So I’ve finally reached the moment of truth; it’s time to implement and test my KAOSS Pad touchpad installation design theory.  I’ve actually been putting this off, as I didn’t feel like dealing with any catastrophic failures in design methodology, and the disappointment that comes along with that!  Here is the procedure, in detail, as I know many of you have been waiting…

Here’s what we know:

  1. We will have a KAOSS Pad touch screen that needs to be installed in a guitar body.
  2. The KAOSS Pad control unit will reside on a pedalboard, somehwere away from the guitar.

Here’s what I needed to figure out:

  1. How can I get the touch pad signal, from the guitar, to the floorboard and in a reliable / reasonable manner?

The answer?  CAT5 (network) cable!  You’ve almost certainly seen this at some point in your life.  CAT5 network cable is what you use to plug a desktop computer into a router.  You also use this to plug a router (or cable modem) into a wireless router.  Needless to say, this cable is ubiquitous and very easy / cheap to obtain.  Now let’s take a look at how this cable is constructed.

CAT5 cable comes in just about any length you need, and has a quick snap connector at each end.

  
Cut the cable in half, strip away some of the outer insulation, and you will find four pairs of wires.  The pairs will be a solid color, twisted with a white / striped (with the color of the solid) wire.  This is a pair.  For the purposes of our KAOSS Pad project, we will need a total of six (6) wires to transmit various pieces of data:  four for the touchpad and two for the hold button.
At this point, you could go ahead and just cut off two of the wires, as they won’t be needed.  The methodology I used was to keep all of the solid, color coded, wires and two additional white wires.  The color coded wires will be used to pass the touch pad data, and the white buttons will be used to transmit the hold button data.  Once I had these wires, I stripped just enough of the insulation off of the ends for soldering.  You will need to do this twice:  once for the end that will live in the guitar body, and once for the end that will be connected to the KAOSS Pad base unit.

I really wanted to make this as modular a design as possible.  The reason being is that it would be easier to troubleshoot if I could quickly plug / unplug wires and rearrange the order.  This would also make maintenance much easier.  At first, I scoured the Internet to try and find a suitable Molex connector (I had no idea what a Molex connector was, and so my friend Pat was good enough to help me out with this term) , but none seemed to be small enough for my purposes.  In my travels, I came across a modular wire jumper set, pictured above.  This is perfect for what I am doing, because each 12″ wire has a male end on one side, and a female end on the other.
 It’s solder time!  Like I said, I was a novice at soldering when beginning this project, but have learned a lot, along the way!  To proceed, I took six of the jumper wires, and cut them in half with scissors, and stripped the insulation off the ends, exposing just enough bare wire for soldering.  I put the ends, with the male connectors, aside, and took the female ends.  Matching up the colors of the wire, with the wire inside the CAT5 cable, I made my solder connections.

After soldering each wire, I used a bit of electrical tape to insulate the bare ends / reinforce my solder joint.

This is a shot of one of the CAT5 cable ends, with five of the connections completed (at this point, I forgot the sixth, and went back to connect after I had already taken this picture). I then taped together the group of wires, into a single bundle.  This helps to manage all of the loose ends, as well as provide yet more support to the solder joints.

This is a high-level shot of what the completed wire bundle looks like.  This end will go in the guitar.  Again, you will notice that I only have five of the wires completed at the time of this picture.  The finished product actually has the full complement of six.

Here’s where I get tricky with cardboard! At this point, I needed to connect the other CAT5 end, to the KAOSS Pad base unit.  Due to my soldering in close proximity to the circuit board of the KAOSS Pad, I used some cardboard as a backdrop / safety shield.  Looking at the picture, you will see that I’ve already connected the four touchpad wires, and have the two hold button wires separated.  This is just some housekeeping, as I mentioned earlier, because I wanted to be sure to run the hold button connectivity through the white CAT5 wires.

Here’s the finished wiring harness for the KAOSS Pad base unit.  If you look at the end of the CAT5 cable, you will see a black female to female CAT5 adapter that will allow me to run a long wire between my guitar and the base unit.  This ensures that I can quickly snap in / out the long wire, using the jack style connectors at the end.

Here’s another shot of the completed base unit.  Note, the female / female adapter is not on the CAT5 cable in this picture.   Here’s a link to a product information page, and what this adapter looks like.

Going back to my KAOSS Pad disassembly post from last year, you may remember the tiny, white, components that were used to connect the touch pad screen, to the base unit circuit board.  It is now time to dig those out again!  Note the four connection ends; we will need to connect a single wire to each of these ends, in order to properly connect our touch screen.
Here’s a shot of the completed component connector!  Note, each of the four wires were soldered to the unit, and then taped appropriately, so as to disallow any bridging between the solder connections or bare wires.

This is a closeup of the same connector, fully wired.

Once I completed my soldering, I was ready to wire everything together for my first test!

It is important to pay attention to the way in which you are reassembling your ribbon connector.  You want to ensure that you orient the side with the exposed wiring, towards the side of the connector that makes contact with this.  Now take each of the ends of the jumper wires, and connect them with the ends of the CAT5 cable.  (Note – you will most likely have to do some trial and error at this point, to figure out the correct connection combination.)  Finally, take the RJ45 (connector end) and clip it into the female to female adapter on the KAOSS Pad base unit. 

Time to plug it in and power it up!  Crossing my fingers at this point, I hooked up the power adapter, and turned on the base unit.  The touch pad calibrates to 1.1, on the display screen.
Success!  Touching the corner of the unit, the calibration rises right up to “9”, along with the swipe of my finger!  I have to swap out some of the guitar side connectors to properly enable the Y axis touch sensor, but this is a great start!

Here’s a shot of the LED light in the base unit.  This glows brighter when I touch my finger to the guitar side touch pad.  Aside from some minor adjustments, everything seems to be working properly!  Next up, I need to connect the hold button to the momentary switch, and finalize the installation of the guitar side LED lighting.  Until next time…