DIY Logitech G25/G27 shifter/pedals USB adapter

  • Thread starter RomanST77
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They look really good.. I ended up soldering a few pieces of wires to the 4 pins that matter and then adding a 6" usb cable for the dev-board for 1.1... until I get the solder-paste from China along with building the soldering oven to help with these surface mount components...

Oh, question - I'm using G27 pedals and shifter - the shifter buttons seem odd... like the red ones are 2, 1, 4, 3 instead of 1, 2, 3, 4 so maybe it is pin setting ( g25 is down or up; I need to look back at the sheet you sent, I think down but since the text was switched I switched ) so it is either that or it could be a logitech manufacturing thing, button id doesn't really matter a whole lot... or the refurbished one I got assembled it slightly off.. Also not a big deal.

Were you adding headers to this for an extended board because of the larger chip or was that simply for more memory? Going to check messages in a sec.




This is a bit dirty but color coded tabs ( overboard for dev board lol because no silkscreen and I didn't change it before ordering ).. Also turns out that I may have received 11 boards instead of 10 O_o... I also went with a blue led, it ended up being super-bright so I'll use a dark / frosted element for the box when I sell the excess...

I think I told you I wanted to build wood boxes; I may build a small cnc / router for carving them :-)

Also this is the first surface mount board from start to finish I've done; the usb wires look ugly as hell because I didn't have thin enough wires, and the pads came up and I tried using my heat wand from my rework station for the micro-usb but even after being cooled it just took up pads, etc... the oven will make it look a lot better and I will need to make a jig for the headers if I do decide to do colored headers on excess boards...

They're crooked because of the excess plastic from the break which I filed down and then they didn't stay and this that and the other... I tried using the breadboard to keep them in place but they kept popping out so it was by hand from underneath ( and I couldn't move my head / neck because of nerve damage and severe neck injury so ) meh... It works but "Just because it works, doesn't make it right. - Josh 'Acecool' Moser" :-) so the next will be better... and since I got 11 instead of 10 this was a perfect practice board... I think the color coded since-line headers ( the doubles still haven't arrived; need to ask where they are ) make a lot of sense and wasn't difficult to do ( the single header at a time was annoying, so as said will need to make a jig to make sure they're filed properly and a case so I can inject a thin layer of hot-glue around and a slightly thicker layer between them to hold them together so they behave more like straight line - I may also use super / crazy glue but that can get messy..

I may modify the board when I order by having the usb as a header ( 4 pin as NC / ID isn't needed ) which should fit in that area where it is.. If not, I may then just have 4 larger pads or, even better, have a small connector on the board like Logitech, etc... Then long / short cables can be made, as desired but it'd be "fixed" so there isn't the issue of the connector popping off ( at least until I find a quality connector that isn't $1 to $2 each O_o...

I also like the idea of using hard-mounted cables especially if a box is given because the micro-usb connectors didn't accept the solder at all and was super weak and kept breaking or the pads came up which might be an issue with elecrow ... but with hard-mounted cable with a lock-loop in the box it'd be safe and a long cable isn't needed since the pedals can come up the back of the desk and the shifter goes right and under the lip towards the back and up where the 2 meet...
 

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Luckily this was salvageable! The pads that came off were: top-right ground, bottom-right ground, bottom 1 left from right-ground and I think one more to the left on the bottom... So the 5-pin black ground wire went from pin 5 to the LED ground ( since that trace loops around to where the pads were missing ) to the wire along with the black from the left-grounds... The other 3 were a PAIN to solder and I added the hot glue just in case I dropped it and as an insulator...

The trace for the LED light also lifted but when I wedged the usb micro in between the 2 pads I extended the solder to it and it was fine, but it just popped off so easy each with a TON of solder and I used all 4 pads at the end so it is likely elecrow ( but when I build the reflow oven I'll be able to confirm or deny that ) I may even drill the 2 holes for the usb micro plastic things just to make it easy...

Since you now have the smaller micro usb like I have with the plastic pins that break super-easy - if you haven't added it to the program it wouldn't be hard to measure it all out... I may be able to make the component and share it.

The hot-glue gun I have is annoying; bought at Aldi for $3 and the damned thing wastes half a stick before you're ready to glue because it just seeps out without pressing the trigger and when you do press the trigger, despite having a tight nozzle.. well a lot comes out as you can see ( which is why I want to make a jig for the header thing )...

The software switch between the 25/27 will be nice... Will it be automatically detected or will you need the client to choose? Because there should be a way to check logically which is which but, since I'm new to hardware I'd have to read up on it all; but logically it would be straight forward... ( I'd have to walk-through the wiring diagrams to find the differences, but it shouldn't be difficult to detect which one the user is using )....

OH... I am going to download the 25 and 27 diagrams anyway, pinouts for the db9s because I wanted to look to see if the Logitech Momo pedals would work ( 2 pin holes are covered so I'd need to drill them ) to see the differences... but it probably isn't worth it because 2 pedals although for some people who only have it, if the device supports it with only a software change then that wouldn't be bad... not priority though...
 
The software switch between the 25/27 will be nice... Will it be automatically detected...
Yep, in rev 1.2 it is autodetected.

I wanted to look to see if the Logitech Momo pedals would work
No, inserting momo pedals will result in having short circuit. Have no idea how to workaround this and not interested since momo pedals is crap.
 
Yeah; no worries on those pedals.

I noticed some games require a button for neutral; ie if you shift out of gear, releasing the button for the gear, the game still keeps it in gear until the next one... If there is a way to simulate an additional button, one for neutral would be nice which fires once when a button is released instead of being held ( for controller setup may cause issues ) or to be held...

I'll look at code project a little later.. still working on trying it in games.

Edit: Still waiting on the 10µF caps; I may order from another seller because it is ridiculous how long it is taking... I already have everything else.. And I'll order a kit of caps and resistors for next edition.. Probably will order other caps and resistors with leads too for breadboard designing...

Actually - there's a nice trick - solder them between 2 header pins and then you can put it directly into breadboard or use mail to female cable... I did this for each cap, resistor, crystal, and led.. It works out surprisingly well but can be a pain for the first few - solder them to the short-end... I may hollow out a piece of wood to act as a jig for the different parts.. I am also likely going to order a cap and resistor kit for 0603 with 50 pieces each at a minimum, or if cheaper I'll order them separately...

Any news on the new BOM so I know which other parts to order? As for the remaining boards I have I am working on piecing together a reflow oven project :-)



Once the caps come in then I can focus on programming without the annoyance of having to power it separately, etc...
 
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Just received a Leobodnar cable. All I can say what a dramatic improvement! Not only is the pedals alot more accurate and responsive, the steering wheel seems to have become way more responsive! Not sure exactly why but its quicker to respond to movements in steering input. Ive only played with it for an hour or so and love the difference it makes.

I highly recommend taking the pedals off the stock controller and use an external one like the leo bodnars!
 
Just received a Leobodnar cable. All I can say what a dramatic improvement! Not only is the pedals alot more accurate and responsive, the steering wheel seems to have become way more responsive! Not sure exactly why but its quicker to respond to movements in steering input. Ive only played with it for an hour or so and love the difference it makes.

I highly recommend taking the pedals off the stock controller and use an external one like the leo bodnars!

What a great placebo effect :) I am impressed.
 
I don't really think that wheelbase "knows" for sure if pedals are connected. Instead the wheelbase reads ADC input at steady rate (about 500 Hz for G27, most likely the same number for G920). No matter what numbers are read from ADC this data is filtered (since Logitech pedals are somewhat noisy) and passed to the driver. The only thing changes when you disconnect pedals from wheelbase is numbers in USB HID reports, the wheelbase MCU doesn't change the way it handles this data. So I don't really think this can affect steering wheel movements.

But Bodnar's adapter can handle pedals different way (i.e. apply less filtering) so pedals may feel more responsive. Hovewer where is always a drawback, less filtering = more noise...
 
Hi Roman,

What does USB HID reports refer too? Amount of USB updates per second? If thats the case maybe its reducing the input lag? I definitely feel more response from the wheel. I wasn't expecting a change like this at all. So very odd if I'm perceiving it as a plecebo
 
USB HID report is a short (up to 64 bytes) sequence of numbers describing current state of all HID controls (steering wheel position, each pedal position, each button state). Logitech steering wheels (G25, G27, G29 and G920) send HID reports to PC each 2 ms (500 Hz). Since Logitech firmware is closed I don't know if the wheelbase actually checks wheel and pedals position at this rate but most likely it is and it doesn't change the rate if pedals aren't connected.
 
Once I am set up with the software development environment I'll be contributing auto/dynamic-calibration to this adapter..

I'd like to also modify the driver so the user has more options in the device properties so they can set deadzones ( such as 51% off the end of clutch would meant pressing it 49% physically would register 100% logically - the dynamic calibration system works the same way so if you put a physical stop on the pedal and press it 51% then 51% pressed == 100% logically and if you remove the stop you just press it fully and then 100% == 100% )
 
Note and Advert: I have 9 of these boards fully assembled, updated and programmed, cleaned / washed and packed in a sealed bag ready to be sent out... If anyone is interested in getting one please shoot me a message... Price will be something like $20 plus your choice of shipping method. These do not come with a box / container; you'd need to 3D print your own or make one. I'll eventually get a small / micro cnc and make them out of wood or a 3d printer.. If you want a usb-micro breakout board I can throw on in but you'd need to cut a usb micro wire and then solder the wires to the headers or holes ( header included )...

These come with the following features and / or accessories:

  • Color-Coded columns for the shunts / jumpers for setting to G25/G27 and for Normal boot vs programming mode ( Default the colors are vertical 3-pin RED for Shifter, Vertical 3-pin WHITE for pedals, vertical 2-pin YELLOW for normal boot, Vertical 2-pin WHITE for programming mode ) - NOTE: These colors can be changed if you are color-blind or have a color-deficit - I have many different colors to choose from which should allow for more of a contrast between them - the programming port colors can not be changed unless I put them on the pins where the dupont wires should go ( there'll still be enough room to program ) so I put black on left, white on right which should be a good enough contrast to know the rest of the order; if not let me know and worst case I'll resolder them for you!
  • Color-Coded programming ports ( Black = Ground, Red = 3.3v power, Green = SWCLK [ on STLink V2 ], Blue = Data IO, White = Reset Switch ).
  • Basic Shunts / Jumpers - OR BY REQUEST easy-grip thumb-shunts / jumpers if you decide you want to develop for it where you need to easily move them ( normal shunts / jumpers provided by default in case you put into a box as the thumb ones are slightly higher than the db9 ports ) - just ask... If you only have one type of pedal / shifter unit then I'll provide 1 for the boot mode, or if you have 2 or more pedals / shifters then I'll provide all 3 ( slightly more expensive for me but I won't pass the cost on ) or if you think you'll get more later I'll throw in all 3... Just ask :-)
  • The latest stable firmware / software ( or development by request ) pre-installed..
  • A User-Guide - Which covers the pin-outs in greater detail along with trouble-shooting and warranty information ( I stand behind everything I do both software and hardware - if I messed up a solder joint and something falls off [ which shouldn't happen and I already tested the usb ports to hell and back ] then I'll take care of it for you -- if you put a jumper on the wrong way [ this is why I have colored columns so you know how they fit plus it is outlined in the guide ] and fry the chip, then I will repair it for you and charge you cost of parts [ all of the resistors, caps etc.. are pennies so the big thing is the chip which is $1 to $2 or more and the crystal is slightly more - the rest shouldn't break at all ] + $5 repair fee and return shipping [ replacing all of the resistors, caps, crystal and chip without changing headers or db9 ports would be ~$4 maybe more depending on chip cost and shipping at the time ] )!
  • Warranty - Described in User-Guide. I stand behind my work!

They may come with ( Installing software to start making changes to firmware ):
  • Auto calibration for pedals ( simply depress all pedals once and release when you plug it in and it'll be calibrated just like Logitech does it -- the benefits of this is that you can make a hardware dead-zone to stop the clutch pedal traveling more than 50% and then that range from 0 to 50% becomes 0 to 100% in the software and if you use this on a different computer where you didn't calibrate the pedals using Windows or whichever OS you're using, you don't have to drudge through those menus )
  • Auto calibration for shifter - This is a possibility - I will be looking at options to set up the shifter settings within the hardware without launching the utility by holding 3 buttons on boot or simply 3 or so awkward buttons for 5 seconds ( and if a light can flash or something then I'll do that ) then you simply take it through each gear.. so Neutral you'd move it left and right fully.. 1st gear when in gear you'd move it left and right ( so the software can detect how wide the gate is; each joystick is different... ), 2nd gear the same, and so on ( center gears wobble the most )... Once done you'd hold the same buttons again or simply press a single button... These settings would be saved in the on-board memory ( as the current utility does it ) so it only needs to be done once any time you swap shifters on the same board ( ie your friend brings their shifter although if I can detect hardware id I may allow storing last 5 used )
  • Additional options in the Windows Dialog - This is something I'd really like to add such as artificial dead zones ( while the auto-calibration for pedals will detect the noise when the pedals are idle and ignore it automatically without compromising speed / response ), artificial pedal range ( so you could set 0-100% logical to be 0-50% physical so you only need to press a pedal halfway for it to fully engage [ nice for clutch as it is more realistic for it to disengage fully before being fully depressed and most games require the logical to be at 100% or you encounter issues which is silly ] ), dead zone ( if you have a disability such as a shaky foot and you want it to ignore those motions you can set a percentage of swing to ignore and if there are enough people asking for this then I'll see about coding something more intelligent so it detects your disability wave and filters that from the pedal to give a better ride so instead of a percentage you can shake the pedal at the normal rate and deviations will affect the logical % )... and more...


They do not come with:
  • Micro USB Wire ( I don't have that many left especially since cutting up a few to make hardware debugging tools but in special cases I may be able to send one for $2 random length, color and brand or lack of brand )
  • Box / Container - Eventually I'll make some out of wood using micro cnc or when I get a 3D printer ( but I want to get a 3D printer in order to improve the industry with some mods I've been designing ).. Right now you'll need to make your own... I don't use one on mine - you should be fine as long as it isn't sitting on a metal desk or on electrically conducting material...

Photos of units almost how they come - Random pick:

Temporary seal from dust after final test and cleaning... These will be re-packed with pre-cut foam inserts to fit the nooks properly and then wrapped in foam before being sealed in the envelope and put into a box for shipping....
https://www.dropbox.com/s/y4qqghpae...y_Josh_Acecool_Moser_20170523_110722.jpg?dl=0

Bag opened - no foam as this was just protection from dust...
https://www.dropbox.com/s/cfkzwraxs...th_Foam_for_Shipping_20170523_110741.jpg?dl=0

Top down photo with jumpers / shunts removed to show colors...
https://www.dropbox.com/s/1m463k6he...Top_Down_Random_Pick_20170523_110807.jpg?dl=0


I have 1 spare STLinkV2 which is gold in color - running latest firmware... I may sell this if someone absolutely needs it as they take forever from China to arrive... For now I use 1 for developing for the board and 1 for an Arduino board I'm doing another project for...




Post:

I finished putting all 10 together ( the first board I did I desoldered all components as the supplier I used gave me 11 which was nice and I'm using that board as dev board ) and got the usb connectors to work with soldering paste I may have already mentioned...


Does anyone have any info handy regarding the hidden buttons for G25 / G27? I'm doing research on those so I can add support to version 1.1 ( or later if different chip needed; need to install software to rewrite the hex files so I can add auto calibration and more )... I'm going to take my G27 shifter apart to look and see what I find and then implement the buttons; I also want to see if I can remove the vertical shift block for all other gears ( imagine 12 slots for all gears [ if possible then for games such as the Truck Simulators instead of a button the high-low { ie 1/2 would be first gear up, and first gear pushed down } could be for that, then the next set could be a switch ie the splitter? ] then 7 gears won't be an issue; ie we won't need to use reverse for 7th and another button for reverse )

I just need to verify the data that it isn't too much for the pin but it'll probably be fine...

I'll be installing EmBitz 1.11 for development on the firmware - I already have Visual Studio in case I mod the shift calibrator ( but I will likely have a shift calibration system act dynamically, or hold 3 buttons on shifter when plugging in or something [ or simply several awkward buttons ] and if I can get the light to flash then Neutral left right shake, first gear then move left right [ to detect how far the walls need to extend to prevent accidental shift ] and if you want gear to engage on the hump can then hold it in there and press a button.... ) but I probably won't touch that in favor of auto calibration...











Below are photos also some tips for soldering, cleaning, etc... if you're interested in building these... Photos of some debugging tools I made to help with construction ( easy to do [ for the usb micro-to-micro you could simply have micro to wires to use ohm-meter on instead of what I did - I did that way because I purchased too many of the usb micro breakout boards although since the next revisions are getting smaller I'll likely opt for a micro-header to this inside a box which I'll likely make out of wood on a micro-cnc ] )

Photos:

Debugging and Programming cables ( pink usb is ST Link V2 with 10cm F/F wires hot-glued together to make it easier to plug and program )[ Other wire is usb micro on both ends -spliced usb cable and I bought ( too many ) usb-micro-breakout boards so I use this to test the connectivity of the usb connector to ensure no shorts and so I can look at certain points on the board to ensure everything is connected properly so I know if I need to retouch a solder joint before plugging it in ]..

https://www.dropbox.com/s/cpril0rlo...d_Programming_Cables_20170523_093609.jpg?dl=0

https://www.dropbox.com/s/tkyael05p...ming_Cables_Top_Down_20170523_093543.jpg?dl=0

9 Units freshly assembled, updated and programmed... Cycle was pre-wash, assemble, test using debugging cables, touch-up if necessary ( 1 unit needed resistor touched up and 1 had a short in usb from too much paste underneath because the paste was dry on that one before I added more flux to the mid - SODA lead-free soldering paste ), power test, update / programming, test all buttons ( this is where I noticed the resistor issue on the one; bad connection, ie didn't connect so the gears didn't emulate buttons ) and gears and pedals, final wash to rid of all flux / oils and left-over solder spatter if any ( I usually solder at just above melting ), re-test and confirm all working, then seal in bag ( partially so if I end up updating software I can update these before they go out ) to prevent cat hair and dust from contaminating.......... freshly cleaned boards...

Note: Initial board clean was done with basic soap and water ( won't harm it )... Post assembly cleaning methods ( Soap and water CAN be used but it takes a long time to dry and you shouldn't let it sit, you'd need to blow it out using a compressor - NOTE: I recommend the other method )... Recommended method for cleaning off all flux, etc... after assembly... I used a light to medium stiff round brush and 91% alcohol and the brush to get it all over the board and everywhere needed in decent quantity... The board should glisten.. Next take a stiff nylon bristle brush ( like the 3 pack at harbor-freight with bristles + metal except you use the 1 brush without any metal on it ) and scrub like hell... If anything falls off, you did something wrong - the solder joint wasn't strong enough ( this shouldn't happen at all as long as you heated the pad and the wire before applying solder if hand-soldering... if using solder-paste then simply use solder-paste and heat-gun and you'll be fine ) but that shouldn't happen... the alcohol will evaporate; note don't get it into the ports where you plug the shifter / pedal cable; it isn't needed there... only on the board surface - front and back...

https://www.dropbox.com/s/9i6rfbjcr...Sealed_Ready_To_Ship_20170523_093615.jpg?dl=0

Programming port ( Asked question regarding height of RomanST77's if he snipped the metal as my L pins are the same length so I simply set them up high but I don't know if I'm going to set them down a bit or leave them ) color coded with black / white on outer to act as key for those who suffer from color-blindness or varying color-deficits ( Blk = Ground, Red = Power 3.3v, Green = SW CLK, Blue = Data IO, White = Reset ) - I ship these with a header strip connecting all pins to help protect against inward bends and breaks...

https://www.dropbox.com/s/lgs8mw8b1...ter_Programming_Port_20170523_093315.jpg?dl=0

Top down view of the cleaned board [ mine in use, with cats in house so you may see some hair or dust but the ones shipped should be completely free or as completely free as possible as I cleaned them and then sealed them in non-electrically conducting PVC bags ] ( the one in use; I ship these with standard shunts / jumpers but can swap them out for thumb-shunts / jumpers for those that want easier time swapping if they decide to do dev work )

https://www.dropbox.com/s/14m2m4pt0...ew_Post_Build_Washed_20170523_093308.jpg?dl=0

I did experiment a bit with solder used on some.. The reason my crystal looks like dull solder joints is because I used paste for the main connection and added that for extra stability because I'm using it for dev so that top layer doesn't matter - all solder used is LEAD FREE....

If you decide to follow the colored header method I used for the programming port; feel free.. A simply trick is to use a razor-knife to cut the different color headers apart cleanly ( but with a little extra on the outside to apply pressure against the neighbor pins / plastic stand-offs [ I almost decided to rotate the plastic so the cuts would face up / down if looking at top-down but I found the extra force applied to the neighbors helped with soldering because it locked it in place ] ) and then using a solid 5 long un-cut solid plastic header-standoff piece to join the pins the programmer plugs into ( hovering over the board ) together... Then the entire contraption holds itself together nicely and when you put them in the through-board holes it won't budge which is really nice and you solder it while keeping the 5 piece header-stick on it and can be used as stabilizer / protector for shipping and you can keep it on while programming; there is just enough grab on the Dupont female pins that it can remain on as a retainer...

https://www.dropbox.com/s/2qvs5cpoy...ing_Headers_Assembly_20170523_102521.jpg?dl=0
 
@Acecool I am working on a project where I have to design my own wheel system. As you guys discussed before, I am able to send data from my controller to the game but still cannot get ffb data from the game. Kindly help If you have successfully configured how to introduce controller (Arduino Leonardo) as logitech 25 by tweaking the HID headers .... :-D
 
@Acecool I am working on a project where I have to design my own wheel system. As you guys discussed before, I am able to send data from my controller to the game but still cannot get ffb data from the game. Kindly help If you have successfully configured how to introduce controller (Arduino Leonardo) as logitech 25 by tweaking the HID headers .... :-D

Look here, might be helpful: https://github.com/matlo/GIMX-firmwares
 
img_3947-jpg.582622


This board is most interesting....
is it still available?
is it compatible with for instance the G29?
Are those 2 holes at the bottom mounting holes?
I count 16 connections which covers the 4 red/4 black/8way Dpad. Is this how it is laid out?

The reason I ask is I have a prototype Carbon F1 wheel which currently bolts straight to the G27, which only has 6 buttons on the wheel as you know. The G29 Logitech moved the push buttons from the shifter onto the wheel. If this board attaches to the G29 the same way it would mean I could make my F1 wheel compatible with the G29 set.

Also its nicely low profile.

Any help would be appreciated
 
This board will not work with G29, it has slightly different electronics in the wheel. Although I can do it for G29 too there is no such demand currently. The board is made for this project:

l3pembpvrfywy1du9ed_msw9l3q.jpeg


Will work with G27 and G25. G29 is not supported and not planned.
 
Thats a nicely finished bit of kit.

Mine I am looking at how I could connect it to all the different wheel hubs but maintain the original button inputs.

20180127_182749.jpg


This is still being worked on and only mounts to the G27/25 at the moment. I have an adapter plate drawn up ready to be cnc'd so it can mount to TM or direct drive units

Its the circuits that are holding me back as I know nothing about creating pcbs.
 
Thats a nicely finished bit of kit.
Thanks! Actually I only did electronics for this project, the wheel itself was made by other guy, have a look here:
http://forum.simracing.su/index.php?showtopic=2543&st=620#entry232980
He's going to sell a small number of this wheels soon...

Mine I am looking at how I could connect it to all the different wheel hubs but maintain the original button inputs.
View attachment 710682
This is still being worked on and only mounts to the G27/25 at the moment. I have an adapter plate drawn up ready to be cnc'd so it can mount to TM or direct drive units.

Its the circuits that are holding me back as I know nothing about creating pcbs.
Looks great! I can help with electronics for G25/G27, but I know very little about G29 at the moment. Need a working circuit from G29 wheel to figure out how to interface with it.
 
Looks great! I can help with electronics for G25/G27, but I know very little about G29 at the moment. Need a working circuit from G29 wheel to figure out how to interface with it.

I understand, I don't have one myself nor know anyone with one so can't help with pics. All I have seen is some online guides showing how to take it apart.



Counting the buttons on the front comes to 22, which is the same as the G27 count. the only differences I can see are the red dial thing (don't know how it works) and a sliding switch on top behind the rev lights.

From what I have seen, it still uses the single 6 pin XH plug from the base to the hub. Logitech have then done what your board does and moved all the button inputs from the shifter into a housing around the wheel leaving only the gear shifter..on the shifter :rolleyes:.

Looks great!
Thanks, I too had to go to a prototyper who molded my design out of CF. But now I've got the molds so can make more in future. But finish the prototype first :)
 
From what I have seen, it still uses the single 6 pin XH plug from the base to the hub. Logitech have then done what your board does and moved all the button inputs from the shifter into a housing around the wheel leaving only the gear shifter..on the shifter :rolleyes:.
Most likely they simply moved 2 shift registers from shifter to the wheel, so now there are 3 PISO (parallel-in-serial-out) shift registers (8x3=24 buttons) in the wheel and zero in the shifter.
 
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