Since this tool is meant to be modular and use different pens we need a connector on the wires for the LED. I used a cheap 4 terminal molex connector that can usually be found on cables used for fans in a computer. These cables are cheap and easy to get, so they are perfect.
When I started wiring the controller I did not check the colours of the cables on the connectors so they are a little different, but easy to remember. I connected the black wires, power to yellow, green on green and white on blue, but you can use any combination you like, just remember it for the other pens too. Take care to isolate the soldered areas with shrinking tube to prevent shorts. Picture 25-26
Put a long red and a long green wire through the pen and solder black wires to one side of the pushbutton and white wire to the other side. These kind of pushbuttons have four pins of which two are connected in pairs. You can see which pins are connected by looking at the bottom of the button, there is a gap between the pairs that are connected. If you push the button the two sides are connected to another. The white and one black cable are then pulled through to the end of the pen starting at the opening for the button. The other black cable is pulled through to the front. Make sure you have enough cable at both sides to work with. Picture 27-28
Press fit the button in the opening and prepare the rest of the cables. It is best to solder the cables to the LED so that they are facing towards the middle of the LED because the cables run through the middle of the pen. Solder the red wire to the 5V solder pad, the black wire to the GND solder pad and the green wire to the Din solder pad. If you have more than one LED the Dout solder pad of the first LED is connected to the Din of the next LED and so on. Picture 29-30
Now push the button in the front of the pen and put a drop of glue behind it to hold it in place.
Now you just have to solder the wires at the end of the pen to the other side of connector keeping in mind of the colours. Picture 31-32
It is best to use a drop of glue and some tape to stress release the cables at the end of the pen to prevent them from breaking.
This completes the assembly of the light pen.
I also added models for strap holders that are meant to be glued on the bottom of the controller case so you can strap it on your arm and a clip for the pen that can be glued to the lid for when you don’t need the pen in your hand.
Here are two photos showing how the controller and pen is meant to be used. The second photo shows the second pen I designed that has the LED on its side. Picture 33-34
Finally I want to show you a few examples where I used this tool. The angled pen is great to light the lines of a graffiti and the straight pen is great to draw and write stuff in the air (for which I have only little talent). Picture 35 - 38