This guide assumes that you have already set up an access point deamon with DHCP Serving enabled

If not, you can follow this guide

Configuration details (from original guide)

  • The SoftAP needs to be active most of the time, since it needs to send beacons every beacon_int (default 100 Tu = 102 ms), with a DTIM present in the beacon every dtim_interval (1 DTIM sent every beacon_int*dtim_interval)

  • To avoid possible issues due to beacons from the SoftAP and from the AP being transmitted simultaneously, we recommend slightly changing the beacon_int in hostapd.conf file. A value of 107 or 113 is ok, since these are prime numbers just higher than 100 (considering that the external AP is using 100).

beacon_int=107
dtim_period=1

Adding wlan1 to wlan0

iw dev wlan0 interface add wlan1 type managed

In case you are starting Station on wlan1 before starting SoftAP on wlan0, also execute: ip link set dev wlan0 down

Important Note: ip link set dev wlan0 down is only needed when starting the Station on wlan1 before starting the SoftAP on wlan0, to avoid this error:

Failed to connect to non-global ctrl_ifname: wlan1 error: No such file or directory

Connecting to a network using wpa_supplicant

Simplest method is to use wpa_cli that comes with wpa_supplicant package

  1. Run : wpa_cli
  2. > scan

  3. > scan_results

    At this point you should get a list of available networks

  4. > add_network
  5. > set_network 0 ssid "MYSSID"
  6. > set_network 0 psk "passphrase"
  7. > enable_network 0
  8. > save_config
  9. > quit

At this point you should be connected :

pi@raspberrypi:~ $ ip a

...

5: wlan1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
    link/ether 00:0d:6f:73:93:6a brd ff:ff:ff:ff:ff:ff
    inet 192.168.1.70/24 brd 192.168.1.255 scope global dynamic noprefixroute wlan1
       valid_lft 3593sec preferred_lft 3143sec
    inet6 2a01:e0a:1fa:f170:f1c4:c242:b971:4cde/64 scope global dynamic mngtmpaddr noprefixroute
       valid_lft 86380sec preferred_lft 86380sec
    inet6 fe80::3932:5c26:3ddb:17c4/64 scope link
       valid_lft forever preferred_lft forever

Making it all automatic upon startup

Silicon Labs provides a few sample scripts to perform such a task nicely. In this case we will simply use rc.local :

Add the following line to /etc/rc.local :

sleep 5
iw dev wlan0 interface add wlan1 type managed
sleep 2

If you had previously registered a network using wpa_cli, your device should connect automatically using wlan1.