It could be useful to have the dash buttons working with the raspberry pi in a place where there is no wifi or internet coverage. The raspberry pi can be setup as a wifi hotspot and the dash buttons configured to join this network. Taking things a bit further, the raspberry pi could be set up to route requests received via the wifi subnet through the cabled network, to the internet router/home network and to the internet.

Yesterday I managed to do this successfully, following this tutorial. Fun times 🙂

The important files for this are:

/etc/network/interfaces
/etc/dhcpcd.conf
/etc/hostapd/hostapd.conf
/etc/default/hostapd
/etc/dnsmasq.conf

recipe of steps I followed

1. sudo apt-get update
2. sudo apt-get install hostapd isc-dhcp-server
3. sudo apt-get install iptables-persistent
4. sudo vi /etc/dhcp/dhcpd.conf
   1. comment the lines
      1. #option domain-name “example.org”;
         #option domain-name-servers ns1.example.org, ns2.example.org;
   2. uncomment the line
      1. authoritative;
   3. Add the following lines at the end
      1. subnet 192.168.43.0 netmask 255.255.255.0 {
         range 192.168.43.10 192.168.43.50;
         option broadcast-address 192.168.43.255;
         option routers 192.168.43.1;
         default-lease-time 600;
         max-lease-time 7200;
         option domain-name “local”;
         option domain-name-servers 8.8.8.8, 8.8.4.4;
         }
5. sudo vi /etc/default/isc-dhcp-server
   1. add wlan0 to the INTERFACES variable
      1. INTERFACES=”wlan0″
6. sudo ifdown wlan0
7. sudo vi /etc/network/interfaces
   1. allow-hotplug wlan0
      iface wlan0 inet static
      address 192.168.43.1
      netmask 255.255.255.0
8. sudo ifconfig wlan0 192.168.43.1
9. sudo vi /etc/hostapd/hostapd.conf
   1. interface=wlan0
      driver=nl80211
      ssid=jarvis
      country_code=US
      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=CCMP
      wpa_group_rekey=86400
      ieee80211n=1
      wme_enabled=1
10. sudo vi /etc/default/hostapd
    1. DAEMON_CONF=”/etc/hostapd/hostapd.conf”
11. sudo vi /etc/sysctl.conf
    1. net.ipv4.ip_forward=1
12. sudo sh -c “echo 1 > /proc/sys/net/ipv4/ip_forward“
13. create NAT rules with iptables
    1. sudo iptables –t nat –A POSTROUTING –o eth0 –j MASQUERADE
    2. sudo iptables –A FORWARD –i eth0 –o wlan0 –m state —state RELATED,ESTABLISHED –j ACCEPT
    3. sudo iptables –A FORWARD –i wlan0 –o eth0 –j ACCEPT
14. sudo sh -c “iptables-save > /etc/iptables/rules.v4”
15. sudo service hostapd start
16. sudo service isc-dhcp-server start
17. sudo service hostapd status
18. sudo service isc-dhcp-server status
19. sudo update-rc.d hostapd enable
20. sudo update-rc.d isc-dhcp-server enable
21. sudo reboot
22. tail -f /var/log/syslog