Quick and dirty connector
From OpenTom
Making a connector is quite easy. All you need is a PCB with suitably arranged traces, plus some things to act as spacers. Pieces of a PCB work great for this. Here are the approximate dimensions of the connector:
In a first step, cut one large piece of copper-covered PCB, about 17mm wide, and at least 20mm long. Then remove material from the long sides with a file, sandpaper, or a knife until it fits tightly. Do this such that either end fits, so that you have a backup if anything goes wrong later.
Next, cut a strip of paper to exactly the same width as the piece of PCB. Insert it into the TomTom and mark the position of the contacts. Use this as a template for the PCB.
Now you can either etch the traces, or grind off the extra copper. Etching is easier. Use a water-proof pen to draw the traces. Make sure the copper does not shine through. Draw the traces from end to end. You may want to arrange things in the middle such that you have larger pads to solder a cable to, but just parallel lines will work fine. Make sure the traces aren't too thin.
Now, get a bit of suitable acid from your neighbourhood electronics shop (there, you can also ask how you should dispose of the used acid), put PCB and acid in a glass you don't like, and wait. Heating the glass a little (but don't make the acid boil ...) will accelerate the process. Use something disposable, e.g. a drinking straw, to stir the acid, and to push the PCB to the side of the glass so that you can check the progress.
When done, wash the PCB with water. Check that the traces connect end to end and that parallel traces don't connect. Dispose of the acid in a suitable way. Whatever you do, avoid contact with metal you didn't mean to throw away anyway.
Meanwhile, you can cut some more pieces to act as spacers. They should be rougly 16mm wide (a loose lateral fit is sufficient). One should be about 2-5mm long, the others can be longer. If your PCBs are 1.5mm thick, you'll need one spacer to go in front of the main PCB, and two to the rear.
Solder wires to contacts 1 (rightmost trace) and 5 and insert the whole assembly. It should now look similar to this:
If everything seems to fit, power the TomTom up, and measure the voltage between the wires. It should be about 3.3V. If you don't get a contact, try adjusting the pressure on the spacers.
You can now proceed by building a level shifter for the Serial Console.
