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Build your own JVS I/O board

twistedsymphony

twistedsymphony

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I was searching for some JVS information online and came across this awesome project. Some guy used a cheap AVR device and built his own cheap JVS I/O board. Seems like this could be quite useful, if tweaked it could potentially serve in place of a Type 3 I/O for those games that require it.

 
i found that a few days ago ordered my parts so i can do so. want a pcb without extrenal duaghter boards. but taht will come later
 
A JVS type IO that fits inside a PC like the pcb in a type X2 would be great. It would make MAME in a veiwlix or Naomi plug-n-play...
 
LOL
Yeah, I've been working with the TeensyJVS code myself for a little while as well- the code needs almost complete rewrite, but at least the framework is solid!

Can't get it to talk correctly on a real arduino however.. I need to work out how the HardwareSerial extensions in teensyduino work.
 
penrhos said:
A JVS type IO that fits inside a PC like the pcb in a type X2 would be great. It would make MAME in a veiwlix or Naomi plug-n-play...
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what you're talking about is a JVS Host emulator, which is not what this does. this is a JVS I/O board it replaces the board that's already in your Vewlix/Net City cab, you'd still need a JVS Host device to plug it into.

This would be great for consolization because you wouldn't need to fit a whole JVS I/O board inside the case.

If you wanted to add a JVS port to a PC so that you can plug JVS I/O boards into it then that's something different altogether. Though the documentation for this would help you build such a device.
 
Or you could use existing devices like the JVS-Pac for host emulation
 
defor said:
Or you could use existing devices like the JVS-Pac for host emulation
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feature wise JVS-PAC is pretty abysmal. it only maps to keyboard keys and is hard coded to the default MAME keyboard layout.

this means only 2 players, only basic joystick controls and really only good support in MAME since the default keyboard layout uses lots of special keys that are un-mappable in other applications.
 
twistedsymphony said:
only good support in MAME since the default keyboard layout uses lots of special keys that are un-mappable in other applications.
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Pretty sure there's a gamepad HID profile that can be used- sorry- I've misplaced mine, and it's been a while, but yeah.

All the same, there's interestingly another project out there too for connecting jvs to pc...
https://github.com/k4roshi/JVSy

I'm not that interested in a jus io for pc, but i'm sick of chaining adapters to get a nice consolized setup, and that's my main interest in teensyjvs.
 
defor said:
twistedsymphony said:
only good support in MAME since the default keyboard layout uses lots of special keys that are un-mappable in other applications.
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Pretty sure there's a gamepad HID profile that can be used- sorry- I've misplaced mine, and it's been a while, but yeah.
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That'd be news to me. I was looking for options for my light gun setup and and when I emailed him about 2 months ago I was told there was no analog support and no alternate profiles.
 
twistedsymphony said:
That'd be news to me. I was looking for options for my light gun setup and and when I emailed him about 2 months ago I was told there was no analog support and no alternate profiles.
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Oh, that part is VERY TRUE that there's no analog in JVSPAC.

I'd watch that project I just linked, or if you want, I can possibly poke around in it myself- what kind of gun IO are you using?
 
defor said:
twistedsymphony said:
That'd be news to me. I was looking for options for my light gun setup and and when I emailed him about 2 months ago I was told there was no analog support and no alternate profiles.
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Oh, that part is VERY TRUE that there's no analog in JVSPAC.
I'd watch that project I just linked, or if you want, I can possibly poke around in it myself- what kind of gun IO are you using?
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It's the OMZ board (aka Sega Type-II IR) that Sega has used on nearly everything since Jurassic Park. I've already got it adapted to PC since the board outputs 5V analog directly and I ended up using a KADE joystick encoder. it's cheap and works extremely well, plus it's got several analog channels if I want to add accelerometers to the guns for "shake" support. I have a whole thread on the project here: Shooting Gallery: Sega Type-II IR on a 108" front projection setup.
 
werejag said:
does daisy chaining two together work?
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that would all depend on if the device was built to support that function of the JVS protocol.

really that's not much to do with software but how the hardware was built... in otherwords.. yes, if you build it right.
 
werejag said:
just add a extra usb socket right?like the reg jvs board
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no,

The JVS spec (From what I can gleam from the translated Documentation), shows that one of the pins has resistors in place on the sense pin, so based on the total voltage across that pin the JVS devices know which node in the chain they are, and the host will know the total number of nodes. this looks like a really simple voltage divider setup.

So in addition to adding another USB socket you'd need to wire up the sense pin on both sockets to handle the voltage divider circuit properly.

The host will then request data from each node one at a time... so the software on the AVR would at least need to know what it's node is, and when to respond and when to wait while another node responds. I would suspect in order to handle the request and respond functionality correctly this was built to function properly, it's also possible that they took the easy way out and just assumed they're node 1 all the time and respond to every request regardless of what node the rest is for, in which case you'd have to modify the AVR code to handle this properly.
 
This is very cool. Anyone get far on replicating this man's work?

Also, I would think that you would need a breakout board if you need 15khz CGA resolution output. That is easy enough I suppose.
 
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