Have your ever imagine that is it possible to set up your own access point?
Don't worry. Yes, we can set up our own adorable WiFi router using Raspberry Pi.
Here in this experiment, I'm trying my hand to set up Pi as an access point more advanced than using it as a client. This tutorial will help to make it so the Pi broadcasts a WiFi service and then routes internet traffic to an Ethernet cable. Since it's all Linux we can go in and update or configure it however we like.
Things Required:
1. Raspberry Pi with Raspbian OS
2. Ethernet Cable
3. WiFi Adapter
First make sure to have Raspbian installed in Pi.
Then connect to Pi using putty.
Shutdown the Pi and plug in the WiFi module when the Pi is off.
Software Installation:
Make sure the Ethernet connection is up to have internet access to the Pi.
Install software onto Pi that will act as host access point.
sudo apt-get update
sudo apt-get install hostapd isc-dhcp-server
Setup DHCP Server
Next we will edit /etc/dhcp/dhcpd.conf, a file that sets up our DHCP server - this allows wifi connections to automatically get IP addresses, DNS, etc.
Run this command to edit the file
sudo nano /etc/dhcp/dhcpd.conf
Comment the below lines by adding # at the beginning
option domain-name "example.org";
option domain-name-servers ns1.example.org, ns2.example.org;
uncomment the line below by removing #
#authoritative;
Then scroll down to the bottom and add the following lines
subnet 192.168.42.0 netmask 255.255.255.0 {
range 192.168.42.10 192.168.42.50;
option broadcast-address 192.168.42.255;
option routers 192.168.42.1;
default-lease-time 600;
max-lease-time 7200;
option domain-name "local";
option domain-name-servers 8.8.8.8, 8.8.4.4;
}
Save the file by typing in
Control-X then
Y then return
Run
sudo nano /etc/default/isc-dhcp-server
and scroll down to
INTERFACES="" and update it to say
INTERFACES="wlan0"
close and save the file
Set up wlan0 for static IP:
If you happen to have wlan0 active because you set it up, run
sudo ifdown wlan0
Next we will set up the wlan0 connection to be static and incoming. Run
sudo nano /etc/network/interfaces to edit the file
Find the line
auto wlan0 and comment all the lines from it by adding # at the beginning of each line.
Basically, just remove any old
wlan0 configuration settings, we'll be changing them up.
Add the lines
iface wlan0 inet static
address 192.168.42.1
netmask 255.255.255.0
Save the file (Control-X Y
)
Assign a static IP address to the wifi adapter by running
sudo ifconfig wlan0 192.168.42.1
Configure Access Point
Now we can configure the access point details. We will set up a password-protected network so only people with the password can connect.
Create a new file by running
sudo nano /etc/hostapd/hostapd.conf
Paste the following in, you can change the text after
ssid= to another name, that will be the network broadcast name. The password can be changed with the text after
wpa_passphrase=
interface=wlan0
driver=rtl871xdrv
ssid=Pi_AP
hw_mode=g
channel=6
macaddr_acl=0
auth_algs=1
ignore_broadcast_ssid=0
wpa=2
wpa_passphrase=Raspberry
wpa_key_mgmt=WPA-PSK
wpa_pairwise=TKIP
rsn_pairwise=CCMP
Now we will tell the Pi where to find this configuration file. Run
sudo nano /etc/default/hostapd
Find the line
#DAEMON_CONF="" and edit it so it says
DAEMON_CONF="/etc/hostapd/hostapd.conf"
Then save the file
Configure Network Address Translation
Setting up NAT will allow multiple clients to connect to the WiFi and have all the data 'tunneled' through the single Ethernet IP. (But you should do it even if only one client is going to connect)
Run
sudo nano /etc/sysctl.conf
Scroll to the bottom and add
net.ipv4.ip_forward=1
on a new line. Save the file. This will start IP forwarding on boot up
Also run
sudo sh -c "echo 1 > /proc/sys/net/ipv4/ip_forward"
to activate it immediately
Run the following commands to create the network translation between the ethernet port
eth0 and the wifi port
wlan0
sudo iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
sudo iptables -A FORWARD -i eth0 -o wlan0 -m state --state RELATED,ESTABLISHED -j ACCEPT
sudo iptables -A FORWARD -i wlan0 -o eth0 -j ACCEPT
You can check to see whats in the tables with
sudo iptables -t nat -S
sudo iptables -S
To make this happen on reboot (so you don't have to type it every time) run
sudo sh -c "iptables-save > /etc/iptables.ipv4.nat"
run
sudo nano /etc/network/interfaces and add
up iptables-restore < /etc/iptables.ipv4.nat
to the very end
Update hostapd
Before we can run the access point software, we have to update it to a version that supports the WiFi adapter.
First get the new version by typing in
wget http://adafruit-download.s3.amazonaws.com/adafruit_hostapd_14128.zip
to download the new version (check the next section for how to compile your own updated hostapd) then
unzip adafruit_hostapd_14128.zip
to uncompress it. Move the old version out of the way with
sudo mv /usr/sbin/hostapd /usr/sbin/hostapd.ORIG
And move the new version back with
sudo mv hostapd /usr/sbin
set it up so its valid to run with
sudo chmod 755 /usr/sbin/hostapd
First test!
Finally we can test the access point host! Run
sudo /usr/sbin/hostapd /etc/hostapd/hostapd.conf
To manually run hostapd with our configuration file. You should see it set up and use
wlan0 then you can check with another wifi computer that you see your SSID show up. If so, you have successfully set up the access point.
Username : Jyothi_Pi_AP
Password: SaiJyothi
You can try connecting and disconnecting from the Pi_AP with the password you set before (probably Raspberry if you copied our hostapd config), debug text will display on the Pi console but you won't be able to connect through to the Ethernet connection yet.
Cancel the test by typing Control-C in the Pi console to get back to the Pi command line
Second Test!
Also we can test simple HTTP get webclient test using NodeMCU using the available access point.
Username : Jyothi_Pi_AP
Password: SaiJyothi
Using the Arduino programming we can establish this connection. Run below code in Arduino to test.
Code:https://github.com/jyothi-lanka/IoT/commit/48c6e008dd960fc2719650671c64c42e68305a79
Finishing up!
OK now that we know it works, time to set it up as a 'daemon' - a program that will start when the Pi boots.
Run the following commands
sudo service hostapd start
sudo service isc-dhcp-server start
you can always check the status of the host AP server and the DHCP server with
sudo service hostapd status
sudo service isc-dhcp-server status
To start the daemon services. Verify that they both start successfully (no 'failure' or 'errors')
Then to make it so it runs every time on boot
sudo update-rc.d hostapd enable
sudo update-rc.d isc-dhcp-server enable
