MAME coin button sometimes doesn't work

  • Hi guys again. I have an arcade joystick and buttons connected through the GPIO to my raspberry pi 2. Everything works fine except some games in MAME for some reason don't respond to the coin button (wich is suposed to be select) but do respond to the key 5 in a keyboard. It doesn't happen with all the games, only a few of them, but it is quite annoying since it is a bartop and I don't want to have a keyboard connected. Is there any solution for this?

  • Staff
    Global moderator

    Hi, it' a know bug, not corrected yet. The only solution is to have an other button for hotkey....

  • Hello, sorry if I open this topic, but I think it's the same problem that I have.
    But I have it with the coin acceptor. When I insert the physical coin, sometimes the game counts it and sometimes not (it's a bit random). I have noticed that the games to which problems are those that have the multiple counter of the coin (for example in those games with more players like the king of dragons, etc.). Instead the neogeo rom, all have a single counter and the coin mechanism always works.
    Can you confirm that there is still this bug?


  • Banned

    This is not a bug from Recalbox but from your schematics. I have no idea how it is connected. But if you can switch the impulse time, put it to the highest value. If you have 12 V on the coin mecanics and you switch gpio with this to the ground ---> harakiri. So if the interface is not correctly made with some Fet-transistor, better to put a relay between both.

  • Hi, I followed this guide in French:

    The relay power supply is controlled by the coin acceptor. The relay contacts are connected to GPIO GROUND and GPIOxx.

    Regarding the impulse time you were talking about, what do you mean? (maybe the duration?)


  • Banned

    I have some connection like this with possibility to switch for free games. So on the coin acceptors from China you have a switch for the time, that you should put to maximum 100ms long pulse.
    The problem is that in all games there are different modules to control the feature.
    If not pressed long enough, you have no switching.

  • Thank you very much! I solved by setting the timer to "slow speed / long pulse" (now it was set to "medium speed / medium pulse"). Now even all the other non-neogeo mame games that have a multi-counter coin, work properly!

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