Since I first started tinkering with the Linksys WRT54G router a couple over a year ago, replacing the stock firmware with OpenWRT, I have been thinking about making something special with it.
The router itself is a great piece of hardware, having a WiFi adapter, and two wired LAN interfaces. OpenWRT allows hackers to do almost anything with the device – there are plenty of mods, such as the dual serial ports, SD card to add storage space, and more.
I tried to look for a GSM/GPRS mod, which would add a module to the router, allowing it to communicate with the outside world using data and SMS – but there was no such thing, at least integrated into the router’s casing. So, the challenge was born, to design a PCB that would hold an SD card reader, a GSM/GPRS engine, and a GPS receiver. What could you do with this device? Here is a short list:
- An autonomous wireless IDS with logging and SMS alerts. This could warn you when a pirate is trying to break into your network via WiFi. It would be completely autonomous, only needing a power source to run.
- Self-contained wardriving box, which can save logs to the SD card, and be controlled via SMS messages. It could also periodically send you a status report to your mobile phone.
- Mobile hotspot – by bridging the GPRS data connection to the WiFi signal in AP mode. Not very fast, but wait until 3G modules come out…
Here is a first picture of the PCB mounted onto the WRT54G. It doesn’t show the mess of cables that covers it, but gives an idea of what it will look like.