Power Switch & Recharger
Since the battery will be encased in the gamepad, and isn't easily accessible to unplug, we need to connect a slide switch to the battery so that we can easily turn off and on the Bluefruit. To do this, we will cut the red positive wire from the lithium battery. The middle pin on the slide switch needs to be soldered to the end of the cut red positive wire of the battery. The next pin on the slide switch will need to be connected and soldered to the Vin pin of the EZ-Key. The black ground wire of the battery can now be connected and soldered to G ground pin on the EZ-Key. We're going to splice a JST extension cable to the circuit so that we can recharge the battery. The red wire of the JST cable will be soldered to the remaining pin on the switch.
The black ground wire of the JST cable needs to be spliced into the black ground wire that's connected to the EZ-Key. The black wires of both the battery and JST cable should now be soldered to the G ground pin of the EZ-Key. Now you can slide the switch and power on the Bluefruit.
In hindsight, you can skip the splicing step and just solder the battery wire to one Ground pin and then solder the charger cable to one of the three pads below the Vin pin labeled "Grounds" - we just love splicing!
Cut the cord!
The cable is not going to be used: we will need to unsolder the connections of the cable from the board. Carefully heat up each connection pin on the PCB and then gently pull out the each of the 7 wires that make up the cord. You can now set aside the cord or recycle it, we don't need it!
The arrangement of the buttons can be seen by following the traces on each of the copper contact points. The PCB has small holes that we will use to wire the buttons from the back. We can thread our wires from the back of the PCB to each trace like in our circuit diagram.
We need to expose a spot of copper on the PCB that will connect to ground. On the center of the D-Pad, we will scratch out a piece of green paint using an X-acto knife.
Measure and cut 12 wires in the appropriate lengths that can be connect to the EZ-Key. Each wire will have a variable length, so it's good to label them out. Use the EZ-Key mapping to reference which button will be assigned to the numbered pin of the EZ-Key. You will need to carefully solder each contact point on the PCB to these wires. Follow our trace reference list below to see which contacts you will need solder and wire. You can follow these traces and see the difference between the positive and common ground.
Trace Reference Sheet
•Up = right trace
•Down = right trace
•Right = top trace
•Left = bottom trace
•L = right trace
•R = left trace
•Select = right trace
•Start = right trace
•Y = left trace
•X = left trace
•B = right trace
•A = bottom right trace
Measure the slide switch and mark a spot on the bottom of the controller with a sharpie. We need to cut out a piece of the plastic from the front and back covers. Use an X-Acto knife to remove pieces, layer by layer until you have a nice tight fit for the switch. Now we can fit the power switch inside the controller.