Difference between revisions of "Hotspot mode"

Revision as of 16:59, 8 October 2016

At the moment this must be considered an advanced topic, but for the adventurous it may be useful to know it is possible to configure the Raspberry Pi to provide it's own Wi-Fi Hotspot.

This is useful to do when there is no Wi-Fi router available (e.g. a rural church), but you still need to link up a tablet or other touchscreen device to Box Of Stops.

Please treat the instructions below as advisory only - Box Of Stops are regrettably unable to support troubleshooting a misconfigured network setup.

For reference, one possibility we are looking at is selling a Micro SD card, with the necessary Raspbian, Box Of Stops and Wi-Fi Hotspot all pre-installed. Please let us know if this would be of interest.

Sequence

We recommend you get Box Of Stops up and running before converting your Raspberry Pi to hotspot mode. At least the download will be easier with a working internet connection.

If you do need to re-enable internet access, one trick you can use is to plug the Pi directly into a router - using an Ethernet cable. The instructions below have only re-configured the Wi-Fi connection, so this works as a back up plan.

Instructions

The instructions for setting up a Wi-Fi Hotspot have been written by those who know a lot more about this at http://elinux.org/RPI-Wireless-Hotspot.

There are a couple of points to make before you work through the instructions though

• If you hit a 404 Not Found error running the sudo apt-get install hostapd udhcpd command in Step 1, please try sudo apt-get update first, to refresh the package list.
• A large part of the instructions are about setting up "IP forwarding" and "NAT". These steps are unhelpful for a standalone Box Of Stops install - if you don't want to enable access to the internet through your hotspot. #Skipping IP Forwarding below describes how to vary the instructions on elinux.org to omit this.

When troubleshooting this topic, it may be helpful to know that the other phrase for this task is setting up a Wireless Access Point.

Connecting

Once the hotspot is enabled on the Raspberry Pi, the remaining steps to connect to Box Of Stops are:

• Associate the tablet/other device with the new Wi-Fi network you have created, using the ssid and wpa_passphrase from the instructions.
• As before, open a browser, and connect to the advertised address (exactly as when you first connected). If in doubt, the IP address you need to connect to is the same as you put into the iface wlan0 inet static section in /etc/network/interfaces in the instructions.

Skipping IP Forwarding

If you are running Box Of Stops truly standalone, with no other router to connect to the internet, then it may be best to skip a couple of the instructions at http://elinux.org/RPI-Wireless-Hotspot. This avoids the connecting device (e.g. a touchscreen tablet) expecting to see an onward connection to the internet, and marking the Wi-Fi connection as incomplete.

The changes to the instructions are:

• When editing /etc/udhcpd.conf in Step 2, comment out the opt dns and opt router lines
• Omit all of Step 4, about setting up NAT and IP forwarding