Mini-PAC to spinner wiring problem FIXED!

[Paladin]

Before I bug Andy, can anyone here tell me what's wrong with my Mini-PAC to original Atari Tempest spinner wiring?

Current setup:
Mini-PAC power connector J2 has pins 2(5v) and 6(gnd) routed to Atari optic board.
Mini-PAC button connector J1 has pins 33,34 routed to Atari optic board.

Mini-PAC button connector J1 has pins 21(1sw1), 22(1sw2) and 2(gnd) routed to two microswitch buttons.
Mini-PAC connected to PC via 10' USB male to male (shortest I could find) with green USB to PS2 converter.

Symptoms:
No error flashes from Mini-PAC, one flash then steady light.  Both microswitch buttons work fine.
Checking voltages on the Atari optic board with one end of multimeter on the ground pin shows 5 volts on all 3 other pins.

I put the same optic board into a PS2 mouse hack trackball, and it worked fine.  I get 5 volts between the 5v and ground pins, and the voltage on the signal wires swung up and down as I spun the ball - topping out at about 1v.  I plug the trackball into the Mini-PAC and get the same 5v on all pins.

Is it something simple?  Wrong ground wire?  A trace that needs to be cut on the Mini-PAC?  Are the planets misaligned?

Someone help me out so I don't have to bother Andy!

[BobA]

My error in logic.    I was thinking you are PS/2 connected but your adapter has to be on the minipac end to connect the ps/2 to a USB cord.   Is your minipac being recognized as a USB device?  I could not find any info on changing from active hi to active lo like on the optipac so I am not sure how the minipac handles it.

Maybe the easiest would be to email Andy.

[Kremmit]

I don't believe the Mini can be switched from active-hi to active-low, if  remember right, it only supports one- darned if I can remember which.  But if it works with Happ and Betson trackballs, it ought to work with a Tempest optic.

Have you tried using pins 35 and 36 instead of pins 33 and 34?  Those are the trackball inputs.  If your spinner works there, then you know it's either the wiring to the spinner pins, or the MiniPac itself.

[Paladin]

The model I have doesn't have any jumpers on it, so I'm assuming it's all automatic.  I also didn't mention that I bought the board only version, so I'm using an IDE ribbon cable for wiring.  I checked continuity to make sure I'm on pins 33 and 34.

I think the Mini-PAC is supposed to use the same LED codes as the I-PAC, so when I get one flash then steady it should be in USB mode.  For PS2 mode it should flash twice.

Kremmit, I was going to try the trackball inputs just as you suggest if nobody found an obvious flaw in my setup.  If nobody has any other ideas I'll give that a shot later tonight.

[Paladin]

Well, no luck using trackball pins 35 and 36.  I'll email Andy and see what he says.

[Paladin]

Well, a little more searching on the board may have turned up the solution.  I found a thread from Texasmame showing my same problem, and how he made it work:

http://forum.arcadecontrols.com/index.php?topic=59560.0

[Paladin]

Yarg!  Still no luck getting my spinner to work.  I tried adding 1k resistors from signal pins to ground pin as suggested in the other thread, but that makes the Mini-PAC blink an error code of 4 flashes.  I tried two different optic boards with the same result.  I plug in an unmodified optic board and get no error codes, but a solid 5v on both signal pins.

Why is it so hard to get one of the most common optic boards to work with one of the most popular encoder boards?

[BobA]

Texasmame said that his 5V and GND wires were reversed from those in the minipac drawing going to the spinner.  The ultimarc drawings shows 5V as black and Gnd as brown.

To Quote Texasmame
"So, be sure of your wiring (Black = gnd, brown = 5v or, better yet, confirm via a multimeter) and tie down those signals to the ground."

Did you confirm with a multimeter whether your harness is wired as Texasmames was or as the Ultimarc drawing shows?

[Paladin]

I checked online for the Atari optic pinout before wiring it up.  I didn't just trust that the Ultimarc diagram matched my optic board.  My wires are hooked up like the optic board pictured below.  I haven't tried swapping the power and ground, as I'm pretty sure the photo shows the correct position.




 

[BobA]

Do you have a pic of the top side of the board showing the components.  I'd like to draw the circuit and see if I can understand what might be happening for you not to get any voltage transistions.

[Kremmit]

I checked online for the Atari optic pinout before wiring it up.  I didn't just trust that the Ultimarc diagram matched my optic board.  My wires are hooked up like the optic board pictured below.  I haven't tried swapping the power and ground, as I'm pretty sure the photo shows the correct position.
 

I think you and I are reading Tex's comments differently.  I understood him to be saying that the +5 and Ground were reversed on the Ultimarc side, not the Atari side.  But maybe I'm wrong. 

[Kremmit]

OK, I got off my butt and hooked up a duplicate optic board here, it is working fine on an Opti-Wiz.  I can confirm your pin assignments on the optic board.  I don't have a Mini-Pac to test with, at least not yet.  Ordered one yesterday, though.

[Paladin]

Thanks for the help guys!  I'll be out of town for a week, so I won't be able to mess with it for a while.

BobA, I wasn't getting any voltage differences without the resistors - just a solid 5v.  Once I put the resistors on I did get a swing when moving the encoder wheel.  I think it was a high of 2.5v and a low of about .7v, but I don't have time to check it before I leave.  I have no idea why I'm getting 4 flashes of the LED with the resistors and none without.  I've only got 1sw1 1sw2 and the spinner hooked up, 4 flashes looks like player 2 joystick right on the Ultimarc error code list. 

Could the voltage still be too high?  Maybe if I try 1.5k resistors to pull the signal down even further.

Oh well, I'm going to try and forget about it while I'm on vacation.

[RandyT]

I think it was a high of 2.5v and a low of about .7v ....<snip>

Could the voltage still be too high?  Maybe if I try 1.5k resistors to pull the signal down even further.

I've never used the hardware in question, but from a basic digital electronics standpoint, your high doesn't sound high enough.   Also, going from a 1k to 1.5k resistor between the signal and ground won't pull the signal down more.  It will increase the amount of resistance and allow the signal to remain at a higher level.

That being said, it sounds like you are heading in the direction you need.  Check with Andy to see what components are recommended, but I would try a 10k and work my way lower until it is stable and working.

RandyT

[BobA]

Have a good holiday.  I sure it will get sorted out when you get back.
 

[Paladin]

My Tempest spinner now works!  I bought an optic board from fixumdude (from the Buy Sell Trade forum) and it worked first try.  I problably could have made the Atari board work by trying different resistors until I hit the right value, but I figured I'd save my time and original boards.   All I had to do was drill a couple holes to mount the new board to the Tempest spinner and plug it in.