Raspberry Pi Zero W as Internet connected Access Point *and* Wireless Client

README.md

I wanted this capability for various reasons. It's not necessarily stable, because uap0 has to use the same channel as wlan0, and if you're traveling/mobile, wifi channels aren't necessarily predictable.

This is not a guide. This is just so I remember how to get back where I started, in case I wipe this thing. =)

Extremely helpful guides that got me here:

• http://imti.co/post/145442415333/raspberry-pi-3-wifi-station-ap
• https://serverfault.com/questions/124774/have-a-service-start-on-startup-with-ubuntu
• https://raspberrypi.stackexchange.com/questions/63841/rpi-zero-w-as-both-wifi-client-and-access-point

In my particular configuration, the Pi was set up with a hostname of altoid. With the avahi tweak, I am now consistently able to access the Pi via altoid.local from machines on the same network (or connected directly, via the AP).

Out of the box, I used the "NOOBS" that comes preloaded, got internet via wifi, and selected to install Raspbian Lite. After that, I installed dnsmasq, and hostapd. Not sure if anything else was required.

/etc/network/interfaces

source-directory /etc/network/interfaces.d

auto lo
auto eth0
auto wlan0
auto uap0

iface lo inet loopback

iface eth0 inet dhcp

allow-hotplug wlan0

iface wlan0 inet dhcp
wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf

iface uap0 inet static
  address 192.168.50.1
  netmask 255.255.255.0
  network 192.168.50.0
  broadcast 192.168.50.255
  gateway 192.168.50.1

/etc/dnsmasq.conf

# Lots of default stuff commented out. 
# Then this... 
interface=lo,uap0
no-dhcp-interface=lo,wlan0
bind-interfaces
server=8.8.8.8
domain-needed
bogus-priv
dhcp-range=192.168.50.50,192.168.50.150,12h

/etc/rc.local

# Print the IP address
_IP=$(hostname -I) || true
if [ "$_IP" ]; then
  printf "My IP address is %s\n" "$_IP"
fi

# I don't think this part even works...?
printf "Sleeping for 5 seconds befor hostapdstart"
sleep 5
hostapdstart >1&

exit 0

/usr/local/bin/hostapdstart

#!/bin/bash
PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
iw dev wlan0 interface add uap0 type __ap
service dnsmasq restart
sysctl net.ipv4.ip_forward=1
iptables -t nat -A POSTROUTING -s 192.168.50.0/24 ! -d 192.168.50.0/24 -j MASQUERADE
ifup uap0
hostapd /etc/hostapd/hostapd.conf

/etc/hostapd/hostapd.conf

interface=uap0
#driver=
# The name for the AP. Can include spaces, like "Inconspicuous Rock".
ssid=your_ap_wifi_network_name
#country_code=US
hw_mode=g
channel=11
macaddr_acl=0
auth_algs=1
ignore_broadcast_ssid=0
# Comment out the wpa* group below if you 
# want to run an open network. 
wpa=2
wpa_passphrase=the_password_for_this_network
wpa_key_mgmt=WPA-PSK
wpa_pairwise=CCMP
wpa_group_rekey=86400
ieee80211n=1
wme_enabled=1

/etc/default/avahi-daemon

# I had to change this from 1 to 0, because avahi 
# wasn't running on start (probably failing early). 
# This was key to be able to access the Pi via 
# its "{hostname}.local" address on the network.
AVAHI_DAEMON_DETECT_LOCAL=0

@Oddnoun I think Jessie? I'll have to fire it up and check. It was whatever was most current (and stable) on June 9th, 2017.

Jessie, for sure! Stretch has made some changes on networking, so establishing a static IP is somewhat different

is this configuration still working on Raspberry Pi 3 model B? I have struggled for this for a weeks until now

@pvanh80 I've never owned or used a Pi 3, so I don't know. Sorry.

i used the script by @lukicdarkoo at https://github.com/lukicdarkoo/rpi-wifi with minor modifications. It worked perfectly with Raspbian Buster (Dec 2019).

Change the script as below (per comments by @david712 on Mar 6 2019 at https://gist.github.com/lukicdarkoo/6b92d182d37d0a10400060d8344f86e4):

---

wpa=2PASSPHRASE
to
wpa=2

next, insert #!/bin/bash as below

# Populate `/bin/start_wifi.sh
sudo bash -c 'cat > /bin/rpi-wifi.sh' << EOF
#!/bin/bash
echo 'Starting Wifi AP and client...'