Here’s a little project I actually did some months ago. I hope it inspires a wave of (legal) guerilla hotspot activity. Milk your wifi and bring affordable Internet to a hotel or cafe near you!
Some people have discussed tapping a USB connection for 5v DC. You can also tap a PS/2 keyboard port (if you have one) for 5v without any additional circuitry. The tap I have wasn’t entirely built by me. It was provided by Logitech to supply power to an old webcam. It can connect to both large and small keyboard connectors, and has an extra side wire where the 5v is split off. I stripped the wires and determined which one was + and – by trial and error. The power connector was cut off from some other transformer. I keep lots of small parts like this.
Here is a photo of a PS/2 connector showing which pins you need to tap:
Here is a photo of my La Fonera resting comfortably with it’s new power connector:
Here is La Fonera behind my trusty old laptop, showing that it is indeed working with the laptop keyboard port as power source, and Ethernet jack as Internet source. Sorry it is underexposed, I wanted you to see the glowing LEDs better. I hope you can see, on La Fonera I have power, Internet and WLAN lights all working, and also the link light on my Ethernet jack. Click photo for larger version:
Finally, it was necessary to enable Internet Connection Sharing (ICS), which is included with most versions of Windows. Alternatives and equivalents exist for every major operating system.
My Internet source is my WPA encrypted Linksys router, and I need to share it with my La Fonera, which is connected to the Ethernet jack. Sharing can only be enabled for one network device, and it is automatically assumed that every other network device will be bound to it. Note that ICS does not appear as a menu choice unless your computer has at least two enabled networking devices. Under Network Connections, I select the wifi adapter, NOT the Ethernet jack, and enable ICS on the Advanced tab:
Now, what can you use this for? Perhaps you are unable to run an Ethernet cable out to your La Fonera, but are within range of another hotspot which you are permitted to access. Perhaps you would like to provide a Fon hotspot for a group of people, and have a cellular data, WiMax or other wireless modem device to supply the Internet connection. It may even be possible to pay for a connection to an expensive commercial hotspot, and spend a day making some positive income by reselling it at Fon’s cheaper rates to everyone else there. You could even use an existing Fon hotspot; pay for a Fon daily pass, and then resell another Bill’s wifi for your own profit (please get his permission first)!
This arrangement should work to supply at least a basic Internet connection, for WWW and email. It is probably a poor substitute at best, for true WDS meshing, to extend the range of your wifi. Performance will certainly suffer due to latency and the effects of performing NAT behind another NAT. Lastly, ICS does not always recognise unusual network devices, especially ones which require special drivers. Some ISPs may require such drivers to help enforce their one-computer-per-customer Terms of Service.
I’d love to hear from anyone who has milked another wifi hotspot like this.