The Raspberry Pi can be configured as a Wi-Fi Access Point. This is useful when the Raspberry Pi doesn’t have access to a wifi network and you want to connect to it locally. In this tutorial, we’ll look at how to configure the Raspberry Pi to generate its own WiFi network.

Hardware

• Raspberry Pi (3B+, 4)
• 32GB SD card
• Power supply 5V 3A
• HDMI monitor+keyboard+mouse or remote access (SSH, VNC, NoMachine)

Installing packages for access point configuration

Update distribution

sudo apt update && sudo apt upgrade

To configure the access point, the following packages must be installed

sudo apt install hostapd dnsmasq

You can then unmask and activate the hostapd service

sudo systemctl unmask hostapd
sudo systemctl enable hostapd

For the rest of this tutorial, we need to choose a fixed IP address for the Raspberry Pi. Here, we choose 10.142.2.1

Headless Raspberry Pi configuration

• Configure wpa_supplicant

sudo nano /etc/wpa_supplicant/wpa_supplicant.conf

ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1
country=FR

network={
	ssid="NETWORK-NAME"
	psk="NETWORK-PWD"
}

• Configure dhcpcd

sudo nano /etc/dhcpcd.conf

# RaspAP default configuration
hostname
clientid
persistent
option rapid_commit
option domain_name_servers, domain_name, domain_search, host_name
option classless_static_routes
option ntp_servers
require dhcp_server_identifier
slaac private

# RaspAP wlan0 configuration
interface wlan0
    static ip_address=10.142.2.1/24
    nohook wpa_supplicant

• configure hostapd

sudo nano /etc/hostapd/hostapd.conf

interface=wlan0
ssid=NETWORK-NAME
wpa_passphrase=NETWORK-PWD
country_code=FR
wpa=2
wpa_key_mgmt=WPA-PSK
wpa_pairwise=TKIP CCMP
wpa_pairwise=CCMP
driver=nl80211
hw_mode=g
channel=7
wmm_enabled=0
macaddr_acl=0
auth_algs=1
ignore_broadcast_ssid=0
## RaspAP wireless client AP mode
#interface=uap0

## RaspAP bridge AP mode (disabled by default)
#bridge=br0

To activate the hostapd service, you need to specify the path to the configuration file

sudo nano /etc/default/hostapd

Uncomment the DAEMON-CONF line and add the path to the configuration file

DAEMON_CONF="/etc/hostapd/hostapd.conf"

• configure dnsmasq

In the dnsmasq.conf file, we’ll specify a set of available IP addresses

sudo nano /etc/dnsmasq.conf

interface=wlan0
dhcp-range=10.142.2.10,10.142.2.200,255.255.255.0,24h
domain=wlan
address=/gw.wlan/10.142.2.1

You can then reboot your Raspberry to activate the access point. The icon with the opposite arrows should appear on the Raspberry desktop.

And the access point should be available on devices within network range.

Order summary

sudo apt update && sudo apt upgrade
sudo apt install hostapd dnsmasq
sudo nano /etc/wpa_supplicant/wpa_supplicant.conf
sudo nano /etc/dhcpcd.conf
sudo nano /etc/hostapd/hostapd.conf
sudo nano /etc/default/hostapd

Bonus: Choose a local alias for your IP address

Once our Access Point has been created, we can give your IP address an alias. This allows you to type a URL (domain.com) instead of the IP address to access the Raspberry Pi.

To create a local alias, we’ll define the alias in two different files and link it to the IP address

•  In /etc/dnsmasq.conf

sudo nano /etc/dnsmasq.conf

At the end of the file, add the following line with your IP address and the desired domain name

cname=mydomain.com, 10.142.2.1

• In file /etc/hosts

sudo nano /etc/hosts

At the end of the file, copy the following line with your IP address and the desired domain name

10.142.2.1 mydomain.com

After rebooting the Raspberry Pi, you can check the configuration by connecting via SSH (remembering to connect to the Raspberry Pi access point).

ssh pi@mydomain.com

This procedure comes in very handy when you want to create a local Web Server on your Raspberry Pi. This can allow you to access a web page, hosted on the Raspberry Pi and served by Flask, by typing a URL into your web browser while connected to the same network.

Sources

• RPi configuration
• Raspberry Pi installation