Small JVS IO board for Arcade Sticks

[buffi]

The backstory here is that I want an arcade stick that I can plug directly into my Exa Arcadia, without a external IO board. Still needs an additional USB cable for power though.
I'm using a Iona USB HID IO board now which is pretty nice, but this is an other option to do it.

Basically, what I wanted is:
- Only P1 controls
- No JVS daisy chaining support
- Need to work for all my JVS equipment
- Compatible with the lower latency JVS' spec that Exa is using for new games
- Compatible with Brook Board wiring cables, so I don't need to make my own cabling.

I have a td-io JVS IO setup for my Naomi, and since that is open source, I made a small scoped down PCB using the tranceiver circuit from there. Since I only care about p1 controls, I removed the shift registers and just wired the inputs to the pico directly, and modifiedthe firmware for this instead.

Turned out like this:

This is the first prototype, and I have some improvements I'd like to make for a v2.

Wont be selling this, but dev is open source and will end up at https://github.com/buffis/smol-jvs-io
Note that since this is a WIP, the project there might not reflect the board seen above

 

[buffi]

Been using this and it works real well.

Made a new ver which should be sized the same as the default pcb in the Hori RAP VX stick, so hopefully I can use it as a drop-in replacement that screws in nicely when it arrives.

Also minor silkscreen fixes, and replaced the left connector types to be compatible with "Brooks 4-Pin Button Harness" cables

Sense now also uses a resistor (like Open JVS) intead of 4 diodes, since that makes BOM simpler.

Assuming this works, it'll be final ver

 

[ita123]

Does this compatible with sega naomi jvs?

 

[buffi]

Yes

 

[nam9]

Aren’t there cases where the diode model is preferable to the resistor model for sense? Some systems had issues with a resistor alone…

Really cool project nonetheless!

 

[buffi]

Aren’t there cases where the diode model is preferable to the resistor model for sense? Some systems had issues with a resistor alone…

Really cool project nonetheless!

Yes. OpenJVS docs indicate that Triforce doesnt work with resistor solution for sense.

Anything I care about should work fine though.