@sleve_mcdichael
Thanks for pointing out the obvious that was staring right in front of me...

Accomplished what I wanted in a much easier way.

Thanks for the help!

nevermind it works now !

@SKYNET2023 said in Retropi LR-Mame-2016 Won't Recognize Sinden Lightgun P2 Trigger | Everything else works fine:

Built From: Raspberry Pi4 Sinden Lightgun image - BareBones v9

We don't support 3rd party images. Please ask the author of the image for advice or use the RetroPie image from retropie.org.uk/download.

@Folly Thank you so much for doing this. It was very kind of you. Very helpful, informative, and solved my long problem with this game.

@Ashpool Note that if you were looking into more recent MAME vintages to fix emulation issues present in older ones, FBNeo would be a solid alternative and doesn't have the rotation bug.

@dankcushions Yep, that was actually helpful! Thank you!

Here's what I did to make it all work.

Your cheat.7z file has to be in this folder:
/home/pi/RetroPie/BIOS/mame2016/cheat

You can get the cheat file here:
https://github.com/libretro/mame2016-libretro/tree/master/metadata

Load up a game in lr-mame2016 like "Donkey Kong" for example, and then go into options and "Enable Cheats."

Screen Shot 2021-03-02 at 8.00.47 PM.png

You then need to RESTART the game (It does not say restart required in the options, but you have to restart) and then when you load up the game again, press TAB on the keyboard to get to the MAME Menu:

Screen Shot 2021-03-02 at 8.02.10 PM.png

And then you can be just like Billy Mitchell and cheat to your hearts desire! :P
Screen Shot 2021-03-02 at 8.02.43 PM.png

I've tested it in quite a few games as so far so good!

Thanks again for the help!

@YFZdude I’m also looking at the MAME2016.rmp file (I didn’t change anything in here) but it says

input_libretro_device_p1= “5”
input_libretro_device_p2= “1”
input_libretro_device_p3= “1”
input_libretro_device_p4= “1”
input_libretro_device_p5= “1”
input_player1_analog_dpad_mode = “1”
input_player1_btn_select = “-1”
input_player1_btn_up = “-1”

Is this correct considering select is usually an 8? It doesn’t make sense to me why the select and button up are the same?

Glad it's working for you.
I'm still learning some of this but just for reference, I think a "-1" would be the equivalent of saying that button is either disabled or undefined. All regular buttons probably should have a number with no sign (+ or -) associated with them. An analog function usually mentions an axis and those can have a negative sign for one direction and a positive sign for the other direction.

So, what are your results? Did you try running it with some games? Please report...