The concept of headless Pi at Jams and in classrooms has always been a subject close to my heart and recently I’ve been trying to go down the route of a Pi that see if it gets an IP address from a DHCP server, if not – it turns itself into a hotspot so that other computers can connect and communicate to it over WiFi.
So sequence should be
1. Check if IP been handed out on WiFi from a DHCP server – if OK End
2. If not, create hotspot for other Pi/clients to use.
The basic software needed is something called hostapd to make the Pi appear as a WiFi access point and dnsmasq so that it can hand out ip addresses to anything connecting to it.
Note: Hopefully this current state will be taken over by @heeedt https://github.com/heeed/hotpi
Working Hotspot (but no automatic changeover) using 8188CUS based adaptors
To get this working you need to connect your Pi to the internet using a LAN cable.
Then copy and paste this into an LX Terminal session
wget http://git.io/wZV8tg -O ipispot.sh
and then type
sudo bash ipispot.sh
You will be asked a series of questions but unless you an advanced geek or the network you are running on is using 10.0.0.xx addresses – just accept the default for each question
The only exceptions to this would be for your country and WiFi channel number
At the end, it will ask to reboot – once done, you should now see a open ClassPi available WiFi connection that you can connect to.
The hotspot does not supply a bridged connection to your LAN and the internet – (it would be an access point if it did that) it is purely designed to let you connect to it from a WiFi laptop or any WiFI enabled device such as as tablet
Please try and give me feedback