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fruit-bat / pico-zxspectrum

ZX Spectrum for Raspberry Pico Pi RP2040
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ps2 keyboard support #12

Closed fruit-bat closed 2 years ago

fruit-bat commented 2 years ago

Some examples of use it:

https://github.com/tvlad1234/pico-ps2Driv https://github.com/lurk101/pico-ps2kbd/blob/master/example.c

shaeon commented 2 years ago

It will be Great! When you add support ps2 I'll use on our board!

fruit-bat commented 2 years ago

I've ordered some ps/2 breakouts so I can have a look at this. It may require some extra circuitry as some keyboards/mice had internal pull up resistors on the open collector outputs which would damage the rp2040 (the pull up would be to 5v). Maybe just a resistor and a zener? I'll have a think.

shaeon commented 2 years ago

I used next adapter on many fpga 3,3v gpio without problems:

https://www.waveshare.com/wiki/VGA_PS2_Board

I contact to waveshare and they told me i need used 3,3v. This scheme it's that i used on my mother board with pi pico :)

fruit-bat commented 2 years ago

Ah, thanks for that. I take it you still power your keyboard at 5v?

I think most PS/2 keyboards do not contain a pull-up to 5v, and when this is the case the Zener diode is redundant (you would know if your keyboard has a pull-up resistor cause it would have most likely broken the GPIO pin on your RP2040/fpga).

Are you intending to use HDMI or VGA for the video? If you let me know your setup I could have a go at a making a build target that matches your circuit.

shaeon commented 2 years ago

Almost all ps2 keyboards that i used work well with 3,3V. I would like setup ps2 keyboard and HDMI output video.

Waveshare ps2+vga adapter usually i set for testing environment.

fruit-bat commented 2 years ago

Parts arrived and successfully receiving key-codes from the keyboard using: https://github.com/lurk101/ps2kbd-lib Need to map PS/2 keys to HID keycodes etc...

fruit-bat commented 2 years ago

There is now basic support for PS/2 keyboards (set 2), with some caveats:

I've uploaded the new HDMI uf2 files containing the new behavior.

Let me know how you get on with it... which may encourage me to finish the code!

fruit-bat commented 2 years ago

Hope you are happy with the PS/2 driver. I'll close this issue but feel free to open new issues if you are having trouble with it.