Running a Standalone App on Raspberry Pi with Local WiFi AP (Debian/Raspbian): Setting Up a Web Server

Prerequisites

Before we begin, ensure that you have the following:

• A Raspberry Pi board with Debian or Raspbian installed
• A monitor, keyboard, and mouse (for initial setup)
• A Wi-Fi router and network credentials

Step 1: Setting Up a Local Wi-Fi Access Point

To create a local Wi-Fi access point, follow these steps:

Step 1.1: Install Hostapd and iw

First, update the package list and install the required packages:

sudo apt update
 sudo apt install hostapd iw

Step 1.2: Configure Hostapd

Create a new configuration file for Hostapd:

sudo nano /etc/hostapd/hostapd.conf

Add the following content:

interface wlan0
 ssid My_WiFi_AP
 wpa_passphrase My_Password
 wpa_key_mgmt WPA-PSK
 wpa_pairwise CCMP TKIP
 wpa_group_cipher TKIP

Step 1.3: Enable and Start Hostapd

Enable and start the Hostapd service:

sudo systemctl enable hostapd
 sudo systemctl start hostapd

Step 2: Installing and Configuring a Web Server

We will use the Lighttpd web server for this tutorial:

Step 2.1: Install Lighttpd

Install Lighttpd:

sudo apt install lighttpd

Step 2.2: Configure Lighttpd

Create a new configuration file for Lighttpd:

sudo nano /etc/lighttpd/conf.d/00-info.conf

Add the following content:

server.modules += ("mod_fastcgi")
 fastcgi.server = ( "/" => ( ( "host" => "127.0.0.1"
                             , "port" => 8000
                             , "check-local" => "disable"
                             )
                         )
)

Step 2.3: Enable and Start Lighttpd

Enable and start the Lighttpd service:

sudo systemctl enable lighttpd
 sudo systemctl start lighttpd

Step 3: Running Your Standalone App

To run your standalone app and display the results through the web server:

Step 3.1: Install and Configure FastCGI

Install FastCGI:

sudo apt install libfastcgi-dev libfastcgi++2 libfcgi-dev

Step 3.2: Compile and Install Your App

Compile and install your app using FastCGI:

# Replace 'your_app' with the name of your app
 g++ your_app.cpp -o your_app -g -O2 -I/usr/include/fcgi
 sudo make install

Step 3.3: Run Your App

Start your app:

sudo nohup /usr/sbin/fcgi-exec your_app &

Accessing Your App

Access your app through the web server by connecting to the Raspberry Pi's local Wi-Fi access point using a web browser:

Summary:

In this article, we covered how to run a standalone app on a Raspberry Pi with Debian or Raspbian and set up a local Wi-Fi access point. We also showed how to display the app results through a web server using Lighttpd and FastCGI.

References

• Raspberry Pi - Setting up a wireless access point
• Raspberry Pi - Installing Debian
• Raspberry Pi - Hostapd
• Raspberry Pi - Lighttpd
• FastCGI