as well.

Disable the HDMI control
We used to use this adafruit tutorial (https://learn.adafruit.com/setting-up-wifi-with-beaglebone-black/hardware) to disable the HDMI output from the BBB. The relevant part of it is the section labeled "HDMI Port Interference", where it talks about manipulating the uEnv.txt file. The instructions were used to disable the HDMI cape on the BBB (Which frees up a lot of important pins for controlling the ADC). Unfortunately, BBB's software has changed since that tutorial was written, so the steps are no longer the same. The steps below were used on a new BBB in April of 2017, but you should keep in mind that the process may have changed since this guide was last updated.

For reference, here's what was done on the lab BBB:

**Step One**

mkdir /mnt/boot
mount /dev/mmcblk0p1 /mnt/boot/

The problem is that "uEnv.txt", which you need to edit, is no longer located here. I am not sure if this step was necessary, but I wanted to document that we did it. After lots of searching on the internet, we figured out that uEnv.txt is now located in /boot/, so you simply edit it from a new location. Once you open the file, uncomment the line under the heading "##Disable HDMI (v3.8.x). Save the file, reboot the BBB and keep going.

Do not uncomment a line under a heading similar to "Beaglebone Black: HDMI (Audio/Video) disabled: If you do so all four of the user LED's will turn on and you will not be able to ssh in. If that happens, however, don't panic: you may still be able to plug the BBB into your computer and access it as a USB device (use Linux for this). You can then edit the uEnv.txt file from your computer and comment out the line again. The same goes for any line that talks about disabling eMMC. eMMC is the beaglebone's main onboard memory so that would be... less than advisable.

Install Pypruss from source
Go to the Pypruss Bitbucket repository(https://bitbucket.org/intelligentagent/pypruss) and follow their instructions. Pypruss was installed on the lab beaglebone by...

 cd ~/Installs/
 git clone https://bitbucket.org/intelligentagent/pypruss.git  
 cd pypruss
 python setup.py install
 vim ~/.bashrc #Append "export LD_LIBRARY_PATH=/usr/local/lib" to end of file
 source ~/.bashrc

Make a cron job for acoustics terminal
Doing this will get the BBB to run acoustics_terminal.py at startup. With the FT232RL connected and every thing, getting seawolf to communicate with acoustics is only a matter of sending commands out of seawolf's USB port. There will be no ssh/login overhead. To get this to work, simply type

crontab -e
## to end of file, replacing <path_to_proj_dir> with the path to 
## this very directory 
sudo reboot #For the changes to take effect

then append then append the following to the end of the text file.

@reboot python /host_communication/test/acoustics_echoterm &

Replacing with the path to this very directory

After all this, you are totally ready to run the the pinger_finder software. Instructions for how to do this are at the top.