Is it possible to analog hack the Dreamcast controller?

[jukingeo]

Hello all,

As the subject says, I am curious if the Dreamcast controller could be hacked to adapt arcade style analog controls (steering wheels, pedals, etc).

Thanx,
Geo

[danny_galaga]

I dont see why not, but it might be more the other way around. Once you measure what resistance the pots in the dreamcast controller are (I assume they are pots) you would measure what resistance the equivalents are in the arcade controllers. If different, you would then buy the correct resistance pots for the arcade controllers. Most if not all arcade controllers use garden variety pots, shouldnt be too hard to replace with different values....

oh, and about four posts down from yours:

http://forum.arcadecontrols.com/index.php?topic=95881.0

 

[jukingeo]

I dont see why not, but it might be more the other way around. Once you measure what resistance the pots in the dreamcast controller are (I assume they are pots) you would measure what resistance the equivalents are in the arcade controllers. If different, you would then buy the correct resistance pots for the arcade controllers. Most if not all arcade controllers use garden variety pots, shouldnt be too hard to replace with different values....

That is what I wanted to know if the Dreamcast is using the standard 5k controls.  I have "heard" a few different things about the controllers, but not knowing what is really true.  One post mentions the Dreamcast analog controls as having 'hall' sensors, and that would be extremely difficult to work with for an arcade application.

oh, and about four posts down from yours:

http://forum.arcadecontrols.com/index.php?topic=95881.0

 

I read that prior to posting and that post mostly has information in regards to setting up the Dreamcast with a VGA video display and very little about hacking controllers.   So while it may be still a WIP, that thread is FAR from "Everything You Need to Know about Mixing the Dreamcast & Arcades".

I know it would probably seem most logical to hack a Dreamcast driving controller, but they seem to be hard to find, and when I do find one it is usually very expensive.

But yeah, the alternative would be to hack the analog controls of a standard controller and adapt them to arcade driving controls (if possible).


Edit:

Yeah, here we go...this is one of the sites that mentions hacking a Dreamcast Controller:

http://pc2jamma.mameworld.info/arc_dc4.html

There is a post here I found the links to the above:

http://forum.arcadecontrols.com/index.php?topic=41419.0

So judging by the above, if that is true that the Dreamcast is using Hall sensors for the analog functions, then I don't see an easy way to hack the controllers so that one could make use of the analog controls.

Thanx,

Geo

[Hoopz]

http://forum.arcadecontrols.com/index.php?topic=72278.msg744790#msg744790

Check out HarumaN's response.  He is the king of controller hacking so perhaps he'll chime in.

[northerngames]

the official controllers use hall effect sensor's.

They can be straight wired to work as digital.

some third party controllers use regular pots over the offical stock hall effect sensor's.

they still use resistence to measure movement so if they are desoldered and matched up with the correct valued pots it can still happen.

they also make hall effect joy's but not at your usuall arcade site's there used for high tech camera controls and what not but they are out there but very expensive if you want an actual hall effect joystick.

me I had a toggle switch to flip between D-pad and thumb stick signals but they both were set to work as digital but all games could be played and the DC really did not use the actual analog sensitivity/function except on a handfull of games so getting true analog is not really needed for the most part.

[NickG]

the DC really did not use the actual analog sensitivity/function except on a handfull of games so getting true analog is not really needed for the most part.

JUST QFT.  I looked into hacking the anlalog directions on the Dreamcast pad before.  Somewhere in circuit between the main IC and the hall effect sensors the signal is just 0-5 volts.  I have successfully tested an official Dreamcast controller with a Ultimarc 360 in it's 0-5 volts output mode (I've forgotten by now which this modes name.)  So, yes it is of course possible.  (the triggers are also 0-5v or 0-2.5v somewhere on the pcb  - I cannot remember now...)  I have since lost interest because now NullDC has Analog via PURUPURU plugin.

[jukingeo]

the official controllers use hall effect sensor's.

They can be straight wired to work as digital.

some third party controllers use regular pots over the offical stock hall effect sensor's.

they still use resistence to measure movement so if they are desoldered and matched up with the correct valued pots it can still happen.

they also make hall effect joy's but not at your usuall arcade site's there used for high tech camera controls and what not but they are out there but very expensive if you want an actual hall effect joystick.

me I had a toggle switch to flip between D-pad and thumb stick signals but they both were set to work as digital but all games could be played and the DC really did not use the actual analog sensitivity/function except on a handfull of games so getting true analog is not really needed for the most part.

Yes, I just have seen some posts on converting the Dreamcast controller Hall sensors to simple digital on/off controls and that might work for fighting games (which I don't care for), but I am mostly interested in the Dreamcast for the driving games.  While I am not a hard core fan of these games either, it does seem that I do take an interest in 18 Wheeler, Hydro Thunder, and a couple of other titles.   Since I can get a Dreamcast for around $25 and the games for around $5, it MIGHT be worth the investment, but I most certainly would like to hack the controls to get a more 'real' arcade feel out of them.   Naturally I would believe that these types of games would use the analog function of the controller.

JUST QFT.  I looked into hacking the anlalog directions on the Dreamcast pad before.  Somewhere in circuit between the main IC and the hall effect sensors the signal is just 0-5 volts.  I have successfully tested an official Dreamcast controller with a Ultimarc 360 in it's 0-5 volts output mode (I've forgotten by now which this modes name.)  So, yes it is of course possible.  (the triggers are also 0-5v or 0-2.5v somewhere on the pcb  - I cannot remember now...)  I have since lost interest because now NullDC has Analog via PURUPURU plugin.

Ok, if it would work with a 0-5v stick, so then it would be possible to create a voltage divider across a standard 5k pot with +5v on the hot side and the other side grounded (the control being the wiper of course)?   If so that would be a big plus.

Thanx,

Geo

[NickG]

yes that works, I tested it that way before I tried my U360.  IIRC, I actually used the 5V and ground already present in the controller's wiring or on the PCB somewhere.  I still have the controller in a box and maybe some photos somewhere of the test points I had soldered my kynar wires on my photobucket.  I will try to link them later if I find them/remember.

[Beley]

Ok, if it would work with a 0-5v stick, so then it would be possible to create a voltage divider across a standard 5k pot with +5v on the hot side and the other side grounded (the control being the wiper of course)?   If so that would be a big plus.

The one problem with this is a typical arcade style joystick only have about 60 degrees of movement on a give axis, whereas the pot inside the joystick usually has 270 degrees, meaning that your voltage will only go from ~2v to 3v.  having said that you can get pots with shorter throws or "S" curve pots.

[NickG]

here are the 0-5v points I used for the 360 test.  (succcessfully tested with MDK2 by spinning the view slow/fast)

[jukingeo]

here are the 0-5v points I used for the 360 test.  (succcessfully tested with MDK2 by spinning the view slow/fast)

Hello All,

I know it has been a while since I last posted in this thread,  but I have been on the fence about going with a real Dreamcast v.s. emulation via NullDC.

For me the biggest con with using actual hardware is the need to swap out discs per game.  Along with that also comes the concern with how the CD-Rom drive will hold up over time.

On the flip side, using Null DC I don't see a direct solution for analog support.  As it is, I am mostly interested in the Dreamcast for making a driving cabinet and it is the consistency of the control setup along with the arcade accuracy that made me interested in the Dreamcast in the first place.

Going the emulation route, I found out that I would need a relatively new machine (perhaps an i3 processor) with a very good video card.   This would cost considerably more than using actual hardware, but I wouldn't need to swap discs nor worry about hardware failure.  But it did get me to wondering how analog control is set up in NullDC.

Going back to using original hardware and hacking a gamepad, I reread this thread and saw how you could up analog controls to the 0-5v input...this is where I left off in the discussion.

NickG,

Thank you for sending that picture, it will come in handy for (or if) the time comes to hack an original Dreamcast controller.  However, in the picture you show only the X-Y 5v access points.  Where are the 5v access points for the L & R analog triggers?

Thank You,

Geo

[northerngames]

http://www.google.com/search?hl=en&q=dreamcast+steering+wheel&bav=on.2,or.r_gc.r_pw.&wrapid=tlif130612711601510&um=1&ie=UTF-8&tbm=isch&source=og&sa=N&tab=wi&biw=852&bih=567

have you looked into just getting a pre-fabbed wheel setup & pulling the guts and soldering them into a real arcade setup?

[NickG]

It has been a while since I have looked at that but I seem to recall that you just can just solder to the pad on the controller-IC side (the other side than that of the digital hack) of the same transistors* that one would use to perform a discrete l/r trigger hack.  These are gonna be a 0-2.5v, IIRC, but you can just check that with your meter, anyway with the triggers in place, and squeezing down on them, while your meter is on the transistors.*
should be fairly simple to trace back the trace from there to near the main-IC if necessary, but I think one of their testpoints/vias is on the backside of the pcb at that point.
*memory is a bit fuzzy.

I am going emulated, now, at least for 1-2 player games which can be played as arcade games.  Sticking with original controls for all the rest unless I build a dedicated setup.  Fro the analogue controllers you need to use the plugin named, "purupuru" or similar.

[abzman2000]

I just thought I'd chime in, although it looks like I may be a little late.  You guys do know you can just use a pot as a voltage divider to get that 0-2.5v or 0-5v signal right? if you hook up 5v to one side of the pot, and ground to the other then the wiper (center pin) will output a value between 0 and 5v dependant on the position of the pot. 

[jukingeo]

have you looked into just getting a pre-fabbed wheel setup & pulling the guts and soldering them into a real arcade setup?

Sure, but cost and availability of a regular Dreamcast controller v.s. a 'stock' wheel is greater.  Meaning I can buy actual Dreamcast controllers for very cheap locally or even on Amazon.  Whereas it is a bit harder to find a stock Dreamcast wheel.   Also since I want to use an arcade control panel, why bother with a full stock wheel setup if a standard controller could be hacked.

I just thought I'd chime in, although it looks like I may be a little late.  You guys do know you can just use a pot as a voltage divider to get that 0-2.5v or 0-5v signal right? if you hook up 5v to one side of the pot, and ground to the other then the wiper (center pin) will output a value between 0 and 5v dependant on the position of the pot. 

Yes, this part I know.  However, what I don't know is the exact locations of where to inject the wiper outputs on the controller PCB.  NickG pointed out the locations of the X & Y inputs of the analog stick above, but what about the points for the left and right triggers?

It has been a while since I have looked at that but I seem to recall that you just can just solder to the pad on the controller-IC side (the other side than that of the digital hack) of the same transistors* that one would use to perform a discrete l/r trigger hack.  These are gonna be a 0-2.5v, IIRC, but you can just check that with your meter, anyway with the triggers in place, and squeezing down on them, while your meter is on the transistors.*
should be fairly simple to trace back the trace from there to near the main-IC if necessary, but I think one of their testpoints/vias is on the backside of the pcb at that point.
*memory is a bit fuzzy.

Hello NickG.   Thanx for chiming back in.  The last time we discussed this, you provided a picture of the Dreamcast controller PCB and pointed out the two X-Y points.   Could you also identify the exact L/R trigger points as well?  Better yet, just post a picture showing all 4 analog points on the full PCB?

I am going emulated, now, at least for 1-2 player games which can be played as arcade games.  Sticking with original controls for all the rest unless I build a dedicated setup.  Fro the analogue controllers you need to use the plugin named, "purupuru" or similar.

100 questions coming...

What's a purupuru?  Where do you get it?  How do you set it up?

Thanx,

Geo