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Martoni / GbHdmi

HDMI interface for GameBoy DMG
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How to connect the Game Boy controller pins #2

Closed kiwanowski closed 2 years ago

kiwanowski commented 2 years ago

in the gbhdmi.cst file you have:

IO_LOC "gbpad_a" 16; IO_LOC "gbpad_b" 13; IO_LOC "gbpad_select" 17; IO_LOC "gbpad_start" 18; IO_LOC "gbpad_right" 19; IO_LOC "gbpad_left" 20; IO_LOC "gbpad_up" 21; IO_LOC "gbpad_down" 22;

and on the game boy you have pins - P10, P11, P12, P13, P14 and P15

how do you connect those?

Martoni commented 2 years ago

I have some electronic problem with this part for the moment. But You can't connect gbpad_x directly to Pxx pin. An electronic wiring with opto-isolator and diodes is required. I'm doing some more test before publishing the schematic

Martoni commented 2 years ago

gbkeypad_wiring_bugged

I have a problem with this wiring. I can't press two buttons on same "line" (B and left, A and right, ...).

If you have some idea to fix it ?

kiwanowski commented 2 years ago

gbkeypad_wiring_bugged

Maybe something like this? The GPIOs would have to be pulled up and go low when the button is pressed

kiwanowski commented 2 years ago

gbkeypad_wiring_bugged

Another idea

Martoni commented 2 years ago

Yes I tryied with this last schematic with a shottky diode RSX101M-30. But button remain "exclusive" with it. Maybe my wiring hack is bad, or wrong diode.

Martoni commented 2 years ago

I think the LTV-247 is not strong enough to maintain two buttons pressed together. I will try with lighter resistor (47 Ohms instead of 4.7k) then with a dartlington opto-isolator.

kiwanowski commented 2 years ago

Cant you just implement the optoisolator logic inside the tang nano? Examples: https://github.com/andy-west/consolized-game-boy/blob/main/src/nes-controller-gb/nes-controller-gb.c https://gist.github.com/uXeBoy/5e9ec52823b7d73a187370573bdbda1b

Martoni commented 2 years ago

Thanks @kiwanowski, I hadn't found out how the keypad works at the time I made this electronic board. I'll try it and patch my circuit.

Martoni commented 2 years ago

@kiwanowski it's works \o/ with commit https://github.com/Martoni/GbHdmi/commit/5cbc4296c20e8f9961657b98b5afe207238ce324

I «drived» P14 and P15 with 47k pull-up resistor (on 1.8V) and drived P10,11,12,13 directly with 5V buffers.

I will modify my kicad schematics and publish it.

kiwanowski commented 2 years ago

Do you have a pdf schematic of the board to share?

Martoni commented 2 years ago

Do you have a pdf schematic of the board to share?

I'm upgrading new schematics version.

But I tested modification with this schematics modifications :

gbhdmi_hack

kiwanowski commented 2 years ago

Thanks