Prerequisites

• RK3568 or RK3588 development board
• Ubuntu or Debian operating system
• AP6275S Wi-Fi module (or compatible)

Setting Up Hostapd for AP Mode

Install Hostapd

sudo apt update
sudo apt install hostapd

Configure Hostapd

Create the configurasion file at /etc/hostapd/hostapd.conf:

interface=wlan0
driver=nl80211
ssid=EmbeddedAP
hw_mode=a
channel=36
wmm_enabled=0
macaddr_acl=0
auth_algs=1
ignore_broadcast_ssid=0
wpa=2
wpa_passphrase=SecurePass123
wpa_key_mgmt=WPA-PSK
wpa_pairwise=TKIP
rsn_pairwise=CCMP

Modify /etc/default/hostapd to specify the configuration path:

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

Enable and start the service:

sudo systemctl unmask hostapd
sudo systemctl restart hostapd

Configuring DHCP Server

Install DHCP Server

sudo apt install isc-dhcp-server

Assign Static IP to WLAN Interface

sudo ifconfig wlan0 192.168.50.1 netmask 255.255.255.0

Conifgure DHCP Server Interface

Edit /etc/default/isc-dhcp-server:

INTERFACESv4="wlan0"

Define DHCP Pool

Update /etc/dhcp/dhcpd.conf with a subnet declaration:

subnet 192.168.50.0 netmask 255.255.255.0 {
    range 192.168.50.100 192.168.50.150;
    option routers 192.168.50.1;
    option domain-name-servers 8.8.8.8, 8.8.4.4;
}

Start DHCP Service

sudo systemctl restart isc-dhcp-server

Verify the interface configuration:

ifconfig wlan0

Enabling Internet Sharing

To share the Ethernet connection (eth1) through the Wi-Fi hotspot:

# Enable IP forwarding
sudo sysctl -w net.ipv4.ip_forward=1
echo "net.ipv4.ip_forward=1" | sudo tee -a /etc/sysctl.conf

# Configure NAT masquerading
sudo iptables -t nat -A POSTROUTING -o eth1 -j MASQUERADE

# Set up forwarding rules
sudo iptables -A FORWARD -i eth1 -o wlan0 -m state --state RELATED,ESTABLISHED -j ACCEPT
sudo iptables -A FORWARD -i wlan0 -o eth1 -j ACCEPT