G25 shifter PCB connector

[calan]

Does anyone know what type of connector is used on the G25 shifter PCB, that connects the shifter mechanism to the board? It's a 5-pin connector... with wire colors yellow(2), orange, red, brown, and black.

I need any info I can get on it, including connector type, pin spacing, manufacturer, and a part number/source if possible; either for just the connector and pins or an assembled "pig tail".

I've designed a heavy-duty replacement gated shifter with mechanical simulated clutch, hand brake, etc....and need to make up a cable for it.

Thanks for any help!

[joeb]

Hi,

it's long ago that I opened the shifter, but I'm sure it's a standard
connector: not 2.54mm, something smaller, maybe 2mm??
On the other end (plugged into your wheel), it's a 9er SubD.

On the PCB, there is nothing real exciting, only buttons, one
Chip (?) and another connector for the shifter position. One
remarkable thing is, that the shifter position is not readout by
buttons but by 2 potis (like that in gamepads). This potis
resp. their function can be simulated by buttons and resistors.

I think it's a relative easy job to decode the PCB function
and replace it.

Good Luck

[calan]

Yeah... I already have the shifter built and the pot values decoded, etc. Just waiting on the solenoid for the clutch (should be waiting for me after work), and starting on some clean-up now and sourcing wire, connectors, designing the interface PCB, etc.

I'm going to use the existing PCB from the G25 shifter (for the buttons, d-pad, etc)...just move it to a dedicated panel with new buttons and replace the shifter mechanism with my new one.

I just need to find a part number for the 5 pin connector, and preferably a source for one assembled with about 3 feet of 20-24 gauge wires hanging off of it.

[calan]

I also need the small 2-pin connectors that are used on the wheel switches and the sequential switch on the shifter PCB now that I think about it.

[joeb]

2-pin connector inside the wheel (sequential shifter part)?
I opened all parts and I'm sure all PCB-connectors are of the same
family, different pin counts. On farnell.com, it should be possible
to find this family.

And one final remark: the x/y poties inside the shifter decode
the position in a simple way: y-position just by 2 values,
x-position with 3 values. My idea is to use 5 resistors,5 buttons
and each button in conjuction with a resistor scans one position.

[calan]

...the x/y poties inside the shifter decode the position in a simple way: y-position just by 2 values, x-position with 3 values..

I believe both axis use 3 values, with 2.4v in the y-axis always being neutral, and 2.4v in the x-axis being gears 3 and 4. Reverse uses the x-axis voltage for gears 5 and 6 (about 3.2v) plus the reverse switch closed at 4.8v. The voltage supply on pin 1 (yellow wires) is 4.8v, so with the gear shift in neutral, both axis see equal resistance and read 2.4v.

For anyone interested, here are the actual voltages I measured for each gear:

29687

With those values, it looks like you can set the thresholds up as follows:

X-axis

< 1.3v: gears 1/2
>= 1.3 and <= 3.0: gears 3/4
> 3.0v: gears 5/6/rev

Y-axis

< 0.7v: gears 1/3/5
>= 0.7 and <= 4.0: neutral
> 4.0v: 2/4/6

rev switch = 4.8v: reverse

I'm using 4 SPST limit switches with NO/NC contacts (plus one for reverse), and a simple voltage divider on each axis.

Do you know what the pin spacing or family is for those connectors? It's something like these, but not exactly:

http://www.jst-mfg.com/product/detail_e.php?series=199

[joeb]

Oh sorry, you are right: i forgot the neutral position in y-direction!!
-- lol,stupido -- So ==> 3 levels in y-direction, 3 values, 3 resistors!!

And yes, this are the connectors (more exactly: the same form!).
Just open your shifter chassis, measure the distance of the pins
and the dimension of inner connector chape and compare it with
the description inside the pdf file (.."further informations" on the
JST page).

[calan]

One thing I haven't done yet is to measure the y-axis voltage when in sequential mode. My guess is that it uses the closed sequential switch (4.8v?) plus gear 1/3/5 voltage for shift up, and gear 2/4/6 for shift down...but I'm not sure what those voltages will be since the shifter doesn't travel as far when locked in sequential mode.

I'm hoping that it's still higher (or lower) than the gated thresholds, so I don't have to create two new voltage references for sequential.

[joeb]

I just opened my chassis: the 5- and 6-pin connectors are with
2mm pin distance, the 2-pin connector has 2.54 distance.
The 5-pin plugger has the dimension 3.5mm X 10.6mm, the
6-pin-plugger 3.5mm X 16.6mm (ca.!!).

Sequential shifter: Forget to look after it, but I think it's position
is mesured via buttons, not via potis. So there is no need to
measure the voltage.

[calan]

I just opened my chassis: the 5- and 6-pin connectors are with 2mm pin distance, the 2-pin connector has 2.54 distance.
The 5-pin plugger has the dimension 3.5mm X 10.6mm, the
6-pin-plugger 3.5mm X 16.6mm (ca.!!).

Thanks!

Sequential shifter: Forget to look after it, but I think it's position is mesured via buttons, not via potis. So there is no need to
measure the voltage.

IIRC, there is only one switch which closes when sequential mode is selected... so I think it uses a combination of this and the y-axis pot for up/down shifts.

[joeb]

Forget my last remark, the 2-Pin-connector can't be able to measure
2 positions of the seq. shifter; then there would be a 3-pin connector.
Now I guess the 2-pin-connector ist just connected with a button that
checks if sequential mode is ON or OFF. (I opened the chassis but
without check the sequential mechanism)

If mode=OFF: the gear position is read out via poties (3 x-/y-position
each).
If mode=ON: the seq. position is read out via the y-poti (3 positions).

If both 3-position-groups are identical: ??? => can you check this?
I think this would be interesting to know.

[calan]

The only thing that is different about the y-axis in sequential mode is that the shifter doesn't travel as far, and it therefore will have slightly less voltage output coming from the pot.

What I'm not sure of, is if the processor compares the voltage to a lower threshold in sequential mode, or if it uses the same threshold for both gated and sequential. I'm hoping that it uses the same threshold for both and the voltage is always above (or below) it regardless of the shifting mode.

I'll take some measurements and figure out what is going on with sequential mode this weekend sometime.

[calan]

For future reference...

I got my new shifter hooked up and it works beautifully! I ended up just cutting and reusing the cable going to the original shifter.

29728

The only caveat that I stumbled across is that the order in which the reverse switch gets triggered matters. The G25 firmware expects the reverse switch to be closed first, followed by a low voltage on the y axis to signal reverse....so I had to reposition my reverse micro switch to trigger before the low voltage y-axis switch.

Also, using switched resistors instead of continuously variable potentiometers caused a minor issue in that gears would sometimes be missed in sequential mode due to switch noise/bounce. This was easily fixed by inserting a capacitor between the y-axis input and ground.

[joeb]

Nice work; the black thing in the left: is this a handbrake?
Have you ever thought about an analog handbrake? For a
simple test, I used a analog joystick as handbrake, with
fantastic results in RBR etc. For that, I used the clutch
signal.

The switch resistors: They are only "activated" when a button
is pressed (=gear/neutral used). But in the between phases,
there is no button, so no resistor value?! Hm, I think this can
be solved by a simple a resistor ladder?

[calan]

Nice work; the black thing in the left: is this a handbrake?

Yep

Have you ever thought about an analog handbrake?

Not really. I can't think of any games that I play that support it.

The switch resistors: They are only "activated" when a button is pressed (=gear/neutral used). But in the between phases, there is no button, so no resistor value?! Hm, I think this can be solved by a simple a resistor ladder?

Not sure what you are talking about here. You only need 4 resistors in each axis... one for the high voltage, one for the low voltage, and two of equal value for the neutral voltage (half of the supply). If the high or low resistor is not switched in via a gear position, the controller always sees the output of the two equal resistors (neutral).

[joeb]

One year ago, I found a simple circuit ("circuit 1"),
but it doesnt work (see voltage levels with missing
levels in the between positions).

"Circuit 2" works more or less, with the problem of
bouncing effects (due to Switches). Some caps
can handle this; if not, insert SchmittTrigger and
transitor stage before resistors.

[calan]

Here is a simple schematic that works:

29788

I'm not sure on the capacitor value...it will vary from one board to the next, and is dependent on the final resistor values.

For the potentiometers, you can use about anything, but the ones shown will give the best adjustment in the range needed. (I believe I ended up using fixed resistors of 470 ohms on the y-axis and 1k on the x-axis).

All switches are shown in the normally closed (not activated) position.