Source: http://wiki.lemaker.org/WiFi

AP mode:

• Wifi AP mode
  edit /etc/modules: ap6210 op_mode=2
• download and compile the hostapd
  git clone git://w1.fi/srv/git/hostap.git
  apt-get install libnl-dev
  cd hostap/hostapd
  cp defconfig .config
  make
  cp hostapd /usr/local/bin
• create and edit the hostapd.conf
  mkdir -p /etc/hostapd edit:

interface=wlanx
driver=nl80211
ssid=ap6210_ap_test
channel=6
hw_mode=g
macaddr_acl=0
auth_algs=1
ignore_broadcast_ssid=0
wpa=3
wpa_passphrase=12345678
wpa_key_mgmt=WPA-PSK
wpa_pairwise=TKIP
rsn_pairwise=CCMP

/etc/network/interfaces

auto lo
iface lo inet loopback
iface eth0 inet dhcp

allow-hotplug wlanx
iface wlanx inet static
address 192.168.100.1
netmask 255.255.255.0

apt-get install udhcpd

/etc/udhcpd.conf

interface wlanx

option subnet 255.255.255.0
opt router 192.168.100.1
opt wins 192.168.100.1
option dns 192.168.100.1
option domain local
option lease 86400

udhcpd /etc/udhcpd.conf
hostapd -B /etc/hostapd/hostapd.conf

iwconfig