I downloaded the mapper tool and imported 'MAME_P1+P2.dat'
If I understand this right, I can solder directly to the Nano Pro without needing the breakout board. I can then enable the RJ45 inputs to get additional ports to wire up my 17 inputs.
Two questions I have would be:
In the 'output as' section of mapper.exe, I still see that there is only one d-pad being emulated. Does this matter or is there another layout for 2 player joysticks?
I regret to inform you that the Arduino
Pro Nano uses a 328P processor, not a 32u4 processor -- 328P boards won't work with this firmware.
AFAIK the most common and inexpensive 32u4 board available is the Arduino
Pro Micro which has 17 available input ports -- exactly the number of inputs that you need.
You are right about not needing the daughterboard.
- You can solder the wire from the button directly to the 32u4 board input
or use pin headers on the board and female Dupont pins on the wires if you prefer.
The MAME_P1+P2.dat file was designed for use as a keyboard encoder.
- IIRC if you change "Output Mode" from "Force Keyboard" to "Auto Detect", the computer will see it as a single USB/HID Joypad. (default)
One quirk about the Mapper program is that the "Output System" defaults to "Generic USB/HID Joypad" when you load a .dat file or change something using the "Config" icon.
- If you change the "Output System" to "Generic USB/HID Keyboard", you'll see the MAME P1 and P2 defaults that you can modify to suit your needs.
Since some input ports are not available on the Pro Micro and you'll need to remap some of the ports and keystrokes anyways, you may want to start from Blank.dat and assign the ports and keystrokes to the Button Mapping IDs in the order you want.
- When you get everything configured properly, use the "Export" icon to save your setup as a custom .dat file.
Is there a difference in input lag or Rollover Count when you compare Keyboard vs Joypad emulation?
None that I am aware of.
Scott