Guidance

Guidance is a navigation system used to provide users with a way of traveling from point A to point B without the need to use their sense of sight or hearing.

To-Do

• Add pybluez to requirements.txt
• Add infrastructure diagram

Getting Started

These instructions will get you a copy of the project up and running on your local machine for development and testing purposes. Note: We use dummy_data.py for testing purposes to simulate the query of some API responding with the next direction and distance until then. Used SOLELY for testing purposes.

Prerequisites

Prior to running this application, ensure that you've followed the steps below to ensure that your distribution of Linux is properly configured.

Using the command line interface, check that your devices bluetooth module is recognized

hciconfig

Afterwards, you will need the following packages in order for pybluez to properly compile on your system.

sudo apt-get install python-dev
sudo apt-get install libbluetooth-dev

Check the status of your bluetooth service. You should see the status as active (running). Thus far, it has been safe to ignore the warning listed below when executing the command.

sudo service bluetooth status

From the previous command, right above active, you should see loaded. Take note of this path and modify the file at this location using your favorite text editor, vim!

vim /lib/systemd/system/bluetooth.service

Under [Service], add the -C flag to the end of the ExecStart alias.

ExecStart=/usr/lib/bluetooth/bluetoothd -C

At this point, reboot your system so the device will recognize the changes.

sudo shutdown -h now

Optional, but highly recommended

You may encounter an error that says

_bluetooth.error: (13, 'Permission denied')

An easy, but not recommended, workaround is to run the script as the root user. We suggest the following. Make sure your pi user is in the bluetooth group.

cat /etc/group | grep bluetooth

If your device is not, add pi to bluetooth group:

sudo usermod -G bluetooth -a pi

Change the group of the /var/run/sdp file:

sudo chgrp bluetooth /var/run/sdp

To make the change persistent after you reboot your device, create the file /etc/systemd/system/var-run-sdp.path with the following content:

[Unit]
Description=Monitor /var/run/sdp

[Install]
WantedBy=bluetooth.service

[Path]
PathExists=/var/run/sdp
Unit=var-run-sdp.service

Also add this file /etc/systemd/system/var-run-sdp.service:

[Unit]
Description=Set permission of /var/run/sdp

[Install]
RequiredBy=var-run-sdp.path

[Service]
Type=simple
ExecStart=/bin/chgrp bluetooth /var/run/sdp

Finally, start everything up:

sudo systemctl daemon-reload
sudo systemctl enable var-run-sdp.path
sudo systemctl enable var-run-sdp.service
sudo systemctl start var-run-sdp.path

Installing

Clone the repository to your desired directory and cd into it.

git clone https://github.com/DarianNwankwo/guidance <desired_location>
cd <desired_location>

Now, create a virtual environment using your preffered method. Here, we'll use the following.

python3 -m venv <venv_name>

Now activate your newly created virtual environment

source <venv_name>/bin/activate

At this point, we can install the required dependencies using pip.

pip install -r requirements.txt

Built With

• PyBluez
• RPi.GPIO
• pexpect

Acknowledgments

• @egorf for providing this application with bluetoothctl.py