Saturn joypad micro-controller?

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tcancian
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Saturn joypad micro-controller?

Post by tcancian » 24 Sep 2014, 23:11

Hi guys, I've got a question to ask and this forum is quite probably the best of all places to do so. I have two Dreamcasts, a Sega VS cable and two Twin Sticks, one for the Saturn and another for the Dreamcast. I've noticed the DC doesn't have enough digital buttons for the Twin Sticks (UDLR+UDLR+T1+T2+D1+D2+START, 13 inputs) so if there's any expert on this issue:

How does the Dreamcast controller micro-controller IC handles the Twin Sticks? Is it a different micro-controller than the one in the average Dreamcast controller?
I've opened up the controllers and TwinSticks and the micro-controller is numbered differently, but it's apparently the same model, of course there's the possibility it's programmed differently or the board has additional circuitry to it.

I'm building a Twin Stick myself, using parts from upright cabinets of the game, and I want to use it on the second Dreamcast and possibly as a XBOX 360 controller, can I use an average first model SS controller for padhacking or is the micro-controller on the Saturn different from the stock joypad? My theory is that I could then use the SS to DC controller converter to get it working on VOOT. The SS has enough digital buttons for the TwinStick so I take the SS version of the TwinStick uses a standard controller board and IC.

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MentholMoose
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Re: Saturn joypad micro-controller?

Post by MentholMoose » 25 Sep 2014, 01:58

tcancian wrote:I've noticed the DC doesn't have enough digital buttons for the Twin Sticks (UDLR+UDLR+T1+T2+D1+D2+START, 13 inputs)
14... you forgot the PAUSE button. 8-)
tcancian wrote:How does the Dreamcast controller micro-controller IC handles the Twin Sticks? Is it a different micro-controller than the one in the average Dreamcast controller?
I've opened up the controllers and TwinSticks and the micro-controller is numbered differently, but it's apparently the same model, of course there's the possibility it's programmed differently or the board has additional circuitry to it.
I'm not sure how it works. The IC may be programmed slightly differently, or there may be some kind of jumpers or something to change how it operates.
tcancian wrote:I'm building a Twin Stick myself, using parts from upright cabinets of the game, and I want to use it on the second Dreamcast and possibly as a XBOX 360 controller, can I use an average first model SS controller for padhacking or is the micro-controller on the Saturn different from the stock joypad?
I don't know, but I think I have everything necessary to test it. If I can find everything I will try it out and report the result.
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twistedsymphony
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Re: Saturn joypad micro-controller?

Post by twistedsymphony » 25 Sep 2014, 05:43

tcancian wrote:How does the Dreamcast controller micro-controller IC handles the Twin Sticks? Is it a different micro-controller than the one in the average Dreamcast controller?
I've opened up the controllers and TwinSticks and the micro-controller is numbered differently, but it's apparently the same model, of course there's the possibility it's programmed differently or the board has additional circuitry to it.
You're assuming that your Dreamcast "sees" the Twin Stick as a normal controller, Like most modern non-standard 1st party controllers that's not the case. Despite the fact that the normal Dreamcast controller only has a limited number of buttons doesn't mean that other controllers can't have more. When you plug your Twin Stick into the Dreamcast it tells it that it's a Twin Stick and the Dreamcast knows to expect all of the Twin Stick style inputs...

Consider the Keyboard controller in Rockband 3, it has 35+ buttons, most of them analog which is way more than a normal Xbox 360 or PS3 controller. but that's because the console works like a PC and has, essentially "drivers" that can interpret different kinds of controllers differently. The N64, Dreamcast and newer consoles use a modified USB protocol for the controllers. However, older stuff like the Saturn works differently and is a bit more limited, but still able to support multiple controller designs with different numbers of buttons.
tcancian wrote:I want to use it on the second Dreamcast and possibly as a XBOX 360 controller, can I use an average first model SS controller for padhacking or is the micro-controller on the Saturn different from the stock joypad? My theory is that I could then use the SS to DC controller converter to get it working on VOOT. The SS has enough digital buttons for the TwinStick so I take the SS version of the TwinStick uses a standard controller board and IC.
The Saturn Twin stick does indeed get registered as a normal controller, it uses the same IC and here is the mapping: http://gamesx.com/wiki/doku.php?id=cont ... ton_layout

I'm dubious that you'd be able to pad-hack a Saturn Twin stick to work on Dreamcast though.... the only way you might be able to make it work is if you could map the analog stick as a 4-way digital input in-game. I don't recall if the DC VOOT allows that granularity though.

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Re: Saturn joypad micro-controller?

Post by tcancian » 25 Sep 2014, 15:35

@MentholMo0se

I'll be waiting then, thanks for the help. :D

@twistedsymphony

I'm aware the IC is programmed differently on the Dreamcast. The theory is to use a Total Control 3 in Twin-Stick Mode to get it working on the Dreamcast. If the driver is different, then I'd have to reprogram the IC or flash it and then use it on a PCB, which is way more work than simply padhacking a model 1, it has common ground and solder points for all the inputs. 8-)

http://www.slagcoin.com/joystick/pcb_di ... agram1.jpg

http://www.amazon.com/Total-Control-Sat ... B008FXKLPI

Wasn't aware of that link, will sure help, thanks!

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Re: Saturn joypad micro-controller?

Post by MentholMoose » 25 Sep 2014, 16:53

tcancian wrote:The theory is to use a Total Control 3 in Twin-Stick Mode to get it working on the Dreamcast.
Based on what twistedsymphony said, using a Total Control 3 should work. If I can find mine I will test it out to confirm.
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twistedsymphony
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Re: Saturn joypad micro-controller?

Post by twistedsymphony » 26 Sep 2014, 06:50

I've never seen a total control 3 before but I agree, there's no reason you shouldn't be able to use that to dual-mod your Saturn Twin Stick.

You wouldn't even have to worry about common ground. you would take the output pins that go to the cable and splice them into the input port on the TC3.. the only problem would be if the TC3 when powered off (unplugged from the Dreamcast) would still cause interference on the Saturn cable... knowing how the Saturn controller protocol works, I don't think it would be much of a problem though.

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