Step 10: Prepare the Sensor Plate
Next, we'll prepare the sensor plate. The sensor plate is the big 4" x 4" piece of single-sided copper included in the kit. This plate will be glued to the bottom of the inside of the lamp to detect human touch.
To connect the sensor plate to the PCB, you'll need a short length of wire. I would recommend at least 3-4 inches. Extra doesn't hurt, since everything will be concealed inside the box.
Strip about 1/4" off of each end of the piece of wire, then pick a spot on the copper side of the sensor plate where you'll solder it. You can solder the connection anywhere along the edge of the plate. I put mine in the middle of one side, but a corner would work just fine, too. The sensor plate is a big piece of copper, which makes it hard to heat up a particular spot. If you're using an adjustable iron, it's nice to jack the temperature up a little bit here.
First, just heat up the spot on the board and apply a little solder until you have a solder blob on the board. Then, while keeping the solder blob liquid, stick one of the stripped ends into it, then remove your iron. Once its cooled, you should have a nice joint. Try to use the minimum amount of solder that gives you a good connection - the more low profile this joint, the better.