The process consisted of a modified Gameboy Advance and a modified DDR Pad.
Step 1: Gather Materials
DDR Pad (I bought one @ Gamestop for $15)
Small screw driver
Small stranded wires
Step 2: Modify the DDR Pad
Go to this link for step 2
Step 3: Create a case for the wires
Drill some hole to fit the wire through easy access.
Be sure to NAME the controls for each wire (I used some tape to identify them)
You should have a total of 8 wire strands (2 wires to complete the circuit/pad)
Close the back cover with electrical tape.
Step 4: Modify the Gameboy Advance
Find the primary spots (8 spots) for the directional buttons.
Solder the wire on top of the hardware.
Put back the cover, and snip off excess wire.
Step 5: Make the extension cables
You should again have 8 wires total that connect the gameboy to the ddr pad.
Use some alligator clips to connect these wires together.
Use some wiring clips to make it organized.
Step 6: Connect the corresponding wires to the ddr pad and gameboy.
Make sure you connect them to their corressponding areas. (Right, Right, & Left, Left, etc.)
Insert the game. I used the classic Pacman game.