A lot of progress made. I soldered wires to the pickup roller that needs to go on the car. My local train store had the correct roller needed in stock. Thankfully they knew which one it was that was needed (thanks Sommerfelds). I soldered full lengths of wire to the roller. I cut it shorter after I attached the roller to car and I know how much wire I actually need (try not to waste my good wire).
These pickup rollers just snap in place. Very easy task.
After soldering the pickup wires, I did some more soldering for the connections between the MiniCommander Acc and the MP3 board. I only started with the connections I knew I needed. Below you can see the HC1 and HC2 are fully soldered and ready to test. LC1 only has 1 wire soldered from the mini commander to 2 wires from the MP3 board. This is because I plan to use a reed switch to activate these 2 sounds, so I will need to get reed switches in line off the black wire from the mini commander acc. These sounds will trigger one a time, based on which character is at its peak.
Below you can see both boards are connected to track power from my pickup roller. The HC1 and HC2 connectors are plugged into the mini commander. I programmed the mini commander prior to this. Aux 1 played the first sound, Aux 2 played the second sound. A successful first test; I am very happy!
Below I temporarily added a reed switch to the black wire from the LC1 connection. I tested this and was able to hear the 3rd sound when running a magnet past the reed switch. Another successful test.
