Compiled Executables for the Raspberry Pi

The purpose of this repository is to facilitate testing the concepts presented with mbaigo.

This repository contains mbaigo systems that have been cross-compiled for the Raspberry Pi (with a 64 bit operating system). The Raspberry Pi was selected as the platform because it effectively demonstrates the potential of edge computing. Additionally, using a Raspberry Pi enhances security by isolating the system from personal computers. This reduces the risk of exposing sensitive data, prevents unauthorized access to personal files or applications, and limits the impact of potential vulnerabilities by confining operations to a dedicated, purpose-built device. The Raspberry Pi's small footprint and customizable environment further contribute to a secure and controlled deployment setup.

Solution Deployment

• Note: Each system must be in its own directory.
• Note: Each system must be executable.

You can either clone the entire repository and then move each program to its own directory, or download each program individually and place it in its respective directory. For example, to download the thermostat_rpi64 system:

mkdir thermostat
cd thermostat
wget https://github.com/sdoque/rpiExec/raw/main/thermostat/thermostat_rpi64

The program must be an executable. You can verify this by typing ls -l. In the Unix file permissions, the output should include at least one x, indicating execute permissions. For a typical executable file, the permissions might look like -rwxr-xr-x, where:

• r indicates read permission.
• w indicates write permission.
• x indicates execute permission.

If the file does not have execute permission, you can change its permissions using the following command:

chmod +x thermostat_rpi64

You can confirm the mode has changed by repeating the listing command (ls -l).

Running the Program

The program must be started from the terminal (Command Line Interface) by typing:

./thermostat_rpi64

The first time the program runs, it creates a systemconfig.json file. This file should be updated with the necessary configuration settings. On subsequent runs, the system starts and provides you with the address of its web server. You can access this address using a web browser to verify your setup.

There are two scripts that start and stop respectively the systems to demonstrate a climate control solution.

Remote Operation

If you are operating your Raspberry Pi remotely (e.g., from your laptop), you can use ssh to log in to the device.

To manage multiple systems from a single terminal session and ensure they continue running even after disconnecting from the Raspberry Pi, use the screen utility or the tmux utility. This allows you to create persistent sessions for each system, providing flexibility and reliability for remote operations.

Cloning the repository

For a rapid evaluation of the demonstration, on can clone the latest push of the rpiExec repository with

git clone --depth 1 https://github.com/sdoque/rpiExec.git

If you have already cloned the repository, you might want to update it to the latest version. You can do that with

cd rpiExec
git fetch --depth=1
git reset --hard origin/main

The programs should be executable, but if for some odd reason they are not you will then have to change the program files permission to be executable one, which can be done with one command. You want to execute the command from the rpiExec directory where the subdirectories are located and target files ending with _rpi64, you can use the following command:

find . -type f -name '*_rpi64' -exec chmod +x {} \;

Explanation

• .: Specifies the current directory (rpiExec) as the starting point for the search.
• -type f: Ensures that only files are targeted, not directories.
• -name '*_rpi64': Matches files that end with _rpi64.
• -exec chmod +x {} \;: Makes each matching file executable.

Screen

Screen is a comprehensive window manager that facilitates the simultaneous execution of multiple processes on a physical terminal. This enables us to initiate and maintain the operation of various systems concurrently.

Screen is not installed by default. To add the program execute

sudo apt-get install screen

For instance, we can consider the Service Registrar as an example, commencing from the rpiExec directory.

screen -S esr

where -S esrNaming the window session as “esr” creates a new “window” or view where one can initiate the system of interest.

cd esr
./esr

To detach from this window while leaving it running and return to the terminal, one must first type [Ctrl + A]Subsequently, type the desired text. DTo detach, one returns to the original terminal view. To list all the windows created, one types: screen -lsTo return to a specific window, one types the window’s title. screen -r esrIn the context of the assigned name of the desired window, denoted as esr,

Scripts

It might get a bit annoying to start up all the systems, especially with screen. One can then use the two scripts found in the repository:

• startClimateControl.sh
• stopClimateControl.sh

One must make sure that they have executable file permissions (i.e., chmod +x filename). The scripts require that one has the same file organization as the repository (and they can be modified to fit other needs). To be fully operational, one would also need a temperature sensor although that is not necessary to evaluate the concepts.

tmux

tumx is a terminal multiplexer and an alternative to screen. It must be installed on the Raspberry Pi since it is not there by default.

sudo apt update
sudo apt install tmux

To move between panes press Ctrl+b and then use the arrow key in the direction of the desired pane.

Scripts

There are three scripts to use tmux.

• setupTmux.sh, which setups the session, window, and panes.
• startTmuxSystems.sh, which starts the systems across the different panes.
• stopTmuxSystems.sh, which shuts systems down and 5 seconds later kills the tmux session.