I have a larger project in mind that will put a few different computer systems into my car, but one of the critical pieces to that system is the ability to get information quickly from the internet. I thought about mounting a laptop with a bluetooth adapter into the car and tethering it to my phone, but I need my phone for calls and I don’t want to have to choose between the two. So I came up with this little hack that allows me to pretty much permanently mount a wifi router and 3G data card into my car. I flick a switch and it dials up the internet and then shares out that connection via wifi to any device that wants it. The easiest, and cheapest, way I found to do this, with the parts I had available, was to buy the smallest 3G wifi router (a Zoom model that had the added benefit of having a backup battery) I could find and an adapter to turn my expresscard 3G adapter into a USB one. SIIG makes the adapter and it works without any drivers, but only on ExpressCards that are USB based.
Here are all of the parts and pieces layed out. On the left is the router. The cable hanging out of the side is the one that I grafted onto the PCB, but I forgot to take a before shot. The metal rectangle in the middle is the SIIG USB to ExpressCard adapter. I’m actually glad it’s made of metal because my 3G card generates a fair amount of heat. On the right is the 3G card in question. I also carved up a USB cable to make it shorter and allow me to shrink the total package size down.
The USB connection for the router is on it’s right hand side. Unfortunately, I couldn’t find any right angle USB connectors nearby and a 2 inch adapter sticking out of the side made this unit much more cumbersome to mount up. Out comes the solder iron! I took a small, round file and made a hole right above the USB connector just large enough to run my cable through. I then used some heatshrink on the cable to make it a little thicker so when the case was back together, it acts like a hold down to keep the wire from being pulled off the PCB. I used a busted cable and my multimeter to make sure I was connecting the wires up correctly and had to get out the lighted magnifying glass to get everything connected.
Here are all of the parts mounted and cabled together. The SIIG adapter is held to the back of the router using velcro tape. The cable is cut to fit so it doesn’t stand out too far on the side of the router and the USB plug that fits into the adapter has been modified also to support a 90 degree bend. The vent on the router is unblocked and the SIIG adapter does a fairly good job of pulling away the heat from the 3G card.
And here is the unit mounted inside of my car. I have a Ford Freestyle and this is the front seat center console. The little pocket is actually the tissue holder and it’s cut was perfect for this unit. I have access to the power switch very easily at the top right by the 3G card and the vents can get air with little effort. Not pictured is a power wire that I ran from the 12v outlet that is inside of the console up to the unit itself. It can run on it’s battery for up to 4 hours if I need.
This was a very simple little hack, but I think it will have a large pay back when the other systems start to come online. Enjoy!
