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Help with Gamecon GPIO Input



  • Hi! I've built my own joystick yokes with switches for a track-driven (tank-like) game and would like to wire the switches directly to the RPIE 3 A+ GPIO pins.

    I've installed the gamecon_gpio_rpi module. This only really talks about different controllers from manufacturers, not home built stuff.

    Here is the "TAB" key layout from MAME2003 which should help.

    Thanks for any help you can offer. I'm using a Freescale KL25Z currently to translate the switches to USB keystrokes now. I'd also like to add a start game switch that automatically drops a coin first. I don't know what "RetroPad1" is, for example.

    Key Mapping MAME.jpg


  • Global Moderator

    @MaMikee said in Help with Gamecon GPIO Input:

    I've installed the gamecon_gpio_rpi module. This only really talks about different controllers from manufacturers, not home built stuff.

    The gamecon driver has a few operating schemas, including custom mappings - did you look at the documentation ?

    I don't know what "RetroPad1" is, for example.

    Since you're running with a Libretro Core (lr-mame2003 possibly), that's the RetroPad virtual input device, specific to RetroArch - see here for an explanation on what and how the RetroPad works.



  • I'm savvy with pinball but not so much with home video game stuff so thanks for your patience.

    I've read all the doc I could find. A lot seems to apply to the old 26 pin GPIO connector.

    I am using mame2003 for this.

    Since I installed the gamecon lib the machine has become unusable, presumably because some of the inputs are being triggered by noise. Not sure which inputs I'll have to add PU resistors to. Does anyone know if the library activates the built-in pullups? And which inputs are set to active?

    I'm learning about this stuff all the time and that is good.


  • Global Moderator

    @MaMikee said in Help with Gamecon GPIO Input:

    I've read all the doc I could find. A lot seems to apply to the old 26 pin GPIO connector.

    While the schematics are from the RPI1 era, the driver is supported for the newer 40 pin GPIOS.

    Since I installed the gamecon lib the machine has become unusable, presumably because some of the inputs are being triggered by noise.

    You can remove the driver if that's not working as you expected.

    What's your emulation target - arcade only or also other systems ? There's also mkarcadejoystick which has the same concept, but has a more general approach.



  • @mitu said in Help with Gamecon GPIO Input:

    What's your emulation target - arcade only or also other systems ? There's also mkarcadejoystick which has the same concept, but has a more general approach.

    Since a tank interface is pretty unique the target will be just for this interface. RPIE 3 or later with a 4x3 screen

    Left forward
    Left back
    Right forward
    Right back
    Fire
    Start 1 player (with drop coin and pause if possible - make it simple for the user, freeplay)


  • Global Moderator

    What's the game you're trying to run/emulate ? Tank controls are not so universally used, so I assume the emulator would let you re-map this controls directly - to actual inputs - or to a standard (virtual) RetroPad button/input.



  • Atari's 1980 "Battlezone" from the bzone2 ROMs


  • Global Moderator

    Take a look at

    demonstrating how to map 2 4way joysticks to tank controls - including the Atari Battle zone. IMHO as long as you simulate 2 joysticks, you'll be able to map them in MAME to the tank controls.



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